Fermentation

12 pages, 995 KiB

Open AccessArticle

Bacteriocin Production by Lactiplantibacillus plantarum LD1 in Solid-State Fermentation Using Lignocellulosic Substrates

by Pushpa Rani, Bijender Singh and Santosh Kumar Tiwari

Fermentation 2025, 11(4), 233; https://doi.org/10.3390/fermentation11040233 - 21 Apr 2025

Abstract

In this study, solid-state fermentation for growth and bacteriocin production by Lactiplantibacillus plantarum LD1 was carried out using wheat bran, a lignocellulosic substrate. This is the first report showing bacteriocin production using L. plantarum LD1 in solid-state fermentation. Wheat bran supported higher production [...] Read more.

In this study, solid-state fermentation for growth and bacteriocin production by Lactiplantibacillus plantarum LD1 was carried out using wheat bran, a lignocellulosic substrate. This is the first report showing bacteriocin production using L. plantarum LD1 in solid-state fermentation. Wheat bran supported higher production of bacteriocin (391.69 ± 12.58 AU/mL) than other substrates. Appropriate conditions were achieved using statistical designs. Significant factors identified by Plackett–Burman Design and their interactions were studied using response surface methodology. Enhanced production of bacteriocin (582.86 ± 0.87 AU/mL) and optimal growth (log₁₀ CFU/mL 8.56 ± 0.42) were attained in wheat bran medium supplemented with peptone (1.13%), yeast extract (1.13%), glucose (1.56%), and tri-ammonium citrate (0.50%). Growth in non-optimized medium (MRS) was almost similar (log₁₀ CFU/mL 8.15 ± 0.20), but the bacteriocin production level was lower (391.69 ± 0.58 AU/mL). Bacteriocin production was sustainable using varied quantities of wheat bran, showing the suitability of the optimized bioprocess for large-scale production. The cost for bacteriocin production in the optimized medium was found to be 444,583.60 AU/USD, which is about 4 times more economical than the cost of the commercial MRS medium, 121,497.18 AU/USD). Thus, an almost 1.5-fold improvement in bacteriocin production was achieved using wheat bran as the substrate. The cost of the production medium was reduced by approximately 25%, making the bioprocess economical. Full article

(This article belongs to the Special Issue Lignocellulosic Biomass Valorization)

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44 pages, 1038 KiB

Open AccessArticle

Evaluation of Environmental Sustainability of Biorefinery and Incineration with Energy Recovery Based on Life Cycle Assessment

by Alejandra Gabriela Yáñez-Vergara, Héctor Mario Poggi-Varaldo, Guadalupe Pérez-Morales, Perla Xochitl Sotelo-Navarro, América Alejandra Padilla-Viveros, Yasuhiro Matsumoto-Kuwahara, Teresa Ponce-Noyola and Rocío Sánchez-Pérez

Fermentation 2025, 11(4), 232; https://doi.org/10.3390/fermentation11040232 - 21 Apr 2025

Abstract

Based on Life Cycle Assessment (LCA) and ISO standards, we compared the global environmental sustainability (ES) of two technologies that process the organic fraction of municipal solid waste (OFMSW) in Mexico. The first technology was a biorefinery (BRF) known as HMEZSNN-BRF (abbreviation for [...] Read more.

Based on Life Cycle Assessment (LCA) and ISO standards, we compared the global environmental sustainability (ES) of two technologies that process the organic fraction of municipal solid waste (OFMSW) in Mexico. The first technology was a biorefinery (BRF) known as HMEZSNN-BRF (abbreviation for Hydrogen-Methane-Extraction-Enzyme-Saccharification/Nanoproduction Biorefinery); it produces the gas biofuels hydrogen (H) and methane (M), organic acids (E), enzymes (Z), saccharified liquors (S), and bionanobioparticles (BNBPs) in a nanoproduction stage (NN). The second technology was incineration with energy recovery (IER). An LCA was performed with a functional unit (FU) of 1000 kg of OFMSW. The BRF generates 166.4 kWh/FU (600 MJ) of net electricity, along with bioproducts such as volatile organic acids (38 kg), industrial enzyme solution (1087 kg), and BNBPs (40 kg). The IER only produces 393 net kWh/FU electricity and 5653 MJ/FU heat. The characterization potential environmental impacts (PEIs) were assessed using SimaPro software, and normalized PEIs (NPEIs) were calculated accordingly. We defined a new variable alpha and the indices σ-τ plane for quantifying the ES. The higher the alpha, the lower the ES. Alpha was the sum of the eighteen NPEIs aligned with the ISO standards. The contributions to PEI and NPEI were also analyzed. Four NPEIs were the highest in both technologies, i.e., freshwater and marine ecotoxicities and human non-carcinogenic and carcinogenic toxicities. For the three first categories, the NPEI values corresponding to IER were much higher than those of the BRF (58.6 and 8.7 person*year/FU freshwater toxicity; 93.5 and 13.6 marine ecotoxicity; 12.1 and 1.8 human non-carcinogenic toxicity; 13.7 and 13.9 human carcinogenic toxicity, for IER and the BRF, respectively). The total α values were 179.1 and 40.7 (person*yr)/FU for IER and the BRF, respectively. Thus, the ES of IER was four times lower than that of the BRF. Values of σ = 0.592 and τ = −0.368 were found; the point defined by these coordinates in the σ-τ plane was located in Quadrant IV. This result confirmed that the BRF in this work is more environmentally sustainable (with restrictions) than the IER in Mexico for the treatment of the OFMSW. Full article

(This article belongs to the Special Issue Microbial Biorefineries: 2nd Edition)

12 pages, 923 KiB

Open AccessArticle

The Effects of a Dietary Intervention with a Synbiotic Beverage on Women with Type 2 Diabetes, Overweight, or Obesity

by Paola Rodríguez-Rugarcía, Leonel Cuamatzin-García, María de Lourdes Meza-Jiménez, Ma. del Rocío Baños-Lara, Diego Salatiel Zaragoza-Maldonado, Juan Carlos Rodríguez-Espinosa, Erika Lozada-Pérezmitre and Beatriz Pérez-Armendáriz

Fermentation 2025, 11(4), 231; https://doi.org/10.3390/fermentation11040231 - 21 Apr 2025

Abstract

Introduction: Non-communicable chronic diseases, such as overweight and obesity, are considered a high risk for type 2 diabetes. Globally, there are 536.6 million people with diabetes. Mexico has a high prevalence of these diseases. Objective: The objective of this study was to evaluate [...] Read more.

Introduction: Non-communicable chronic diseases, such as overweight and obesity, are considered a high risk for type 2 diabetes. Globally, there are 536.6 million people with diabetes. Mexico has a high prevalence of these diseases. Objective: The objective of this study was to evaluate the effects of a synbiotic beverage and a 12-week dietary intervention on body composition and biochemical parameters in women with T2D, overweight, or obesity as an additional strategy for treatment. Methods: This was a double-blind, randomized, and experimental study of a 12-week dietary intervention with a synbiotic fermented beverage with n = 51 women divided into four groups: G1 followed a moderate calorie-restricted diet, G2 followed the same moderate calorie-restricted diet and consumed a synbiotic beverage, G3 only consumed the synbiotic beverage, and G4 consumed a placebo beverage. Results: Significant changes were seen in BMI (p < 0.001) and fat mass (kg) (%) (p < 0.001) after the 12-week dietary intervention, proving that the synbiotic beverage had an effect on body composition. Conclusions: Significant decreases in different body composition and biochemical profiles were seen, showing the benefits of the beverage. A dietary intervention and the consumption of a fermented beverage could be an additional treatment for non-communicable diseases. Full article

(This article belongs to the Special Issue Recent Advances in Microbial Fermentation in Foods and Beverages)

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16 pages, 3945 KiB

Open AccessArticle

Deletion of the Class 1 Histone Deacetylase PsHos2 Induces Secondary Metabolic Perturbations in the Sea Cucumber-Associated Penicillium sclerotiorum

by Peipei Zhao, Jiaying Lin, Qingqing Zhang, Tanghui Zhang, Guoliang Zhu, Chengwei Liu, Qinghua Wu, Jianzhao Qi, Minglei Li, Lixin Zhang and Xuekui Xia

Fermentation 2025, 11(4), 230; https://doi.org/10.3390/fermentation11040230 - 21 Apr 2025

Abstract

The long-term coexistence of sea cucumber-associated microorganisms with their host enables them to jointly withstand the unique marine ecological environment, and possess great potential for producing various natural products. However, under conventional laboratory conditions, most biosynthetic gene clusters (BGCs) in these microorganisms remain [...] Read more.

