Fermentation

17 pages, 2006 KiB

Open AccessArticle

The Antilisterial Effect of Latilactobacillus sakei CTC494 in Relation to Dry Fermented Sausage Ingredients and Temperature in Meat Simulation Media

by Núria Ferrer-Bustins, Jean Carlos Correia Peres Costa, Fernando Pérez-Rodríguez, Belén Martín, Sara Bover-Cid and Anna Jofré

Fermentation 2024, 10(6), 326; https://doi.org/10.3390/fermentation10060326 - 20 Jun 2024

Viewed by 524

Abstract

Listeria monocytogenes, the causative agent of listeriosis, is a relevant pathogen in dry fermented sausages (DFSs), and the application of antilisterial starter cultures is an effective intervention strategy to control the pathogen during DFS production. The effect of factors in relation to [...] Read more.

Listeria monocytogenes, the causative agent of listeriosis, is a relevant pathogen in dry fermented sausages (DFSs), and the application of antilisterial starter cultures is an effective intervention strategy to control the pathogen during DFS production. The effect of factors in relation to DFS formulation and production, NaCl (0–40 g/L), Mn (0.08–0.32 g/L), glucose (0–40 g/L) and temperature (3–37 °C), on the behaviour of L. monocytogenes when cocultured with Latilactobacillus sakei 23K (non-bacteriocinogenic) and CTC494 (bacteriocinogenic) strains was studied through a central composite design in meat simulation media. L. sakei and L. monocytogenes counts, pH, lactic acid production and bacteriocin activity were determined in mono and coculture. The pH decrease and lactic acid production were highly influenced by glucose, while production of sakacin K by L. sakei CTC494 was observed at moderate (10 and 20 °C), but not at the lowest (3 °C) and highest (37 °C), temperatures. Coculture growth had no effect on the acidification and bacteriocin production but inhibited and inactivated L. monocytogenes when L. sakei 23K entered the early stationary phase and when L. sakei CTC494 produced sakacin K. Optimal conditions for achieving a 5-log units reduction of L. monocytogenes were at 20 °C, 20 g/L of NaCl, 0.20 g/L of Mn and 40 g/L of glucose, those highlighting the importance of considering product formulation and fermentation conditions for bioprotective starter cultures application. Full article

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

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14 pages, 4460 KiB

Open AccessArticle

Pile Cloth Media Filtration for Harvesting Microalgae Used for Wastewater Treatment

by Hermann Velten, Daniel Krahe, Nils Hasport, Thomas Fundneider, Ulrich Grabbe, Linda Knorr and Ulf Theilen

Fermentation 2024, 10(6), 325; https://doi.org/10.3390/fermentation10060325 - 20 Jun 2024

Viewed by 601

Abstract

The harvesting of microalgae biomass cultivated during different processes is still identified as the main driver of biomass production cost. Particularly in the field of wastewater treatment, an energy-efficient and reliable harvesting or separation method is needed to remove microalgae biomass from the [...] Read more.

The harvesting of microalgae biomass cultivated during different processes is still identified as the main driver of biomass production cost. Particularly in the field of wastewater treatment, an energy-efficient and reliable harvesting or separation method is needed to remove microalgae biomass from the wastewater after nutrient assimilation. In this study, the suitability of pile cloth media filtration (PCMF) for microalgae harvesting during wastewater treatment is investigated. A mini plate PCMF was operated over 18 months with three different pile cloth media as part of a pilot-scale wastewater treatment plant incorporating a microalgae treatment step for phosphorus and nitrogen removal. During this time, the removal rates and achievable total suspended solids (TSS) concentration in the effluent were recorded. Differences between the three pile cloth media were noticeable, with TSS concentrations ranging from 9.7 mg·L⁻¹ to 17.7 mg·L⁻¹. The pilot-scale data were used to determine the dimensions of a large-scale PCMF and to estimate its energy demand. This resulted in theoretical energy demands of 7 to 8 Wh·m⁻³ or 37 Wh·kg⁻¹ TSS, considerably lower than the energy demand of other harvesting technologies. Full article

(This article belongs to the Special Issue Algae Biotechnology for Biofuel Production and Bioremediation)

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13 pages, 580 KiB

Open AccessArticle

A Mixture of Prebiotics, Essential Oil Blends, and Onion Peel Did Not Affect Greenhouse Gas Emissions or Nutrient Degradability, but Altered Volatile Fatty Acids Production in Dairy Cows Using Rumen Simulation Technique (RUSITEC)

by Joel O. Alabi, Michael Wuaku, Chika C. Anotaenwere, Deborah O. Okedoyin, Oludotun O. Adelusi, Kelechi A. Ike, DeAndrea Gray, Ahmed E. Kholif, Kiran Subedi and Uchenna Y. Anele

Fermentation 2024, 10(6), 324; https://doi.org/10.3390/fermentation10060324 - 20 Jun 2024

Viewed by 443

Abstract

This study evaluated the synergistic effects of prebiotics containing galacto-oligosaccharides (GOS) and/or mannan oligosaccharides (MOS), essential oil blend (EOB), and onion peel (OPE) on fermentation characteristics using the rumen simulation technique (RUSITEC) system. Three rumen-cannulated, non-lactating Holstein Friesian cows were the inoculum donors. [...] Read more.

This study evaluated the synergistic effects of prebiotics containing galacto-oligosaccharides (GOS) and/or mannan oligosaccharides (MOS), essential oil blend (EOB), and onion peel (OPE) on fermentation characteristics using the rumen simulation technique (RUSITEC) system. Three rumen-cannulated, non-lactating Holstein Friesian cows were the inoculum donors. The substrate used for the study was a total mixed ration (TMR), which consisted of corn silage, alfalfa hay, and concentrate at 6:2:2, respectively. Sixteen fermentation vessels were randomly allotted to four treatments with four replicates each over a 9-day period in a completely randomized design. The treatments assessed include: control [TMR only], GEO [TMR + GOS + EOB + OPE], MEO [TMR + MOS + EOB + OPE], and OLEO [TMR + OLG + EOB + OPE]. OLG comprises GOS and MOS in equal proportion. EOB was included at 3 µL/g, while OPE, GOS, MOS, and OLG were added at 30 mg/g TMR. Results showed that pH, gas volume, effluent volume, and ammonia-N were not affected (p > 0.05) by the different additives. Similarly, greenhouse gas (GHG) emissions and nutrient digestibility were not affected by the treatments. Compared to the control, total volatile fatty acids (VFA) were decreased (p < 0.05) by 14.8, 10.8, and 8.5% with GEO, MEO, and OLEO inclusion, respectively, while the molar proportion of acetate was increased (p = 0.011) by 3.3, 1.1, and 3.8% with GEO, MEO, and OLEO inclusion, respectively. MEO increased isobutyrate (p = 0.001) and branched chain VFA (p = 0.013) contents; however, GEO and OLEO inclusion reduced them. Overall, the interaction of EOB, OPE, GOS, and/or MOS did not affect nutrient digestibility or GHG emissions but reduced VFA production. Further research is recommended to assess the dose effect of the additives on GHG emissions and VFA production; and to determine the long-term effects of these interventions on the rumen microbiome and animal performance. Full article

(This article belongs to the Section Industrial Fermentation)

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19 pages, 2776 KiB

Open AccessArticle

Fed-Batch Bioreactor Cultivation of Bacillus subtilis Using Vegetable Juice as an Alternative Carbon Source for Lipopeptides Production: A Shift towards a Circular Bioeconomy

by Irene Gugel, Maliheh Vahidinasab, Elvio Henrique Benatto Perino, Eric Hiller, Filippo Marchetti, Stefania Costa, Jens Pfannstiel, Philipp Konnerth, Silvia Vertuani, Stefano Manfredini and Rudolf Hausmann

Fermentation 2024, 10(6), 323; https://doi.org/10.3390/fermentation10060323 - 20 Jun 2024

Viewed by 516

Abstract

In a scenario of increasing alarm about food waste due to rapid urbanization, population growth and lifestyle changes, this study aims to explore the valorization of waste from the retail sector as potential substrates for the biotechnological production of biosurfactants. With a perspective [...] Read more.

In a scenario of increasing alarm about food waste due to rapid urbanization, population growth and lifestyle changes, this study aims to explore the valorization of waste from the retail sector as potential substrates for the biotechnological production of biosurfactants. With a perspective of increasingly contributing to the realization of the circular bioeconomy, a vegetable juice, derived from unsold fruits and vegetables, as a carbon source was used to produce lipopeptides such as surfactin and fengycin. The results from the shake flask cultivations revealed that different concentrations of vegetable juice could effectively serve as carbon sources and that the fed-batch bioreactor cultivation strategy allowed the yields of lipopeptides to be significantly increased. In particular, the product/substrate yield of 0.09 g/g for surfactin and 0.85 mg/g for fengycin was obtained with maximum concentrations of 2.77 g/L and 27.53 mg/L after 16 h, respectively. To conclude, this study provides the successful fed-batch cultivation of B. subtilis using waste product as the carbon source to produce secondary metabolites. Therefore, the consumption of agricultural product wastes might be a promising source for producing valuable metabolites which have promising application potential to be used in several fields of biological controls of fungal diseases. Full article

(This article belongs to the Special Issue Use of Agro-Industrial Wastes and By-Products for a Sustainable Production of Eco-Friendly Surface Active Compounds)

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14 pages, 4181 KiB

Open AccessArticle

Pullulan Production from Sugarcane Bagasse Hemicellulosic Hydrolysate by Aureobasidium pullulans ATCC 42023 inBubble Column Reactor

by Rufis Fregue Tiegam Tagne, Mónica María Cruz-Santos, Felipe Antonio Fernandes Antunes, Vinícius Pereira Shibukawa, Sara Barboza Miano, Junie Albine Atangana Kenfack, Silvio Silvério da Silva, Serges Bruno Lemoupi Ngomade and Júlio César Santos

Fermentation 2024, 10(6), 322; https://doi.org/10.3390/fermentation10060322 - 20 Jun 2024

Viewed by 474

Abstract

Due to its unique physicochemical properties, Pullulan is an exopolysaccharide with many applications in the food, biomedical, and pharmaceutical industries. Aiming to reduce its production cost, an interesting alternative is to consider other possibilities of raw materials, including the production of this biopolymer [...] Read more.

Due to its unique physicochemical properties, Pullulan is an exopolysaccharide with many applications in the food, biomedical, and pharmaceutical industries. Aiming to reduce its production cost, an interesting alternative is to consider other possibilities of raw materials, including the production of this biopolymer in a lignocellulosic biorefinery concept. Xylose is the main sugar of hemicellulosic hydrolysates obtained from different biomasses, and it is a sugar still not extensively exploited regarding its potential for pullulan production. This study aimed to evaluate the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate by cultivating Aureobasidium pullulans ATCC 42023 in a bubble column reactor. The hemicellulosic hydrolysate was obtained through dilute acid treatment carried out in a stirred tank reactor before being detoxified to remove microbial growth inhibitors. The maximum concentration of 28.62 ± 1.43 g/L of pullulan was obtained after 120 h of fermentation in a bubble column reactor in batch mode. Analysis of spectroscopic properties through FTIR of the obtained pullulan revealed α-(1→6)-linked maltosyl units, similar to those of commercial samples of the biopolymer. XRD analysis showed that the prepared pullulan is amorphous, and a homogeneous morphology with a smooth surface of the pullulan was observed in SEM analysis. This study showed the potential of the production of pullulan from sugarcane bagasse hemicellulosic hydrolysate in a bubble column bioreactor, an alternative strategy for the industrial production of this biopolymer. Full article

(This article belongs to the Section Industrial Fermentation)

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17 pages, 3071 KiB

Open AccessArticle

Physicochemical Characterization of In Situ Annealed Starch and Its Application in a Fermented Dairy Beverage

by Luma Sarai de Oliveira, Andres David Cordon Cardona, Pedro Henrique Freitas Cardines, Márcio de Barros, Adriana Aparecida Bosso Tomal and Thais de Souza Rocha

Fermentation 2024, 10(6), 321; https://doi.org/10.3390/fermentation10060321 - 18 Jun 2024

Viewed by 422

Abstract

In this study, the aim was to modify the starches of three different sweet potato varieties—Rosada Uruguaiana (RU), Rosada Canadense (RC), and Ligeirinha (L)—through in situ annealing to increase the content of slowly digestible starch (SDS), which has health benefits. The modified carbohydrate [...] Read more.

In this study, the aim was to modify the starches of three different sweet potato varieties—Rosada Uruguaiana (RU), Rosada Canadense (RC), and Ligeirinha (L)—through in situ annealing to increase the content of slowly digestible starch (SDS), which has health benefits. The modified carbohydrate was then added to a dairy beverage fermented by Lactobacillus casei 1e (L. casei). After annealing, the starches had different physicochemical properties, and the L variety, which had the highest SDS content, was chosen for the formulation of the fermented dairy beverage. Two concentrations of modified starch (7% and 10.5%) were used in the formulations, and a sensory analysis indicated no differences in acceptance and purchase intention. The beverage containing 10.5% modified starch exhibited good physicochemical and microbiological stability. This study demonstrates the possibility of creating a functional fermented dairy beverage with high SDS content, which could potentially benefit consumers’ health. Full article

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

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14 pages, 2924 KiB

Open AccessArticle

Improvement in Ethylene Glycol Bioconversion to Glycolic Acid by Gluconobacter oxydans Using Central Composite Experimental Design and Bioreactor Fed-Batch Strategies

by Isabella Maria Tenório Soares Santos, Evanildo F. de Souza, Jr., Ricardo Gonzalo Ramirez Brenes, Maria Angela Bernardes Grieco, Ninoska Isabel Bojorge Ramirez and Nei Pereira, Jr.