The long-term coexistence of sea cucumber-associated microorganisms with their host enables them to jointly withstand the unique marine ecological environment, and possess great potential for producing various natural products. However, under conventional laboratory conditions, most biosynthetic gene clusters (BGCs) in these microorganisms remain silent, necessitating the establishment of effective activation strategies for exploring bioactive secondary metabolites (SMs). Histone acetylation status regulates chromatin structure and plays a crucial role in cellular physiology and fungal secondary metabolism. Penicillium sclerotiorum SD-36 was isolated from sea cucumbers in our previous study. Genome sequencing results indicate that this strain harbors as many as 52 BGCs, suggesting it holds a wealth of genetic resources essential for synthesizing diverse SMs. Here, we describe the impact of a class 1 histone deacetylase (HDAC), PsHos2, on secondary metabolism of sea cucumber-associated Penicillium sclerotiorum SD-36. The colony morphology and SM profile of ΔPsHos2 exhibited significant changes, with the emergence of multiple new compound peaks. Six compounds, including five azaphilones, which are characterized by a pyranoquinone core structure, were isolated from ΔPsHos2, and seventeen unreported potential azaphilone-related nodes were obtained using molecular networking based on LC-MS/MS. Transcriptome analysis revealed that PsHos2 influenced the expression of 44 BGC core genes. Specifically, seven genes within cluster 86.1, the putative BGC for azaphilones, were upregulated, including two polyketide synthase (PKS) genes. The results indicate that regulation based on class 1 HDACs is an important strategy for enhancing SM synthesis in sea cucumber-associated fungi and expanding the resources of marine natural products. Full article

(This article belongs to the Special Issue New Research on Fungal Secondary Metabolites, 3rd Edition)

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16 pages, 2303 KiB

Open AccessArticle

Bioproduction of Nordihydroguaiaretic and Ellagic Acid from Creosote Bush Leaves (Larrea tridentata) Using Solid-State Fermentation with Aspergillus niger GH1

by Alonso Ascacio-Valdés, Cynthia L. Barrera-Martínez, Juan A. Ascacio-Valdés and Leonardo Sepúlveda

Fermentation 2025, 11(4), 229; https://doi.org/10.3390/fermentation11040229 - 19 Apr 2025

Viewed by 105

Abstract

Creosote bush (Larrea tridentata), a shrub distributed across approximately 19 Mha of arid North American regions, has traditional applications in folk medicine due to the presence of bioactive molecules such as nordihydroguaiaretic acid (NDGA) and ellagic acid (EA). This study investigated [...] Read more.

Creosote bush (Larrea tridentata), a shrub distributed across approximately 19 Mha of arid North American regions, has traditional applications in folk medicine due to the presence of bioactive molecules such as nordihydroguaiaretic acid (NDGA) and ellagic acid (EA). This study investigated the implementation of a solid-state fermentation (SSF) optimization process employing creosote bush leaves as substrate using Aspergillus niger GH1 to improve NDGA and EA extraction. This study was based on previous research by our group that identified key parameters for NDGA production in a related SSF system. Creosote bush is a recognized source of these bioactive compounds, which possess antioxidant and anti-inflammatory properties. Conventional extraction methods often exhibit limitations in efficiency and sustainability. The efficacy of A. niger GH1 in SSF has been previously established with diverse substrates. In this study, A. niger GH1 was employed in an SSF process utilizing creosote bush leaves as a substrate using a Box–Behnken experimental design. The accumulation of NDGA and EA, which were quantified by HPLC-MS, yielded values of 1.20 ± 0.32 mg g⁻¹ for EA and 7.39 ± 0.52 mg g⁻¹ for NDGA. In vitro antioxidant assays (DPPH and ABTS) demonstrated significant antioxidant activity, with inhibition percentages of 55.69% and 84.84%, respectively. These results indicate that A. niger GH1-mediated SSF using Creosote bush leaves is a viable and sustainable strategy for producing these valuable bioactive compounds. Full article

(This article belongs to the Special Issue Fermentative Production of Valuable Chemicals from Lignocellulosic Biomass)

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22 pages, 1183 KiB

Open AccessReview

Application of Wine Yeast Starter Cultures in the Production of Grape and Fruit Wines

by Hrvoje Pavlović, Vlatka Petravić Tominac, Darko Velić, Tanja Mađarević Pavetić, Vesna Zechner-Krpan and Natalija Velić

Fermentation 2025, 11(4), 228; https://doi.org/10.3390/fermentation11040228 - 18 Apr 2025

Viewed by 218

Abstract

Significant advances in winemaking equipment and processes, as well as a deeper understanding of the role of yeast, have significantly improved wine quality throughout history. This paper examines critical aspects related to the use of commercial wine yeast starter cultures in the fermentation [...] Read more.

Significant advances in winemaking equipment and processes, as well as a deeper understanding of the role of yeast, have significantly improved wine quality throughout history. This paper examines critical aspects related to the use of commercial wine yeast starter cultures in the fermentation of grape and fruit wines, with a focus on berry wines and blackberry wine, which is the most predominant berry wine in Croatia. While the production of grape wines remains the most significant, fruit wines are gaining importance due to their composition, which contains a variety of bioactive compounds. Although spontaneous fermentation is still preferred by some winemakers, controlled or inoculated fermentation, based on the use of wine yeast starter cultures, is predominantly employed in modern winemaking. The selection of suitable yeast strains for grape wines is easier than for fruit wines, as the broader availability of commercial yeasts for grape wines contrasts with the limited selection offered for fruit wine production due to the smaller fruit wine market. The selection of Saccharomyces and, more recently, non-Saccharomyces yeast strains with desirable characteristics are crucial for the production of high-quality wines. Selection criteria for wine yeasts have evolved to meet modern consumer preferences and focus on technological properties, secondary flavor development and health effects. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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15 pages, 4062 KiB

Open AccessArticle

New Halophilic Community Degrades Plastics: A Metagenomic Study

by Nikolay Krumov, Nikolina Atanasova, Ivanka Boyadzhieva, Tsvetelina Paunova-Krasteva, Kaloyan Berberov, Kaloyan Petrov and Penka Petrova

Fermentation 2025, 11(4), 227; https://doi.org/10.3390/fermentation11040227 (registering DOI) - 18 Apr 2025

Viewed by 172

Abstract

Biodegradation is an advanced method for reducing plastic waste in the environment, involving the participation of microbial communities with plastic-degrading properties. Our study presents a novel halophilic community isolated from the plastic-contaminated region in Burgas Lake, Bulgaria. In a medium containing 15% sodium [...] Read more.