Fermentation 2024, 10(6), 320; https://doi.org/10.3390/fermentation10060320 - 18 Jun 2024

Viewed by 554

Abstract

This study focuses on optimizing the medium composition for cellular biomass production and bioconversion of ethylene glycol (EG) to glycolic acid (GA) using Gluconobacter oxydans CCT 0552. The improvement in cellular growth in the presence of yeast extract and peptone led to a [...] Read more.

This study focuses on optimizing the medium composition for cellular biomass production and bioconversion of ethylene glycol (EG) to glycolic acid (GA) using Gluconobacter oxydans CCT 0552. The improvement in cellular growth in the presence of yeast extract and peptone led to a 35.7% and 32.7% increase, respectively, compared to the medium with each of these carbon sources separately. Negligible growth was produced when (NH₄)₂SO₄ and urea were used. Optimal bioconversion results were very similar for both the stirred tank and bubble column bioreactors, with GA concentrations reaching 49.4 g/L and 47.7 g/L, volumetric productivities of 0.35 g/L∙h and 0.33 g/L∙h, and product yield factors of 1.08 g/g and 0.94 g/g, respectively. An extended fed-batch strategy using a STR-type bioreactor achieved a concentration of glycolic acid of 94.2 g/L, corresponding to a volumetric productivity of 0.41 g/L∙h and a yield factor of 1.19 g/g. The resulting efficiency of this biological transformation process achieved a remarkable value of 97.3%, simultaneously with a significant decrease in the substrate amount by 90.5%. This study demonstrates the efficiency of G. oxydans in producing GA, offering a cost-effective and environmentally sustainable production method. Full article

(This article belongs to the Special Issue Recent Advances in Bioconversion of Biomass to Value-Added Products)

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15 pages, 2035 KiB

Open AccessArticle

Metabolic Engineering of Bacillus subtilis for the Production of Poly-γ-Glutamic Acid from Glycerol Feedstock

by Lorenzo Pasotti, Ilaria Massaiu, Paolo Magni and Cinzia Calvio

Fermentation 2024, 10(6), 319; https://doi.org/10.3390/fermentation10060319 - 17 Jun 2024

Viewed by 520

Abstract

Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by Bacilli fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. [...] Read more.

Poly-γ-glutamic acid (γ-PGA) is an attractive biopolymer for medical, agri-food, and environmental applications. Although microbial synthesis by Bacilli fed on waste streams has been widely adopted, the obtainment of efficient sustainable production processes is still under investigation by bioprocess and metabolic engineering approaches. The abundant glycerol-rich waste generated in the biodiesel industry can be used as a carbon source for γ-PGA production. Here, we studied fermentation performance in different engineered Bacillus subtilis strains in glycerol-based media, considering a swrA⁺ degU32^Hy mutant as the initial producer strain and glucose-based media for comparison. Modifications included engineering the biosynthetic pgs operon regulation (replacing its native promoter with P_hyspank), precursor accumulation (sucCD or odhAB deletion), and enhanced glutamate racemization (racE overexpression), predicted as crucial reactions by genome-scale model simulations. All interventions increased productivity in glucose-based media, with P_hyspank-pgs ∆sucCD showing the highest γ-PGA titer (52 g/L). Weaker effects were observed in glycerol-based media: ∆sucCD and P_hyspank-pgs led to slight improvements under low- and high-glutamate conditions, respectively, reaching ~22 g/L γ-PGA (26% increase). No performance decrease was detected by replacing pure glycerol with crude glycerol waste from a biodiesel plant, and by a 30-fold scale-up. These results may be relevant for improving industrial γ-PGA production efficiency and process sustainability using waste feedstock. The performance differences observed between glucose and glycerol media also motivate additional computational and experimental studies to design metabolically optimized strains. Full article

(This article belongs to the Special Issue Biological Conversion of Biomass Residues and Waste Streams for the Sustainable Production of Biofuels and Bio-Based Products: 2nd Edition)

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19 pages, 3818 KiB

Open AccessArticle

Enhancing Freezing Stress Tolerance through Regulation of the Ubiquitin–Proteasome System in Saccharomyces cerevisiae

by Ryoya Tanahashi, Akira Nishimura, Kyoyuki Kan, Natsumi Ishizaki, Shiho Fujishima, Hisanori Endo and Hiroshi Takagi

Fermentation 2024, 10(6), 318; https://doi.org/10.3390/fermentation10060318 - 17 Jun 2024

Viewed by 443

Abstract

The baking industry is experiencing significant growth, primarily due to the widespread adoption of frozen dough baking. However, this process can negatively impact the fermentation ability of yeast, as freezing can induce stress in yeast cells. This study reports the molecular interplay between [...] Read more.

The baking industry is experiencing significant growth, primarily due to the widespread adoption of frozen dough baking. However, this process can negatively impact the fermentation ability of yeast, as freezing can induce stress in yeast cells. This study reports the molecular interplay between the ubiquitin–proteasome system and freezing stress tolerance in the yeast Saccharomyces cerevisiae. Using the proteasome inhibitor MG132, we first screened mutants with enhanced freezing stress tolerance. Three mutants showed elevated activity of the intracellular proteasome, particularly trypsin-like activity (more than threefold) and reduced sensitivity to MG132 inhibition of chymotrypsin-like activity (less than 0.125-fold). Genomic analysis of these mutants revealed mutations in the ROX1 gene, a heme-dependent repressor of hypoxic genes. Importantly, the ROX1 deletion strain displayed slightly improved freezing stress tolerance (about 1.5-fold). Comprehensive transcription analysis identified the ANB1 gene as a potential downstream target of Rox1. Overexpression of ANB1 enhanced freezing stress tolerance (about 1.5-fold) with increased the proteasome’s activity, indicating that Rox1 contributes to changes in the proteasome’s activity and freezing stress tolerance through the function of Anb1. The present data provide new insights into the mechanisms of freezing stress tolerance and help us improve the baking of frozen dough to produce higher-quality bread. Full article

(This article belongs to the Special Issue Advances in Beverages, Food, Yeast and Brewing Research, 3rd Edition)

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18 pages, 8740 KiB

Open AccessArticle

The Effect of Different Medium Compositions and LAB Strains on Fermentation Volatile Organic Compounds (VOCs) Analysed by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS)

by Sarathadevi Rajendran, Iuliia Khomenko, Patrick Silcock, Emanuela Betta, Michele Pedrotti, Franco Biasioli and Phil Bremer

Fermentation 2024, 10(6), 317; https://doi.org/10.3390/fermentation10060317 - 15 Jun 2024

Viewed by 866

Abstract

Lactic acid bacteria (LAB) fermentation is a viable approach for producing plant-based flavour compounds; however, little is understood about the impact of different LAB strains and medium compositions on the production of volatile organic compounds (VOCs). This study investigated the impact of the [...] Read more.

Lactic acid bacteria (LAB) fermentation is a viable approach for producing plant-based flavour compounds; however, little is understood about the impact of different LAB strains and medium compositions on the production of volatile organic compounds (VOCs). This study investigated the impact of the addition of individual amino acids (AAs) (L-leucine, L-isoleucine, L-phenylalanine, L-glutamic acid, L-aspartic acid, L-threonine, or L-methionine) to a defined medium (DM) on the generation of VOCs (after 0, 7, and 14 days) by one of three LAB strains (Levilactobacillus brevis WLP672 (LB672), Lactiplantibacillus plantarum LP100 (LP100), and Pediococcus pentosaceus PP100 (PP100)), using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS). The concentration of m/z 45.031 (t.i. acetaldehyde) was significantly (p < 0.05) higher after 7 days of fermentation by LP100 in the DM supplemented with threonine compared to all other media fermented by all three strains. The concentrations of m/z 49.012 (t.i. methanethiol) and m/z 95.000 (t.i. dimethyl disulfide) were significantly (p < 0.05) higher after 7 days of fermentation by either LP100, PP100, or LB672 in the DM supplemented with methionine compared to all other media. Information on the role of individual AAs on VOCs generation by different LAB strains will help to guide flavour development from the fermentation of plant-based substrates. Full article

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

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31 pages, 9619 KiB

Open AccessReview

Bacterial Nanocellulose Produced by Cost-Effective and Sustainable Methods and Its Applications: A Review

by Siriporn Taokaew

Fermentation 2024, 10(6), 316; https://doi.org/10.3390/fermentation10060316 - 14 Jun 2024

Viewed by 1178

Abstract

This review discusses the recent advancements in cost-effective fermentation methods for producing bacterial nanocellulose (BC) from food and agro-industrial waste. Achieving economical cell culture media is crucial for large-scale BC production, requiring nutrient-rich media at low cost to maximize cellulose yield. Various pretreatment [...] Read more.

This review discusses the recent advancements in cost-effective fermentation methods for producing bacterial nanocellulose (BC) from food and agro-industrial waste. Achieving economical cell culture media is crucial for large-scale BC production, requiring nutrient-rich media at low cost to maximize cellulose yield. Various pretreatment methods, including chemical, physical, and biological approaches, are stated to break down waste into accessible molecules for cellulose-producing bacteria. Additionally, strategies such as dynamic bioreactors and genetic engineering methods are investigated to enhance BC production. This review also focuses on the environmental impact assessment and updated application challenges of BC such as medical applications, energy storage/electronics, filtration membranes, and food packaging. By providing insights from the recent literature findings, this review highlights the innovative potential and challenges in economically and efficiently producing BC from waste streams. Full article

(This article belongs to the Special Issue Production of Added-Value Products from Renewable Resources and Engineered Cell Factories)

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27 pages, 1771 KiB

Open AccessReview

Precision Fermentation as an Alternative to Animal Protein, a Review

by Marilia M. Knychala, Larissa A. Boing, Jaciane L. Ienczak, Débora Trichez and Boris U. Stambuk

Fermentation 2024, 10(6), 315; https://doi.org/10.3390/fermentation10060315 - 14 Jun 2024

Viewed by 1401

Abstract

The global food production system faces several challenges, including significant environmental impacts due to traditional agricultural practices. The rising demands of consumers for food products that are safe, healthy, and have animal welfare standards have led to an increased interest in alternative proteins [...] Read more.

The global food production system faces several challenges, including significant environmental impacts due to traditional agricultural practices. The rising demands of consumers for food products that are safe, healthy, and have animal welfare standards have led to an increased interest in alternative proteins and the development of the cellular agriculture field. Within this innovative field, precision fermentation has emerged as a promising technological solution to produce proteins with reduced ecological footprints. This review provides a summary of the environmental impacts related to the current global food production, and explores how precision fermentation can contribute to address these issues. Additionally, we report on the main animal-derived proteins produced by precision fermentation, with a particular focus on those used in the food and nutraceutical industries. The general principles of precision fermentation will be explained, including strain and bioprocess optimization. Examples of efficient recombinant protein production by bacteria and yeasts, such as milk proteins, egg-white proteins, structural and flavoring proteins, will also be addressed, along with case examples of companies producing these recombinant proteins at a commercial scale. Through these examples, we explore how precision fermentation supports sustainable food production and holds the potential for significant innovations in the sector. Full article

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

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12 pages, 633 KiB

Open AccessArticle

Effect of Molasses Addition on the Fermentation Quality and Microbial Community during Mixed Microstorage of Seed Pumpkin Peel Residue and Sunflower Stalks

by Ning Zhang, Yajie Zhou, Adnan Ali, Tengyu Wang, Xinfeng Wang and Xinwen Sun

Fermentation 2024, 10(6), 314; https://doi.org/10.3390/fermentation10060314 - 13 Jun 2024

Viewed by 437

Abstract

This study investigated the effect of molasses addition on the fermentation quality, chemical composition, and bacterial community of seed pumpkin peel residue (SPPR) mixed with sunflower straw (SS) in microstorage feed. Molasses additions on a dry matter basis (DM) were divided into three [...] Read more.

This study investigated the effect of molasses addition on the fermentation quality, chemical composition, and bacterial community of seed pumpkin peel residue (SPPR) mixed with sunflower straw (SS) in microstorage feed. Molasses additions on a dry matter basis (DM) were divided into three groups: 0% control (CON), 1% (MA), and 2% (MB), and the raw materials underwent mixed microstorage for a period of 60 days. MA exhibited the highest content of dry matter (DM), the lowest content of neutral detergent fiber (NDF), acid detergent fiber (ADF), and ammoniacal nitrogen (NH₃-N), as well as the lowest microbial diversity abundance and the highest relative abundance of lactobacilli (p < 0.05). MB demonstrated the highest crude protein (CP) content and acetic acid (AA) and propionic acid (PA) concentrations, with the lowest pH. In conclusion, the addition of molasses could enhance the quality of mixed microsilage feeds composed of seeded pumpkin peel pomace (SPPR) and sunflower straw (SS), with the optimal addition of molasses being 1% on a DM basis. Full article

(This article belongs to the Section Industrial Fermentation)

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15 pages, 1885 KiB

Open AccessArticle

Exopolysaccharide Production in Submerged Fermentation of Pleurotus ostreatus under Red and Green Light

by Georgios Bakratsas, Christoforos Tsoumanis, Haralambos Stamatis and Petros Katapodis

Fermentation 2024, 10(6), 313; https://doi.org/10.3390/fermentation10060313 - 13 Jun 2024

Viewed by 554

Abstract

Light controls the developmental, physiological, morphological, and metabolic responses of many fungi. Most fungi respond primarily to blue, red, and green light through their respective photoreceptors. In this study, a screening of different light wavelengths’ effects on submerged Pleurotus ostreatus cultivation in baffled [...] Read more.