Biodegradation is an advanced method for reducing plastic waste in the environment, involving the participation of microbial communities with plastic-degrading properties. Our study presents a novel halophilic community isolated from the plastic-contaminated region in Burgas Lake, Bulgaria. In a medium containing 15% sodium chloride, the community can degrade a significant amount of polycaprolactone (PCL) as a sole carbon source, as well as the plastics polystyrene (PS) and polypropylene (PP), albeit to a lesser extent. The community showed high hydrophobicity and the ability to form a biofilm on PCL beads, as well as high esterase activity and significant biodegradation capacity, as demonstrated by measuring the weight of the PCL material after cultivation for 4 and 8 weeks. Moreover, a scanning electron microscopy (SEM) analysis revealed visible cracks, craters, and holes in the surface of the polymer particles. The metagenomic study revealed that Halomonas profundus dominated the community with a proportion of 95.13%, followed by Alloalcanivorax venustensis (2.73%), Chromohalobacter marismortui (0.72%), and Halomonas caseinilytica (0.78%). However, most of the species in the community were not previously known as PCL-degrading. Thus, studying the diversity of the halophile community can significantly improve our fundamental understanding and clarify their potential applications for environmental and water–plastic remediation. Full article

(This article belongs to the Special Issue Microbial and Enzymatic Degradation of Plastics)

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36 pages, 3365 KiB

Open AccessReview

Advances in Mead Aroma Research: A Comprehensive Bibliometric Review and Insights into Key Factors and Trends

by Amanda Felipe Reitenbach, Adriana Sturion Lorenzi, Grace Ferreira Ghesti, Paula Christina Mattos dos Santos, Igor Murilo Teixeira Rodrigues, Ananda Costa Barbosa, Rodrigo Ribeiro Arnt Sant’Ana, Carlise Beddin Fritzen-Freire, Bahareh Nowruzi and Vívian Maria Burin

Fermentation 2025, 11(4), 226; https://doi.org/10.3390/fermentation11040226 - 17 Apr 2025

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Abstract

This article examines the key factors influencing the aromatic profile of mead, which is increasingly popular in artisanal markets worldwide. Based on a bibliometric review of 44 scientific studies, the analysis highlights the significant role of honey type in shaping mead’s sensory characteristics. [...] Read more.

This article examines the key factors influencing the aromatic profile of mead, which is increasingly popular in artisanal markets worldwide. Based on a bibliometric review of 44 scientific studies, the analysis highlights the significant role of honey type in shaping mead’s sensory characteristics. Acacia honey contributes subtle floral notes, while eucalyptus honey brings bolder, resinous aromas. The bibliometric analysis also emphasizes fermentation conditions, such as temperature and yeast selection, as crucial factors. Lower fermentation temperatures help preserve volatile compounds, enhancing fruity and floral aromas, while higher temperatures lead to increased concentrations of undesirable higher alcohols. Additionally, aging mead in oak barrels for 6 to 12 months adds complexity by introducing vanilla, coconut, and spice notes from the wood’s phenolic compounds. The maturation process, including its duration and storage conditions, also enables the flavors to blend and develop over time. Moreover, the addition of herbs and fruits during fermentation or maturation has been proven to introduce new layers of aroma and flavor, with ingredients like citrus, berries, and aromatic herbs enhancing the final product with fresh, lively notes. The potential of non-Saccharomyces yeasts is also explored as an alternative for enriching aromatic profiles, with the capacity to introduce unique sensory characteristics, including diverse flavor profiles and regional or terroir-based variations. Finally, the bibliometric review reinforces the importance of selecting appropriate ingredients and controlling fermentation processes to improve mead quality. It also suggests exploring microbiomes, exotic honey varieties, and the use of herbs and fruits for even more distinct aromatic profiles. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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14 pages, 1558 KiB

Open AccessArticle

Biocatalytic Potential of a Raoultella terrigena-Derived Lipolytic Enzyme for High-Performance Detergents

by Mfezeko Noxhaka, Nonso E. Nnolim, Lindelwa Mpaka and Uchechukwu U. Nwodo

Fermentation 2025, 11(4), 225; https://doi.org/10.3390/fermentation11040225 - 17 Apr 2025

Viewed by 156

Abstract

Dump sites harbour microorganisms with potential for environmentally friendly industrial applications. This study assessed the lipolytic activity of municipal dumpsite-associated bacteria and evaluated the stability of the most potent isolate’s lipolytic enzyme against laundry detergents. It also examined the crude lipase’s ability to [...] Read more.

Dump sites harbour microorganisms with potential for environmentally friendly industrial applications. This study assessed the lipolytic activity of municipal dumpsite-associated bacteria and evaluated the stability of the most potent isolate’s lipolytic enzyme against laundry detergents. It also examined the crude lipase’s ability to remove stains from cotton fabric. Among twelve bacteria isolated, five demonstrated notable halo zones on tributyrin agar plates. The diameters (mm) were MN38 (11 ± 1.4), MN1310 (8.5 ± 0.7), MN28 (6.5 ± 0.71), MN18 (7.0 ± 1.4), and MN310 (8.15 ± 0.21). Quantitative analysis revealed that MN38 exhibited the highest lipase activity (14.76 ± 0.27 U/mL), while MN1310 showed the lowest (6.40 ± 0.85 U/mL). Nucleotide sequence analysis identified the isolates as Raoultella terrigena veli18 (MN38), Stenotrophomonas maltophilia veli96 (MN1310), Viridibacillus sp. veli10 (MN28), Stenotrophomonas sp. veli19 (MN18), and Klebsiella sp. veli70 (MN310). The crude lipase from R. terrigena veli18 maintained 73.33%, 52.67%, 55.0%, and 54.0% of its original activity after 60 min of exposure to Sunlight, Surf, Maq, and Omo, respectively. Adding crude lipase to enzyme-free laundry detergents significantly enhanced their cleaning efficacy, completely removing oil stains from cotton fabric. This performance of R. terrigena veli18 crude lipase highlights its potential as an effective detergent bio-additive. Full article

(This article belongs to the Special Issue Microbial Production of Industrial Enzymes)

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21 pages, 2430 KiB

Open AccessArticle

Oxidative, Inflammatory, and Constipation Stress Modulation by a Heteropolysaccharide from Lacticaseibacillus rhamnosus CRL75

by René Emanuel Lobo, Ana Magdalena Ávila, Jonathan Laiño, Verónica Molina, Diego Navarro, María Inés Gómez, María Inés Torino and María Pía Taranto

Fermentation 2025, 11(4), 224; https://doi.org/10.3390/fermentation11040224 - 17 Apr 2025

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Abstract

Lacticaseibacillus (L.) rhamnosus CRL75 is a lactic acid bacterium (LAB) isolated from local dairy products, demonstrating significant adaptation in skimmed milk (FM75). In this context, CRL75 exhibited high microbial growth (3.63 ± 0.18 log CFU·mL⁻¹), strong acidification (9.20 ± [...] Read more.

Lacticaseibacillus (L.) rhamnosus CRL75 is a lactic acid bacterium (LAB) isolated from local dairy products, demonstrating significant adaptation in skimmed milk (FM75). In this context, CRL75 exhibited high microbial growth (3.63 ± 0.18 log CFU·mL⁻¹), strong acidification (9.20 ± 0.10 g·L⁻¹ lactic acid, and 2.40 ± 0.10 pH units), and increased viscosity in FM75 after 16 h of fermentation. Additionally, this LAB strain produces both capsular polysaccharides (CPS+) and extracellular polysaccharides (EPS75), contributing to a ropy phenotype (>10 cm). The purified EPS75 (70.70 ± 3.25 mg·L⁻¹) displayed low molecular weight (12.7 kDa), with galactose and glucose as its primary monomers in a 4:1 ratio. In aqueous environments, EPS75 exhibited an extended size (147 nm), a random coil structure, and macromolecular aggregation. Furthermore, vibrational spectroscopy confirmed the presence of a neutral EPS with high thermal stability. Additionally, EPS75 exhibited dose-dependent antioxidant activity, effectively reducing metal ions (Fe³⁺, Mo⁶⁺, and Mn⁷⁺) and stabilizing radicals (ABTS^•+, HO^•, O₂^•−, and HOO^•). The biopolymer also demonstrated immunostimulatory and anti-inflammatory effects in RAW 264.7 cells. In vivo assays using Balb/c mice indicated that both EPS75 and FM75 prevented constipation, suggesting their potential as natural and safe agents for constipation-related disorders. Due to its viscosifying and health-promoting attributes, CRL75 offers promising applications for functional dairy products. Full article

(This article belongs to the Special Issue Applications of Lactic Acid Bacteria in Fermented Foods and Beverages)

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20 pages, 2004 KiB

Open AccessArticle

Antioxidant and ACE-Inhibition Activities After In Vitro Digestion of a Non-Fermented Dairy Beverage Enriched with Postbiotics of Lactobacillus spp.

by Norma Angélica Bolivar-Jacobo, Raúl Alberto Reyes-Villagrana, Martha María Arévalos-Sánchez, Ana Luisa Rentería-Monterrubio, Eduardo Santellano-Estrada, Nora Aidee Salas-Salazar and América Chávez-Martínez

Fermentation 2025, 11(4), 223; https://doi.org/10.3390/fermentation11040223 - 16 Apr 2025

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Abstract

Postbiotics are recently gaining consumer attention for their potential health benefits. This study aimed to examine the effects of supplementation of a non-fermented dairy beverage with postbiotics derived from Lactobacillus acidophilus and Lactobacillus helveticus on antioxidant (DPPH, ABTS, FRAP, and ORAC), antimicrobial, and [...] Read more.