Light controls the developmental, physiological, morphological, and metabolic responses of many fungi. Most fungi respond primarily to blue, red, and green light through their respective photoreceptors. In this study, a screening of different light wavelengths’ effects on submerged Pleurotus ostreatus cultivation in baffled flasks was conducted. P. ostreatus growth was not inhibited in all tested conditions, while an equal or higher protein content was observed in comparison with dark conditions. Red and green light favored exopolysaccharide (EPS) production while red and blue light favored intracellular polysaccharide (IPS) production. To focus on EPS production, the effect of red and green light wavelengths on the production of the polysaccharide via submerged cultivation of P. ostreatus LGAM 1123 was tested. Submerged cultivation using red light in baffled flasks resulted in EPS production of 4.1 ± 0.4 g/L and IPS content of 23.1 ± 1.4% of dry weight (dw), while green light resulted in EPS production of 4.1 ± 0.2 g/L and 44.8 ± 5.2% dw IPS content. Similar production levels were achieved in a 3.5 L bioreactor using red light. The EPS produced using red light revealed a polysaccharide with a higher antioxidant activity compared to the polysaccharides produced by green light. In addition, the analysis of the crude polysaccharides has shown differences in biochemical composition. The structural differences and β glucan’s existence in the crude polysaccharides were confirmed by FT-IR analysis. Overall, these polysaccharides could be used in the food industry as they can enhance the functional health-promoting, physicochemical, and sensory properties of food products. Full article

(This article belongs to the Special Issue Innovative Biotechnological Production of Microbial Polysaccharides)

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14 pages, 2498 KiB

Open AccessReview

The Role and Application of Redox Potential in Wine Technology

by Marin Berovic

Fermentation 2024, 10(6), 312; https://doi.org/10.3390/fermentation10060312 - 12 Jun 2024

Viewed by 567

Abstract

In wine technology, the on-line measurement of redox potential is a fast, accurate, and reliable measurement that provides insight into the metabolism of Saccharomyces cerevisiae, its microbial activity, and the oxidation and reduction state of wine, as well as insight into its [...] Read more.

In wine technology, the on-line measurement of redox potential is a fast, accurate, and reliable measurement that provides insight into the metabolism of Saccharomyces cerevisiae, its microbial activity, and the oxidation and reduction state of wine, as well as insight into its quality and stability. The significance of the redox potential measurement and control in wine technology as well as the maintenance and regulation of fermentation redox potential using temperature and carbon dioxide fluxes are discussed. Redox potential levels from Eh 100 to 180 mV are typical for non-oxidized wine that is bottling-ready, while levels of Eh 270 to 460 mV represent oxidized wines with typical failures. The relevance of redox potential measurement during the 2-year maturation of Blau Fränkisch wine in 225 L oak barrels at six levels at a temperature 15 °C is presented. The measurement of the redox potential, expressing heterogeneity in redox layers during wine maturation in oak barrels, is represented in various oxido-reductive fermentation zones. On the contrary, the end of the maturation process is indicated by the homogeneity of redox zones, where the matured wine shows no differences in redox measurement on all levels. Using redox potential as a key scale-up criteria ensures comparable and reproducible amounts of the final product even in geometrically non-similar fermenter systems. Full article

(This article belongs to the Special Issue Modeling, Control and Optimization of Wine Fermentation)

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17 pages, 9433 KiB

Open AccessArticle

Cloning, Expression, Enzymatic Characterization and Mechanistic Studies of M13 Mutant Acetohydroxyacid Synthase That Rescues Valine Feedback Inhibition

by Yaqing Tan, Xingxing Gao, Zhiqiang An, Nan Wang, Yaqian Ma and Hailing Zhang

Fermentation 2024, 10(6), 311; https://doi.org/10.3390/fermentation10060311 - 12 Jun 2024

Viewed by 407

Abstract

Acetohydroxyacid synthase (AHAS) is a key enzyme in the first step of the branched-chain amino acid synthesis pathway, and the production of acetohydroxybutyrate from one molecule of 2-ketobutyric acid and one molecule of pyruvate. AHAS is inhibited by feedback from L-valine, L- [...] Read more.

Acetohydroxyacid synthase (AHAS) is a key enzyme in the first step of the branched-chain amino acid synthesis pathway, and the production of acetohydroxybutyrate from one molecule of 2-ketobutyric acid and one molecule of pyruvate. AHAS is inhibited by feedback from L-valine, L-leucine, and L-isoleucine, and the expression of ilvBN, the gene encoding AHAS, is regulated by all three branched-chain amino acids. A change in amino acids 20–22 on the regulatory subunit (M13 mutation) removes the feedback inhibition by valine. We cloned the gene encoding AHAS (ilvBN) into a vector and then transfected it into Escherichia coli BL21 for expression with targeted changes in amino acids 20–22 on the regulatory subunit, and then determined the activity of the mutated AHAS and its inhibitory effects on valine, isoleucine, and leucine. The enzyme containing the M13 mutation was feedback resistant to all three amino acids. Previous studies have suggested that the binding sites for the three branched-chain amino acids may be at the same variable center. We investigated the enzymatic properties of wild-type and mutant AHAS, modeled their crystal structures, and resolved the mechanism of feedback inhibition induced by mutant M13, which will be useful for continuing the modification of AHAS and the design of broad-spectrum herbicides. Full article

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

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18 pages, 1927 KiB

Open AccessReview

Recent Advances in Resource Utilization of Huangshui from Baijiu Production

by Xiaoying Zhang, Huiwen Zhang, Zhengyi Zhang, Ruixi Wang and Jishi Zhang

Fermentation 2024, 10(6), 310; https://doi.org/10.3390/fermentation10060310 - 12 Jun 2024

Viewed by 544

Abstract

Huangshui is a typical organic wastewater in Chinese Baijiu production, with high pollution and valuable ingredients. Conventional wastewater treatment leads to resource-wasting and environmental pollution. It is urgent that the demand for effective Huangshui treatment with the development of the Baijiu-making industry. This [...] Read more.

Huangshui is a typical organic wastewater in Chinese Baijiu production, with high pollution and valuable ingredients. Conventional wastewater treatment leads to resource-wasting and environmental pollution. It is urgent that the demand for effective Huangshui treatment with the development of the Baijiu-making industry. This review systematically summarizes recent studies, revealing the main characteristics and application of Huangshui, focusing on the application of the rich microbial resources and flavor substances, which provides a practical approach to cascade and full use of Huangshui in medicine, cosmetic, functional food, fertilizer, and wastewater treatment fields. Further research suggested that Huangshui can also be used as an external carbon source for the denitrification system or as an organic liquid water-soluble fertilizer for more fruits and grains. The applications favor improving production efficiency and lowering pollutant emissions and introduce novel concepts for the sustainable development of related industries. Thus, Chinese Baijiu plants can achieve the near-zero emissions of wastewater and cleaner production. Full article

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

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26 pages, 3610 KiB

Open AccessArticle

Exploring Phenotype, Genotype, and the Production of Promising GABA Postbiotics by Lactiplantibacillus plantarum: A Comprehensive Investigation

by Heba Abdel-motaal, Amro Abdelazez, Peikun Wang, Ghada Abady, Shaima Abozaed, Bin Ye, Linan Xu, Yuzhong Zhao, Jianrui Niu, Garsa Alshehry, Eman Algarni, Huda Aljumayi and Xinglin Zhang

Fermentation 2024, 10(6), 309; https://doi.org/10.3390/fermentation10060309 - 11 Jun 2024

Viewed by 758

Abstract

This study aims to investigate the probiotic properties of various isolated strains of Lactiplantibacillus plantarum. Specifically, the focus is on examining the expression of the glutamic acid decarboxylase (GAD) gene and its role in the production of gamma-aminobutyric acid (GABA), a promising [...] Read more.

This study aims to investigate the probiotic properties of various isolated strains of Lactiplantibacillus plantarum. Specifically, the focus is on examining the expression of the glutamic acid decarboxylase (GAD) gene and its role in the production of gamma-aminobutyric acid (GABA), a promising postbiotic metabolite. The investigation includes comprehensive analyses of morphology, genetics, resilience against bile, NaCl, and simulated pancreatin juice (SPJ), carbohydrate fermentation patterns, antibacterial activity, susceptibility to antibiotics, and the presence of β-D-galactosidase and GAD enzymes. Six L. plantarum strains exhibited remarkable resilience against bile, NaCl, and SPJ, as well as susceptibility to antibiotics and antagonistic behavior against pathogens. These strains also showed the presence of β-D-galactosidase. Additionally, five L. plantarum strains were found to harbor the gad gene. Further biochemical analysis of four specific L. plantarum strains revealed promising profiles consisting of antibiotics, vitamins, hormones, and a diverse array of metabolites with potential immunotherapeutic properties. This study highlights the substantial potential of Lactiplantibacillus plantarum in generating beneficial postbiotic metabolites. The identified strains offer exciting avenues for further exploration, with potential applications in functional foods and pharmaceuticals. This research opens up possibilities for harnessing the probiotic and postbiotic potential of L. plantarum to develop novel products with health-promoting properties. Full article

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

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12 pages, 1342 KiB

Open AccessArticle

Amylolytic Capability and Performance of Probiotic Strains in a Controlled Sorghum Fermentation System

by Seth Molamu Rapoo and Mathoto-Lydia Thaoge-Zwane

Fermentation 2024, 10(6), 308; https://doi.org/10.3390/fermentation10060308 - 11 Jun 2024

Viewed by 479

Abstract

This study aimed to explore the fermentative performance of nine lactic acid bacterial strains with probiotic potential during sorghum fermentation. The strain’s attributes including proliferation counts, pH levels, production of organic acid antibacterial activity, and their ability to break down starch were evaluated [...] Read more.

This study aimed to explore the fermentative performance of nine lactic acid bacterial strains with probiotic potential during sorghum fermentation. The strain’s attributes including proliferation counts, pH levels, production of organic acid antibacterial activity, and their ability to break down starch were evaluated during the fermentation period in the presence and absence of glucose as a carbon source. In addition, the inhibitory activity of these potential probiotic strains against pathogenic bacteria (Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus) was examined through a co-culturing technique. The results demonstrated that all 4 Lactobacillus strains exhibited robust growth in both glucose and glucose-free fermentation experiments. Glucose supplementation significantly enhanced lactic acid yield which ranged from 0.19 to 0.44% compared to fermentation without glucose which ranged from 0.04 to 0.29%. The selected Lactobacillus strains effectively lowered the media pH below 4.0 after 24 h, producing substantial lactic acid. Notably, in the absence of glucose, only Lb. helveticus D7 and Lb. amylolyticus D12 achieved pH levels below 4 after 8 h, producing the highest lactic acid amounts of 0.27 and 0.29% after 24 h, respectively. Amylase activity was detected on two strains, D7 and D12. Furthermore, most of the tested Lactobacillus strains demonstrated complete inhibition (6 log to 0 Log CFU/mL) of pathogen growth after 24 h of co-culturing, suggesting their potential for enhancing the safety quality of sorghum-based fermented products. Full article

(This article belongs to the Special Issue Application of Lactic Acid Bacteria in Fermented Food)

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12 pages, 581 KiB

Open AccessArticle

Yeast Culture Is Beneficial for Improving the Rumen Fermentation and Promoting the Growth Performance of Goats in Summer

by Shuang Zhang, Yuancong Geng, Yan Ling, Dan Wang and Guixue Hu

Fermentation 2024, 10(6), 307; https://doi.org/10.3390/fermentation10060307 - 8 Jun 2024

Viewed by 487

Abstract

This study aimed to investigate the effects of yeast cultures on the antioxidant capacity, rumen fermentation, and growth performance of goats in the summer. An in vitro experiment was conducted using yeast culture supplemented at 0% (control), 0.6% (test 1), 0.9% (test 2), [...] Read more.

This study aimed to investigate the effects of yeast cultures on the antioxidant capacity, rumen fermentation, and growth performance of goats in the summer. An in vitro experiment was conducted using yeast culture supplemented at 0% (control), 0.6% (test 1), 0.9% (test 2), and 1.2% (test 3) of the dry matter (DM) weight of the basal diet. With a 24 h fermentation, the pH value; the total short-chain fatty acid, acetic acid, propionic acid, and butyric acid concentrations; and the degradability of the DM, the neutral detergent fiber, and the acid detergent fiber were significantly increased (p < 0.05) in tests 2 and 3 compared with the control group. In the feeding experiment, thirty-six crossbreed goats aged 3.0 ± 0.5 months with a body weight of 11.08 ± 1.41 kg were divided, and the yeast culture was supplemented at 0% (control), 0.90% (test 1), and 1.20% (test 2) of the basal diet. Similar effects on rumen fermentation parameters were obtained in test 1 and 2 groups compared to the in vitro experiment. Moreover, the dry matter intake, average daily gain, serum total antioxidant capacity, and the activities of total superoxide dismutase and glutathione peroxidase were significantly higher and the malondialdehyde concentration was significantly lower (p < 0.05) in tests 1 and 2 compared with the control. The results indicated that yeast culture (0.90%) could improve the antioxidant capacity, rumen fermentation, and growth performance of goats in summer. The optimal supplementation concentration is 0.90% DM. Full article

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

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19 pages, 1409 KiB

Open AccessArticle

Advancing Thermophilic Anaerobic Digestion of Corn Whole Stillage: Lignocellulose Decomposition and Microbial Community Characterization

by Alnour Bokhary, Fuad Ale Enriquez, Richard Garrison and Birgitte Kiaer Ahring

Fermentation 2024, 10(6), 306; https://doi.org/10.3390/fermentation10060306 - 8 Jun 2024

Viewed by 638

Abstract

Converting corn grains into bioethanol is an expanding practice for sustainable fuel production, but this is accompanied by the production of large quantities of by-products such as whole stillage. In the present study, the influence of advanced wet oxidation and steam explosion (AWOEx) [...] Read more.