Postbiotics are recently gaining consumer attention for their potential health benefits. This study aimed to examine the effects of supplementation of a non-fermented dairy beverage with postbiotics derived from Lactobacillus acidophilus and Lactobacillus helveticus on antioxidant (DPPH, ABTS, FRAP, and ORAC), antimicrobial, and ACE-inhibition activities before and after in vitro digestion. Three dairy beverages were elaborated: without the addition of postbiotics (T0), with Lactobacillus acidophilus postbiotics (T1), and with Lactobacillus helveticus postbiotics (T2). Before in vitro digestion, T2 presented higher antioxidant activity (p < 0.05). And, after in vitro digestion, except by the ABTS method, T1 and T2 presented the highest antioxidant activities (p < 0.05) and bioaccessibility indexes (p < 0.05). Regarding ACE-inhibition activity, before in vitro digestion, there were no differences among treatments (p > 0.05), but after in vitro digestion, T1 and T2 presented the highest ACE-inhibition activities (p < 0.05) and bioaccessibility indexes (p < 0.05). An antimicrobial effect against Bacillus spp. and S. aureus was observed in Lactobacillus acidophilus and Lactobacillus helveticus postbiotics. However, L. acidophilus postbiotics did not present an antibacterial effect against E. coli. Such findings highlight the potential of postbiotics as functional ingredients to enhance the antioxidant and ACE-inhibition activities of non-fermented dairy beverages, further adding to their appeal as health-promoting dairy food. Full article

(This article belongs to the Special Issue Fermentation: 10th Anniversary)

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15 pages, 4830 KiB

Open AccessArticle

A Novel Pyrazinone Derivative with Anti-MRSA Activity, Produced by Streptomyces anulatus Isolated from the Rhizosphere of Malus trilobata in Lebanon

by Dany Abi Chahine, Bassel Awada, Ghada Derbaj, Aya Hanna, Antoine Abou Fayad and Mireille Kallassy Awad

Fermentation 2025, 11(4), 222; https://doi.org/10.3390/fermentation11040222 - 16 Apr 2025

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Abstract

Antimicrobial resistance (AMR) poses a significant global health threat, largely driven by the overuse and misuse of antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), a multidrug-resistant pathogen, remains a critical target for novel antibiotic development. This study explores the rhizosphere of the wild apple tree [...] Read more.

Antimicrobial resistance (AMR) poses a significant global health threat, largely driven by the overuse and misuse of antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA), a multidrug-resistant pathogen, remains a critical target for novel antibiotic development. This study explores the rhizosphere of the wild apple tree (Malus trilobata) in Lebanon as a potential source of antibacterial compounds. A bacterial strain, MR7S4, identified as Streptomyces anulatus, was isolated and characterized. Its crude extracts exhibited potent activity against Gram-positive pathogens, with minimum inhibitory concentration (MIC) values of 2 µg/mL against S. aureus ATCC 29213, S. aureus Newman, and S. aureus N315 (MRSA), and of 1 µg/mL against Enterococcus faecalis ATCC 19433. Bio-guided fractionation and structural analysis identified a novel antibacterial pyrazinone derivative, MR7S4-F3. This compound demonstrated MIC values of 4–16 µg/mL against Bacillus subtilis ATCC 6633, multiple S. aureus strains, E. faecalis ATCC 19433, E. faecium DSM 17050 (VRE), and E. faecium DSM 20478, while exhibiting no activity against Gram-negative bacteria. Whole-genome sequencing of MR7S4 revealed 35 biosynthetic gene clusters, underscoring its potential for natural product discovery. These findings highlight the untapped microbial diversity of the Middle East and North Africa (MENA) region as a valuable reservoir for antibiotic discovery. MR7S4-F3 emerges as a promising bioactive scaffold, addressing the urgent need for new therapeutic options to combat AMR. Full article

(This article belongs to the Special Issue Antimicrobial Metabolites: Production, Analysis and Application)

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26 pages, 1791 KiB

Open AccessArticle

Microbial Dynamics and Quality Evolution in the Spontaneous Fermentation of the Traditional Meat Product Sjenica Sheep Stelja

by Tanja Žugić Petrović, Vladimir M. Tomović, Sunčića Kocić-Tanackov, Katarina G. Marković, Nataša Joković, Ivana D. Radojević and Mirjana Ž. Grujović

Fermentation 2025, 11(4), 221; https://doi.org/10.3390/fermentation11040221 - 16 Apr 2025

Viewed by 249

Abstract

The Sjenica sheep stelja is a characteristic, traditional dry-cured meat product from Serbia with unique and recognizable sensory attributes. The methodology involved examining physicochemical measurements, followed by sensory evaluation and microbiological analyses, over a 120-day ripening period across three years and three different [...] Read more.

The Sjenica sheep stelja is a characteristic, traditional dry-cured meat product from Serbia with unique and recognizable sensory attributes. The methodology involved examining physicochemical measurements, followed by sensory evaluation and microbiological analyses, over a 120-day ripening period across three years and three different villages, as well as the correlation between chemical characteristics and the number of specific groups of bacteria. Results showed consistent quality parameters across producers and production periods, with notable variation in fat, protein, and ash content. Sensory evaluation confirmed that the product met the quality standards outlined in the Elaborate for the Protection of Geographical Indication, with minor differences in color, aroma, chewiness, and taste among samples. The microbiological analysis demonstrated the dynamic nature of microbial communities throughout maturation, including changes in the counts of aerobic mesophilic bacteria, Enterobacteriaceae, Pseudomonadaceae, lactic acid bacteria, and molds. Penicillium species, particularly P. nalgiovense and P. solitum, were consistently identified, while other fungal genera exhibited varying distribution patterns. The correlation analysis highlights the complex influence of chemical parameters on microbial dynamics throughout the aging process. These findings emphasize the influence of traditional production methods, regional variations, and chemical composition on the sensory quality and microbial safety of Sjenica Sheep Stelja, providing valuable insights for future research and quality control. Full article

(This article belongs to the Topic Fermented Food: Health and Benefit)

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17 pages, 3587 KiB

Open AccessArticle

Enhanced Glutathione Production in Saccharomyces cerevisiae by High-Throughput Screening System Based on Atmospheric and Room Temperature Plasma (ARTP) Mutagenesis

by Lan Li, Zejian Wang, Ali Mohsin and Yingping Zhuang

Fermentation 2025, 11(4), 220; https://doi.org/10.3390/fermentation11040220 - 15 Apr 2025

Viewed by 217

Abstract

In this study, we established a mutagenesis and high-throughput screening system to select a high-yielding glutathione (GSH)-producing strain of Saccharomyces cerevisiae. The parent strain was mutated by atmospheric and room temperature plasma (ARTP) technology and cultivated using ethionine plate cultivation. Subsequently, high-throughput [...] Read more.