Converting corn grains into bioethanol is an expanding practice for sustainable fuel production, but this is accompanied by the production of large quantities of by-products such as whole stillage. In the present study, the influence of advanced wet oxidation and steam explosion (AWOEx) pretreatment on biogas production and lignocellulose decomposition of corn whole stillage (CWS) was evaluated using semi-continuous thermophilic reactors. The digestion of the CWS was shown to be feasible with an organic loading rate (OLR) of 1.12 ± 0.03 kg VS/m³ day and a hydraulic retention time (HRT) of 30 days, achieving a methane yield of 0.75 ± 0.05 L CH₄/g VS_fed for untreated stillage and 0.86 ± 0.04 L CH₄/g VS_fed for pretreated stillage, corresponding with an increase in methane yield of about 15%. However, the reactors showed unstable performance with the highest investigated OLRs and shortest HRTs. Under optimal conditions, the conversion efficiencies of COD, cellulose, hemicellulose, and lignin were 88, 95, 97, and 59% for pretreated CWS, and 86, 94, 95, and 51% for untreated CWS, respectively. Microbial community analysis showed that Proteiniphilum, MBA03, and Acetomicrobium were the dominant genera in the digestate and were likely responsible for the conversion of proteins and volatile fatty acids in CWS. Full article

(This article belongs to the Collection Bioconversion of Lignocellulosic Materials to Value-Added Products)

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32 pages, 1794 KiB

Open AccessReview

A Review of the Production of Hyaluronic Acid in the Context of Its Integration into GBAER-Type Biorefineries

by Guadalupe Pérez-Morales, Héctor Mario Poggi-Varaldo, Teresa Ponce-Noyola, Abigail Pérez-Valdespino, Everardo Curiel-Quesada, Juvencio Galíndez-Mayer, Nora Ruiz-Ordaz and Perla Xochitl Sotelo-Navarro

Fermentation 2024, 10(6), 305; https://doi.org/10.3390/fermentation10060305 - 7 Jun 2024

Viewed by 529

Abstract

Biorefineries (BRFs) that process the organic fraction of municipal solid waste and generate bioproducts and bioenergies have attracted attention because they can simultaneously address energy and environmental problems/needs. The objective of this article was to critically review the microbial production of hyaluronic acid [...] Read more.

Biorefineries (BRFs) that process the organic fraction of municipal solid waste and generate bioproducts and bioenergies have attracted attention because they can simultaneously address energy and environmental problems/needs. The objective of this article was to critically review the microbial production of hyaluronic acid (MPHA) and its production profile for its integration into a GBAER-type BRF (a type of BRF based on organic wastes) and to identify the environmental and economic sustainability aspects of the modified BRF that would confirm it as a sustainable option. It was found that the MPHA by selected strains of pathogenic Streptococci was moderate to high, although the trend to work with genetically transformed (GT) (innocuous) bacteria is gaining momentum. For instance, A GT strain of Corynebacterium glutamicum reached a maximum HA production of 71.4 g L⁻¹. MPHA reports that use organic wastes as sources of carbon (C) and nitrogen (N) are scarce. When alternative sources of C and N were used simultaneously, HA production by S. zooepidemicus was lower than that with conventional sources. We identified several knowledge gaps that must be addressed regarding aspects of process scale-up, HA industrial production, economic feasibility and sustainability, and environmental sustainability of the MPHA. Full article

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

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15 pages, 1534 KiB

Open AccessArticle

Naturally Colored Ice Creams Enriched with C-Phycocyanin and Spirulina Residual Biomass: Development of a Fermented, Antioxidant, Tasty and Stable Food Product

by Monize Bürck, Camilly Fratelli, Marcelo Assis and Anna Rafaela Cavalcante Braga

Fermentation 2024, 10(6), 304; https://doi.org/10.3390/fermentation10060304 - 7 Jun 2024

Cited by 1 | Viewed by 735

Abstract

Naturally colored fermented foods currently represent the trend toward a global demand for healthier products. This work produced naturally blue and green ice creams using C-phycocyanin (C-PC) and spirulina residual biomass (RB). The ice creams were assessed based on microbiological analysis, color stability [...] Read more.

Naturally colored fermented foods currently represent the trend toward a global demand for healthier products. This work produced naturally blue and green ice creams using C-phycocyanin (C-PC) and spirulina residual biomass (RB). The ice creams were assessed based on microbiological analysis, color stability over 6 months, antioxidant activity before and after in vitro digestion, and sensory evaluation. Considering the microorganisms that must be analyzed in accordance with Brazilian legislation, no growth was detected during the storage period. L*, a*, and b* were maintained according to the expected colors. The blue color was intoned over the shelf life (SC-PC *b −9.46 to −19.44 and MC-PC *b from −9.87 to −18.04). The antioxidant activity of the fermented ice creams SC-PC and SRB increased from 15.4 to 41.3 and from 15.3 to 38.0 µM TE/g, respectively, after bioaccessibility analysis. The C-PC ice cream’s appearance received the highest rating, with 70.26% of volunteers expressing a strong preference, highlighting its attractiveness. However, there were no significant differences compared to control samples in the global acceptance. The RB ice cream presented lower results for flavor but moderate acceptance. Thus, these fermented ice creams presented color stability over 6 months, and their antioxidant activity increased after in vitro digestion, highlighting their biological potential. Full article

(This article belongs to the Special Issue Production and Purification of Microbial Dyes and Pigments)

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16 pages, 1262 KiB

Open AccessArticle

Assessing the Impact of Commercial Lachancea thermotolerans Immobilized in Biocapsules on Wine Quality: Odor Active Compounds and Organoleptic Properties

by Raquel Muñoz-Castells, Juan Moreno, Teresa García-Martínez, Juan Carlos Mauricio and Jaime Moreno-García

Fermentation 2024, 10(6), 303; https://doi.org/10.3390/fermentation10060303 - 6 Jun 2024

Viewed by 563

Abstract

As a result of climate change, the phenology of grapes has been altered, mainly by increasing the sugar content and decreasing the acidity of ripe grapes. This shift, when the must is fermented, affects the quality of the wine. In this regard, the [...] Read more.