In this study, we established a mutagenesis and high-throughput screening system to select a high-yielding glutathione (GSH)-producing strain of Saccharomyces cerevisiae. The parent strain was mutated by atmospheric and room temperature plasma (ARTP) technology and cultivated using ethionine plate cultivation. Subsequently, high-throughput screening was performed using liquid deep microtiter plates (MTPs) for cultivation and a microplate reader for rapid GSH detection. The results demonstrated the successful selection of a stable mutant strain, S-272, which exhibited significantly enhanced GSH production. Fermentation validation in 5 L bioreactors revealed that S-272 achieved a 14.7% higher final GSH concentration and a 19.5% higher intracellular GSH content compared to the parent strain. The improved performance of S-272 was attributed to enhanced ethanol utilization, elevated activity of γ-glutamylcysteine synthetase (γ-GCS), and increased intracellular trehalose content. This study presents an effective strategy for developing high GSH-yield strains using ARTP complex mutagenesis technology combined with high-throughput screening. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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14 pages, 1091 KiB

Open AccessReview

Electro-Fermentation for Biofuel and Biochemical Production

by Priya Pilania, Keshani Bhushan and Urmila Gupta Phutela

Fermentation 2025, 11(4), 219; https://doi.org/10.3390/fermentation11040219 - 15 Apr 2025

Viewed by 183

Abstract

Electro-fermentation (EF) is an emerging bioprocess with the ability to regulate the metabolism of electrochemically active microorganisms. In various fermentation processes, electrodes perform either as an electron acceptor or donor, facilitating the formation and movement of electrons and protons. The bioelectric activity created [...] Read more.

Electro-fermentation (EF) is an emerging bioprocess with the ability to regulate the metabolism of electrochemically active microorganisms. In various fermentation processes, electrodes perform either as an electron acceptor or donor, facilitating the formation and movement of electrons and protons. The bioelectric activity created by external electrodes enhances the metabolic reactions, resulting in a higher yield of value-added chemicals. The conventional fermentation process has a number of limitations in terms of usability and economic feasibility, whereas electro-fermentation presents a hybrid technology, minimizing redox instabilities and enhancing the metabolic process in general to achieve increased product production and a higher biomass yield. Electrochemically active microorganisms such as Geobacter and Shewanella species can carry out the exchange of electrons with electrodes directly or indirectly by using electron mediators. Furthermore, the integration of microbial fuel cells (MFCs) with microbial electrolysis cells (MECs) precludes the need for external manipulation of the fermentation system as the required change in electrochemical gradient is provided by the MFC counterpart. The major beneficial aspects of electro-fermentation include its role as a potential tool for enhancing the production of value-added compounds. The mixed-culture system clearly had a favorable impact on the synthesis of butyric acid from rice straw. Furthermore, cathodic electro-fermentation (CEF) exhibited benefits over anaerobic fermentation, influencing NADH/NAD⁺, enabling a higher product titer, and reducing the accumulation of byproducts. Hence, in this review, we emphasize the importance of electro-fermentation over conventional fermentation for biofuel and biochemical production, covering its fundamentals, interactions, types, future challenges, and ability to provide several benefits to boost the fermentation process, such as the process efficiency and product yield, on an industrial scale. Full article

(This article belongs to the Special Issue Microbial Fuel Cell Advances)

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13 pages, 1704 KiB

Open AccessArticle

Physicochemical and Sensory Properties of Short-Term Fermented Cream Cheese with Added Citrus junos Peel Powder

by Yeon-Su Jeong and Sin-Young Park

Fermentation 2025, 11(4), 218; https://doi.org/10.3390/fermentation11040218 - 15 Apr 2025

Viewed by 174

Abstract

In this study, we analyzed the quality characteristics of short-term fermented cream cheese with added Citrus junos peel (CP). Samples were classified as CP1, CP2, and CP3 based on the amount of CP added. The quality analysis included pH, viscosity, CIE color, electronic [...] Read more.

In this study, we analyzed the quality characteristics of short-term fermented cream cheese with added Citrus junos peel (CP). Samples were classified as CP1, CP2, and CP3 based on the amount of CP added. The quality analysis included pH, viscosity, CIE color, electronic nose, electronic tongue, and sensory evaluation. The pH of the samples significantly decreased with increasing CP levels (p < 0.05). Over time, the viscosity of the CP-added treatment groups was lower than that of the control (Con). The lightness (L* value) of CP-containing samples was significantly lower than that of the Con (p < 0.05). The redness (a* value) of the CP3 sample was significantly higher than that of the other samples (p < 0.05), while the yellowness (b* value) significantly increased with higher CP levels (p < 0.05). Electronic nose analysis indicated that increasing CP content enhanced fruity, apple, orange, sweet, and citrus flavor profiles. Electronic tongue analysis showed that as CP addition increased, saltiness increased, whereas sourness and umami taste decreased. Sensory evaluation revealed that CP1 received high scores in all attributes except “saltiness”, while CP3 received lower scores across evaluations except “saltiness”. In particular, CP1 received significantly higher evaluations in the “off-flavor”, “taste”, “acidity”, and “overall acceptability” evaluations (p < 0.05). Overall, the findings suggested that CP is suitable for use in short-term fermented cream cheese, with CP1 identified as the optimal addition level. Full article

(This article belongs to the Special Issue Trends in the Development and Use of Fermented Dairy Products, 3rd Edition)

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24 pages, 1225 KiB

Open AccessReview

Recent Biotechnological Applications of Whey: Review and Perspectives

by Raúl J. Delgado-Macuil, Beatriz Perez-Armendariz, Gabriel Abraham Cardoso-Ugarte, Shirlley E. Martinez Tolibia and Alfredo C. Benítez-Rojas

Fermentation 2025, 11(4), 217; https://doi.org/10.3390/fermentation11040217 - 15 Apr 2025

Viewed by 276

Abstract

This paper comprehensively reviews whey, a by-product of cheese production, as a raw material for various biotechnological applications. It addresses its unique composition, the environmental impact of its inadequate disposal, and the opportunities it offers to develop high-value products in line with circular [...] Read more.

This paper comprehensively reviews whey, a by-product of cheese production, as a raw material for various biotechnological applications. It addresses its unique composition, the environmental impact of its inadequate disposal, and the opportunities it offers to develop high-value products in line with circular economy and sustainability principles. Using the PRISMA methodology, a systematic search was conducted in various databases (Science Direct, Scopus, and Google Scholar) with specific inclusion and exclusion criteria. Studies from the last five years were considered, focusing on food applications, the production of bioproducts (such as lactic acid, biopolymers, bioethanol, biomass, and enzymes), and the use of whey as a culture medium for the expression of recombinant proteins. It is concluded that the use of whey in biotechnological applications mitigates the environmental impact associated with its disposal and represents an economic and sustainable alternative for the industrial production of bioproducts. The integration of pretreatment technologies, experimental designs, and improvements in producing strains brings these processes closer to competitive conditions in the industry, opening new perspectives for innovation in the fermentation sector. Full article

(This article belongs to the Special Issue Trends in the Development and Use of Fermented Dairy Products, 3rd Edition)

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16 pages, 1322 KiB

Open AccessArticle

Exploring the Influence of Light Wavelength Ranges and Nutrients Reduced Availability’s Impacts on Polyhydroxyalkanoates Accumulation in Purple Phototrophic Bacteria

by Safae Sali, Gordon McKay and Hamish R. Mackey

Fermentation 2025, 11(4), 216; https://doi.org/10.3390/fermentation11040216 - 15 Apr 2025

Viewed by 153

Abstract

Purple phototrophic bacteria (PPB) offer a sustainable approach for biological wastewater treatment while simultaneously producing valuable by-products such as polyhydroxyalkanoates (PHAs). This study investigates the effects of continuous light wavelengths over a two-stage nutrient reduction setup on PHA accumulation in a mixed PPB [...] Read more.

Purple phototrophic bacteria (PPB) offer a sustainable approach for biological wastewater treatment while simultaneously producing valuable by-products such as polyhydroxyalkanoates (PHAs). This study investigates the effects of continuous light wavelengths over a two-stage nutrient reduction setup on PHA accumulation in a mixed PPB culture grown on fuel synthesis wastewater (FSW). The first stage promoted biomass production under nutrient availability, while the second stage targeted the enhancement of PHA accumulation through nitrogen (N) or phosphorus (P) reduction. Biomass growth remained stable under P reduction but significantly increased under N reduction. The results showed that organics removal efficiency decreased under nutrient reduction, particularly under P reduction, while N reduction conditions enhanced P uptake from the media. Maximum PHA accumulation reached 12.6% CDW under N reduction and 10.0% CDW under P reduction. Light type played a dominant role, with a full-spectrum light that included ultraviolet (UV) and infrared (IR) promoting the highest PHA accumulation, whereas white light with far-red wavelengths (700–770 nm) enhanced biomass growth. These findings highlight the potential of optimizing light conditions and nutrient availability to enhance PHA biosynthesis, paving the way for improved bioplastic production from wastewater streams. Full article

(This article belongs to the Special Issue Microbial Production of Polyhydroxyalkanoates (PHAs))

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20 pages, 5467 KiB

Open AccessArticle

Preliminary Study on the Application of Protease-Producing Lactiplantibacillus plantarum in Yogurt Fermentation

by Jing Huang, Jiao Chen and Xiaohui Li

Fermentation 2025, 11(4), 215; https://doi.org/10.3390/fermentation11040215 - 15 Apr 2025

Viewed by 212

Abstract

Starter culture significantly influences the texture and flavor of yogurt, making the selection of appropriate fermentation strains a key focus in yogurt starter research. In this study, protease-producing Lactiplantibacillus plantarum NH-24, identified in prior experiments, was combined with Lactobacillus delbrueckii subsp. bulgaricus and [...] Read more.

Starter culture significantly influences the texture and flavor of yogurt, making the selection of appropriate fermentation strains a key focus in yogurt starter research. In this study, protease-producing Lactiplantibacillus plantarum NH-24, identified in prior experiments, was combined with Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophiles for yogurt fermentation. Indicators such as coagulation state, acidity, and water-holding capacity were measured to determine the optimal fermentation temperature and starter ratio. Additionally, the effects of this strain on the yogurt’s texture, sensory properties, and volatile flavor compounds were evaluated. The results indicate that a fermentation temperature of 37 °C and a starter ratio of 4:4:3 were most suitable for yogurt production. Further analysis demonstrated that incorporating Lp. plantarum NH-24 improved the yogurt’s texture and flavor while reducing post-acidification during storage. Thus, protease-producing Lp. plantarum NH-24 holds significant promise as a yogurt starter culture. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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13 pages, 2715 KiB

Open AccessArticle

Retinal Production by Precision Fermentation of Saccharomyces cerevisiae

by Hye-Seon Hwang, Kwang-Rim Baek and Seung-Oh Seo

Fermentation 2025, 11(4), 214; https://doi.org/10.3390/fermentation11040214 - 14 Apr 2025

Viewed by 236

Abstract

Retinoids, including retinol, retinal, and retinoic acid, are a group of vitamin A derivatives with skin-improving effects. Retinoic acid is highly effective for skin anti-aging but can cause irritation, requiring a prescription. Retinol, a less irritating alternative, needs conversion to retinal and then [...] Read more.

Retinoids, including retinol, retinal, and retinoic acid, are a group of vitamin A derivatives with skin-improving effects. Retinoic acid is highly effective for skin anti-aging but can cause irritation, requiring a prescription. Retinol, a less irritating alternative, needs conversion to retinal and then retinoic acid in the skin, whereas direct absorption of retinal enhances efficacy by bypassing this conversion process. This study aimed to produce retinal through precision fermentation using metabolically engineered Saccharomyces cerevisiae. The introduction of heterologous retinal biosynthetic genes and overexpression of the truncated HMG-CoA reductase (tHMG1) and acetyl-CoA acetyltransferase (ERG10) genes in the mevalonate (MVA) pathway increased retinal production up to 10.2 mg/L. At the same time, ethanol was produced as a major byproduct in S. cerevisiae. To address this, a pyruvate decarboxylase (Pdc)-deficient S. cerevisiae strain, incapable of producing ethanol, was employed. Overexpression of ERG10 and tHMG1 in the Pdc-deficient S. cerevisiae harboring the retinal biosynthetic plasmids achieved a retinal production up to 117.4 mg/L in the dodecane layer without ethanol through a two-phase in situ fermentation and extraction. This study demonstrates that eliminating pyruvate decarboxylase activity effectively redirects carbon flux toward retinal biosynthesis in the recombinant S. cerevisiae, offering a promising approach for sustainable retinal production through precision fermentation. Full article

(This article belongs to the Special Issue Fermentation-Driven Biological Structural Modification of Natural Products)

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15 pages, 1331 KiB

Open AccessReview

Regulation and Mechanisms of L-Lactic Acid and D-Lactic Acid Production in Baijiu Brewing: Insights for Flavor Optimization and Industrial Application

by Yabin Zhou and Jin Hua

Fermentation 2025, 11(4), 213; https://doi.org/10.3390/fermentation11040213 - 12 Apr 2025

Viewed by 220

Abstract

L-lactic acid and D-lactic acid are chiral forms of lactic acid that significantly influence the flavor and health-related properties of Baijiu. Their production during brewing is primarily driven by lactic acid bacteria (LAB), with L-lactic acid being favored at higher fermentation temperatures and [...] Read more.

L-lactic acid and D-lactic acid are chiral forms of lactic acid that significantly influence the flavor and health-related properties of Baijiu. Their production during brewing is primarily driven by lactic acid bacteria (LAB), with L-lactic acid being favored at higher fermentation temperatures and by specific high-producing strains, while D-lactic acid predominates at lower temperatures and with limited microbial utilization. Various factors, including fermentation mash composition, microbial communities, and brewing conditions, affect the balance between these isomers. This review synthesizes recent research on regulating L- and D-lactic acid production in Baijiu brewing, highlighting advancements in raw material selection, fermentation starter composition, temperature control, LAB strain selection, and distillation techniques. It critically evaluates strategies aimed at increasing L-lactic acid content while minimizing D-lactic acid levels to optimize flavor and promote health benefits. This review aims to provide theoretical insights and practical guidance for controlling these chiral isomers in Baijiu production. By consolidating the latest findings, it serves as a resource for industrial applications, offering strategies to enhance lactic acid ratios, improve Baijiu flavor, and support sustainable development in the industry. Full article

(This article belongs to the Special Issue Feature Review Papers in Fermentation for Food and Beverages 2024)

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16 pages, 1956 KiB

Open AccessArticle

Enhancing Antioxidant Activity and Modulating Gut Microbiota Through Lactiplantibacillus plantarum-Fermented Processing Wastewater of Yuba (FPWY)

by Ting Wu, Feiting Hu, Shuxin Tang, Xiaoyun Xu and Duo Li

Fermentation 2025, 11(4), 212; https://doi.org/10.3390/fermentation11040212 - 12 Apr 2025

Viewed by 254

Abstract

Processing wastewater of yuba (PWY), a by-product of yuba production, contains valuable bioactive compounds such as soy isoflavones. However, its utilization remains limited. This study investigated the effects of Lactiplantibacillus plantarum fermentation on the bioactivity of PWY, focusing on its antioxidant properties and [...] Read more.

Processing wastewater of yuba (PWY), a by-product of yuba production, contains valuable bioactive compounds such as soy isoflavones. However, its utilization remains limited. This study investigated the effects of Lactiplantibacillus plantarum fermentation on the bioactivity of PWY, focusing on its antioxidant properties and gut microbiota modulation. The fermentation resulted in a significantly increased amount of free flavonoids from 63.62 μg/mL to 145.91 μg/mL, and transformed glycosylated isoflavones into their more bioavailable aglycone forms. FPWY exhibited stronger antioxidant activity than non-fermented PWY (NFPWY) as indicated by DPPH, ABTS, and FRAP assays. Furthermore, FPWY promoted the growth of beneficial gut bacteria, including Bifidobacterium, Akkermansia, Ruminococcus, and butyrate bacteria, while inhibiting Escherichia coli. FPWY also enhanced the production of short-chain fatty acids (SCFAs), with propionic acid increasing from 5.01 to 9.30 mmol/L and butyric acid increasing from 0.11 to 2.54 mmol/L. These findings suggest that FPWY has a beneficial effect in relation to gut health and oxidative stress. Full article

(This article belongs to the Special Issue The Health-Boosting Power of Fermented Foods and Their By-Products)

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19 pages, 2259 KiB

Open AccessArticle

Amylase Production by the New Strains of Kocuria rosea and Micrococcus endophyticus Isolated from Soil in the Guassa Community Conservation Area

by Seong-Hoon Kim, Woon-Ji Kim, Jaihyunk Ryu, Yeshareg Yerefu and Asmamaw Tesfaw

Fermentation 2025, 11(4), 211; https://doi.org/10.3390/fermentation11040211 - 11 Apr 2025

Viewed by 487

Abstract

Amylases facilitate the hydrolysis of starch into simpler sugars, thus playing a significant role in various industrial applications. This study aimed to isolate and characterize bacteria capable of producing amylase from soil samples collected from the Guassa Community Conservation Area (GCCA), Ethiopia. Comprehensive [...] Read more.

Amylases facilitate the hydrolysis of starch into simpler sugars, thus playing a significant role in various industrial applications. This study aimed to isolate and characterize bacteria capable of producing amylase from soil samples collected from the Guassa Community Conservation Area (GCCA), Ethiopia. Comprehensive biochemical and morphological characterizations were performed on strains isolated from GCCA soil, followed by the optimization of amylase activity. Among the isolates, Kocuria rosea and Micrococcus endophyticus emerged as promising candidates because of their pronounced amylase activity. K. rosea exhibited a clear hydrolysis zone of 15 mm, while M. endophyticus demonstrated a zone of 20 mm, reflecting their efficiency in starch degradation. These two strains achieved optimal growth and produced maximum amylase at a pH of 6–7, temperatures ranging from 30 °C to 40 °C, and an incubation period of 36–72 h. Amylase activity reached its maximum efficiency at temperatures between 45 °C and 55 °C, 0.5 g/L MgCl₂ and CaCl₂, and a pH of 5–7. The amylase of M. endophyticus released 1.505 and 1.421 g/L sugar (highest activity) in acetate and phosphate buffer, respectively. Furthermore, crude amylase extracted from both isolates was used effectively in the dough leavening process, underscoring their applicability in the food industry. This study underscores the potential of K. rosea and M. endophyticus as novel sources of amylases. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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13 pages, 1077 KiB

Open AccessArticle

Synergistic Effect of Microorganisms and Enzymes on Nutritional Value of Corn Stover and Wheat Straw

by Binglong Chen, Jiancheng Liu, Mengjian Liu, Huiling Zhang, Xuanyue Li, Congcong Tian and Yong Chen

Fermentation 2025, 11(4), 210; https://doi.org/10.3390/fermentation11040210 - 10 Apr 2025

Viewed by 303

Abstract

In this study, Candida utilis, Lactobacillus plantarum, and non-starch polysaccharide enzymes (cellulase, laccase, β-glucanase, xylanase, and mannanase) were employed to examine the effects of various microorganism–enzyme combinations on the nutritional composition, fiber structure, and fermentation quality of corn stover and wheat [...] Read more.

In this study, Candida utilis, Lactobacillus plantarum, and non-starch polysaccharide enzymes (cellulase, laccase, β-glucanase, xylanase, and mannanase) were employed to examine the effects of various microorganism–enzyme combinations on the nutritional composition, fiber structure, and fermentation quality of corn stover and wheat straw. Furthermore, the synergistic effects of these treatments were assessed through the use of in vitro rumen fermentation. The results showed that the microorganism–enzyme combinations significantly increased the crude protein content (p < 0.05), while reducing the acid detergent fiber and neutral detergent fiber levels (p < 0.05) in both substrates. The fermentation broth pH decreased (p = 0.06 for corn stover; p < 0.05 for wheat straw) as a result of the treatments, with a significant increase in the lactate concentration (p < 0.05). The reducing sugar levels varied across the treatments (p < 0.05). Mycotoxin analysis revealed trace amounts of zearalenone, well below the Chinese feed hygiene standard. Scanning electron microscopy showed structural modifications, including fiber breakage and surface wrinkling, in the treated substrates. In vitro rumen fermentation demonstrated significant changes in the NH₃-N production and volatile fatty acid profiles (p < 0.05). In conclusion, the addition of different microorganism–enzyme combinations can effectively improve the nutritional composition, fiber structure, and fermentation quality of corn stover and wheat straw. Among the treatments, the T3 group (25% each of C. utilis, L. plantarum, cellulase, and laccase, with a total addition ratio of 0.3% w/w) exhibited the most pronounced improvement in nutritional value for both corn stover and wheat straw. These findings suggest that microorganism–enzyme combinations effectively enhance the nutritional and fermentative quality of agricultural residues. Full article

(This article belongs to the Section Probiotic Strains and Fermentation)

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14 pages, 1691 KiB

Open AccessArticle

Determination of the Optimal Biotechnological Parameters for Industrial Production of Protein Hydrolysates for Animal Feed

by Marina Belyshkina, Tamara Kobozeva, Mikhail Zagoruiko, Oksana Serebryakova, Maisoon Shaaban, Tatiana Ananeva and Igor Bashmakov

Fermentation 2025, 11(4), 209; https://doi.org/10.3390/fermentation11040209 - 10 Apr 2025

Viewed by 256

Abstract

The main disadvantages of using soybean oil extraction waste as a raw feed material are its high contents of fiber, fat, and anti-nutritional factors. Therefore, several processing methods such as extrusion and hydrolysis are used to overcome these disadvantages and increase the availability [...] Read more.

The main disadvantages of using soybean oil extraction waste as a raw feed material are its high contents of fiber, fat, and anti-nutritional factors. Therefore, several processing methods such as extrusion and hydrolysis are used to overcome these disadvantages and increase the availability of high-quality proteins to animals from this by-product. This study is concerned with the hydrolysis of extruded soybean meal in the presence of bacterial alkaline proteases. The effects of various process parameters were investigated to determine the optimal process parameters for hydrolysis in terms of the total free amino acid and amine nitrogen contents. The experiment included two sets of parameters that were selected for comparison: the temperature and pH in ranges of t 45–50 °C, pH 8–11, compared to the temperature and pH ranges of t = 40–45 °C and pH 7–9, using three enzyme/substrate ratios (1:10, 1:20, and 1:30). The protein hydrolysate was stored for three months after it was treated with two different preservatives (sorbic acid and thymol). Based on the results, it was found that the total free amino acid content was higher when the temperature range was 45–50 °C, the pH range was 8–11, and sorbic acid was used as a preservative. Full article

(This article belongs to the Section Industrial Fermentation)

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25 pages, 1691 KiB

Open AccessReview

Microbial Poly-Glutamic Acid: Production, Biosynthesis, Properties, and Their Applications in Food, Environment, and Biomedicals

by Verma Manika, Palanisamy Bruntha Devi, Sanjay Pratap Singh, Geereddy Bhanuprakash Reddy, Digambar Kavitake and Prathapkumar Halady Shetty

Fermentation 2025, 11(4), 208; https://doi.org/10.3390/fermentation11040208 - 10 Apr 2025

Viewed by 357

Abstract

This review offers an in-depth analysis of microbial γ-poly-glutamic acid (γ-PGA), highlighting its production, biosynthetic pathways, unique properties, and extensive applications in the food and health industries. γ-PGA is a naturally occurring biopolymer synthesized by various microorganisms, particularly species of Bacillus. The [...] Read more.

This review offers an in-depth analysis of microbial γ-poly-glutamic acid (γ-PGA), highlighting its production, biosynthetic pathways, unique properties, and extensive applications in the food and health industries. γ-PGA is a naturally occurring biopolymer synthesized by various microorganisms, particularly species of Bacillus. The report delves into the challenges and advancements in cost-effective production strategies, addressing the economic constraints associated with large-scale γ-PGA synthesis. Its biocompatibility, biodegradability, and non-toxic nature make it a promising candidate for diverse industrial applications. γ-PGA’s exceptional water-holding capacity and humectant properties are key to its utility in the food industry. These features enable it to enhance the stability, viscosity, and shelf life of food products, making it a valuable ingredient in processed foods. The review highlights its ability to improve the textural quality of baked goods, stabilize emulsions, and act as a protective agent against staling. Beyond food applications, γ-PGA’s role in health and pharmaceuticals is equally significant. Its use as a drug delivery carrier, vaccine adjuvant, and biofilm inhibitor underscores its potential in advanced healthcare solutions. Full article

(This article belongs to the Special Issue Novel Strategies and Emerging Technologies in Functional and Sustainable Food Systems)

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12 pages, 445 KiB

Open AccessArticle

Development and Production of High-Oleic Palm Oil Alternative by Fermentation of Microalgae

by Leon Parker, Kevin Ward, Thomas Pilarski, James Price, Paul Derkach, Mona Correa, Roberta Miller, Veronica Benites, Dino Athanasiadis, Bryce Doherty, Lucy Edy, Gawharah Alnozaili, Nina Reyes, Jon Wittenberg, Gener Eliares, Frédéric Destaillats, Walter Rakitsky and Scott Franklin

Fermentation 2025, 11(4), 207; https://doi.org/10.3390/fermentation11040207 - 10 Apr 2025

Viewed by 236

Abstract

The development of high-oleic palm oil alternatives through microbial fermentation offers a sustainable solution to the environmental challenges associated with traditional palm oil cultivation. In this study, a Prototheca moriformis microalgae strain was optimized via classical strain improvement techniques to produce a high-oleic [...] Read more.

The development of high-oleic palm oil alternatives through microbial fermentation offers a sustainable solution to the environmental challenges associated with traditional palm oil cultivation. In this study, a Prototheca moriformis microalgae strain was optimized via classical strain improvement techniques to produce a high-oleic palm oil with fatty acid and triacylglycerol (TAG) profiles similar to those of conventional high-oleic palm oil. Iterative rounds of mutagenesis and screening enhanced the palmitic acid content from 28 to 30–32% and oleic acid from 60 to 55–57% of total fatty acids, with an oil yield of 136.5 g/L and an oil content of 69.45% of the dry cell weight. The scalability of this process was demonstrated across fermentation scales ranging from 1 L to 50 L. The TAG profile showed elevated unsaturated TAG species, meeting the quality and nutritional requirements of industrial applications. These findings highlight the potential of microbial systems to address the growing demand for high-value nutritional oils while alleviating the environmental and socio-economic impacts of tropical oil crop cultivation. The application of P. moriformis fermentation provides a transformative approach to advancing sustainability and resilience in global fat and oil production. Full article

(This article belongs to the Special Issue Algae—The Medium of Bioenergy Conversion: 2nd Edition)

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7 pages, 1119 KiB

Open AccessCommunication

Preparing Sponge Dough for Making Bread Using Wheat Flour Cultured in 5% Saline

by Naganori Ohisa, Kazuto Endo and Toshikazu Komoda

Fermentation 2025, 11(4), 206; https://doi.org/10.3390/fermentation11040206 - 10 Apr 2025

Viewed by 221

Abstract

A 5% salt solution was used to make sponge dough from wheat flour. We devised a new starter (wheat flour saline culture) by adding 5% saline to wheat flour and incubating it for 24 h. The dough’s rise was enhanced by adding wheat [...] Read more.

A 5% salt solution was used to make sponge dough from wheat flour. We devised a new starter (wheat flour saline culture) by adding 5% saline to wheat flour and incubating it for 24 h. The dough’s rise was enhanced by adding wheat flour saline culture to the dough: after two hours, the dough volume increased by 20–30% compared to the control. Furthermore, the specific volume of the bread increased from 2.25 cm³/g in the control to 2.73–3.47 cm³/g when sugar or other auxiliary ingredients were not added to it. Wheat flour saline culture contained a large number of halotolerant bacteria. The addition of wheat flour saline culture increased the air bubble size and specific volume of the bread. Full article

(This article belongs to the Special Issue Development and Application of Starter Cultures, 2nd Edition)

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18 pages, 2730 KiB

Open AccessArticle

The Effects of Fermentation Time and the Addition of Blueberry on the Texture Properties and In Vitro Digestion of Whey Protein Gel

by Xian Liu, Yuxian Wang, Yufeng Shao, Qian Yu, Congcong Tang, Wenqiong Wang and Zhangwei He

Fermentation 2025, 11(4), 205; https://doi.org/10.3390/fermentation11040205 - 10 Apr 2025

Viewed by 327

Abstract

The interaction of blueberry and whey protein has strong antioxidant properties and potential antibacterial and anti-aging functions during the fermentation process. In this study, the properties of fermented gels derived from whey protein mixed with blueberry juice were investigated for the production of [...] Read more.

The interaction of blueberry and whey protein has strong antioxidant properties and potential antibacterial and anti-aging functions during the fermentation process. In this study, the properties of fermented gels derived from whey protein mixed with blueberry juice were investigated for the production of probiotic-rich products such as jelly and pudding. The microstructure, water-holding capacity, texture changes, rheological properties, and digestive characteristics of fermented gels were evaluated in vitro. The fermented gels with a mixture of whey protein and blueberry exhibited a honeycomb structure, observed by SEM. The adhesiveness of the gel with a mixture of blueberry and whey protein was the highest at 7.5 h and 8.0 h, respectively. The storage modulus (G′) and loss modulus (G″) of the mixed gels were higher than those of whey protein gels before 6 h of fermentation. When the fermentation time was 8 h, the release of polyphenols, flavonoids, and proteins was fastest and greatest during the digestion of gastric and intestinal fluid ether for the whey protein fermented gel and the mixed fermented gel. The water-holding capacity of the mixed gels was lower than that of the whey protein fermented gels during the fermentation period of 8 h. The viable counts of the mixed fermented gels could reach 10⁷ CFU/mL, which was higher than those of whey protein gels after 6 days of storage. Full article

(This article belongs to the Special Issue Dairy Fermentation, 3rd Edition)

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18 pages, 2571 KiB

Open AccessArticle

Beyond Saccharomyces: Exploring the Bioethanol Potential of Wickerhamomyces anomalus and Diutina rugosa in Xylose and Glucose Co-Fermentation

by Arthur Gasetta Batista, Marcus Vinicius Astolfo da Costa, Marita Vedovelli Cardozo, Sarah Regina Vargas, Marita Gimenez Pereira, Vinícius de Abreu D’Ávila, Janerson José Coelho and Caio Roberto Soares Bragança

Fermentation 2025, 11(4), 204; https://doi.org/10.3390/fermentation11040204 - 9 Apr 2025

Viewed by 317

Abstract

Efficient co-fermentation of glucose and xylose remains a critical hurdle in second-generation bioethanol production. In this study, we evaluated two non-Saccharomyces yeasts—Wickerhamomyces anomalus UEMG-LF-Y2 and Diutina rugosa UEMG-LF-Y4—under mixed-sugar conditions. D. rugosa exhibited superior xylose metabolism and ethanol productivity, achieving a [...] Read more.

Efficient co-fermentation of glucose and xylose remains a critical hurdle in second-generation bioethanol production. In this study, we evaluated two non-Saccharomyces yeasts—Wickerhamomyces anomalus UEMG-LF-Y2 and Diutina rugosa UEMG-LF-Y4—under mixed-sugar conditions. D. rugosa exhibited superior xylose metabolism and ethanol productivity, achieving a maximum volumetric productivity (Q_P) of 0.55 g/L·h in a medium containing 20 g/L glucose and 40 g/L xylose. Its highest ethanol yield (Y_P/S) reached 0.45 g EtOH/g sugar, comparable to results from engineered Saccharomyces cerevisiae strains. By contrast, W. anomalus displayed lower ethanol yields (0.24–0.34 g/g) and greater sensitivity to catabolite repression induced by 2-deoxyglucose (2-DG). Xylose consumption by D. rugosa exceeded 80% in high-xylose media, while W. anomalus left residual xylose under all tested conditions. A strong inverse correlation (r < −0.98) between ethanol accumulation and xylose uptake was observed, especially for W. anomalus, indicating ethanol-induced inhibition as a key challenge. These findings highlight the potential of D. rugosa as a robust non-Saccharomyces platform for lignocellulosic bioethanol processes, whereas W. anomalus may benefit from further metabolic or process optimizations. Future research should address ethanol tolerance, inhibitory byproducts, and large-scale feasibility to fully exploit these strains for second-generation bioethanol production. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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Fermentation, Volume 11, Issue 4 (April 2025) – 74 articles

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