As a result of climate change, the phenology of grapes has been altered, mainly by increasing the sugar content and decreasing the acidity of ripe grapes. This shift, when the must is fermented, affects the quality of the wine. In this regard, the use of selected Saccharomyces and non-Saccharomyces yeasts to mitigate these undesirable effects in wine fermentations entails new strategies to improve their control and also to obtain wines better adapted to current consumer preferences. This work focuses on the use of a commercially available strain of Lachancea thermotolerans immobilized in biological support to form “microbial biocapsules”, comparing its effect with a free format and spontaneous fermentation on alcoholic fermentation and volatile compound composition. These biocapsules, consisting of yeast cells attached to fungal pellets, are being tested to improve wine sensory attributes and also to facilitate yeast inoculation in fermentative and clarification winemaking processes, as well as to reduce time and production costs. The composition of young wines obtained with L. thermotolerans, inoculated as free or biocapsule formats, were compared with those obtained by the traditional method of spontaneous fermentation using native yeast by quantifying 12 oenological variables and the contents in 12 major volatiles, 3 polyols, and 46 minor volatile compounds. The analytical data matrix underwent statistical analysis to compare and establish significant differences at p ≤ 0.05 level between the different wines obtained. Among the major volatiles and polyols, only ethyl acetate, 1,1-diethoxyethane, methanol, 2-methyl-1-butanol, acetoin, ethyl lactate, and glycerol showed significant differences in L. thermotolerans wines. Also, from the minor volatile metabolites, eight showed a significant dependence on the format used for L. thermotolerans, and the other nine volatiles were dependent on both yeast and inoculation format. Only 27 volatiles were selected as aroma-active compounds with odor activity values higher than 0.2 units. Statistical analysis showed a clear separation of the obtained wines into groups when subjected to Principal Component Analysis, and the fingerprinting of wines made with biocapsules shows intermediate values between the two remaining inoculation formats, particularly in the fruity/ripe fruit, green, and floral series. The organoleptic evaluation of wines results in significantly higher values in taste, overall quality, and total score for wines obtained with biocapsules. Full article

(This article belongs to the Special Issue Metabolomics Approaches in Fermented Foods: Unraveling Health Benefits and Enhancing Food Quality)

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20 pages, 2590 KiB

Open AccessArticle

The Correlation between Amino Acids and Biogenic Amines in Wines without Added Sulfur Dioxide

by Sorin Macoviciuc, Marius Niculaua, Constantin-Bogdan Nechita, Bogdan-Ionel Cioroiu and Valeriu V. Cotea

Fermentation 2024, 10(6), 302; https://doi.org/10.3390/fermentation10060302 - 6 Jun 2024

Viewed by 430

Abstract

In classical methods of wine production, amino acids play a critical role, as they are fundamental to all types of fermentation. Beyond their consumption in fermentative processes, amino acids undergo several transformations, such as decarboxylation, which produces biogenic amines. These biogenic amines can [...] Read more.

In classical methods of wine production, amino acids play a critical role, as they are fundamental to all types of fermentation. Beyond their consumption in fermentative processes, amino acids undergo several transformations, such as decarboxylation, which produces biogenic amines. These biogenic amines can increase under certain conditions, such as the presence of spoilage bacteria or during malolactic fermentation. Alternative methods of vinification were applied, using sulfur dioxide as a preservative (+SO₂) and methods without added sulfites. Alternative methods of vinification were applied using sulfur dioxide as a preservative (+SO₂) and methods without added sulfite (−SO₂). Monitoring was conducted for Cabernet Sauvignon red (CS), Cabernet Sauvignon rosé (CSR), Fetească regală still (FR), and Fetească regală frizzante (FRF). Alternative procedures employed the use of Pichia kluyveri for its ability to block the oxidation reactions of grapes, malolactic fermentation for all wines without sulfur dioxide (−SO₂) to ensure superior stability, and the use of several tannin mixtures to avoid oxidation reactions. Correlations were considered between the amino acids and biogenic amines that have a direct relation through decarboxylation or deamination. The pH of the wines, total acidity, and volatile acidity as principal factors of microbiological wine evolution remained constant. The highest mean concentrations of the detected biogenic amines were putrescine at 23.71 ± 4.82 mg/L (CSRSO₂), tyramine at 14.62 ± 1.50 mg/L (FR-SO₂), cadaverine at 4.36 ± 1.19 mg/L (CS-SO₂), histamine at 2.66 ± 2.19 mg/L (FR + SO₂), and spermidine at 9.78 ± 7.19 mg/L (FR + SO₂). The wine conditions ensured the inhibition of decarboxylases, but some correlations were found with the corresponding amino acids such as glutamine (r = −0.885, p < 0.05) (CSR-SO₂), tyrosine (r = −0,858, p < 0.05) (FR-SO₂), lysine (r = −0.906, p < 0.05) (FR-SO₂), and histamine (r = −0.987, p < 0.05) (CSR-SO₂). Multivariate analysis was performed, and no statistical differences were found between samples with (+SO₂) and without added sulfur dioxide (−SO₂). The vinification conditions ensured the wines’ stability and preservation and the conditions of producing biogenic amines at the lowest levels in order to not interfere with the olfactive and gustative characteristics. Full article

(This article belongs to the Special Issue Fermented Beverages Revisited: From Terroir to Customized Functional Products, 2nd Edition)

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7 pages, 202 KiB

Open AccessEditorial

Sustainable Development of Food Waste Biorefineries

by José Luis García-Morales and Francisco Jesús Fernández-Morales

Fermentation 2024, 10(6), 301; https://doi.org/10.3390/fermentation10060301 - 5 Jun 2024

Viewed by 440

Abstract

The sustainable development of food waste biorefineries is crucial for a number of reasons, and these reasons have environmental, economic, and social dimensions [...] Full article

(This article belongs to the Special Issue Sustainable Development of Food Waste Biorefineries)

32 pages, 3519 KiB

Open AccessArticle

Prefeasibility Analysis of Different Anaerobic Digestion Upgrading Pathways Using Organic Kitchen Food Waste as Raw Material

by Tatiana Agudelo-Patiño, Mariana Ortiz-Sánchez and Carlos Ariel Cardona Alzate

Fermentation 2024, 10(6), 300; https://doi.org/10.3390/fermentation10060300 - 5 Jun 2024

Viewed by 498

Abstract

Anaerobic digestion (AD) is a widely applied technology for renewable energy generation using biogas as energy vector. The existing microbial consortium in this technology allows for the use of several types of biomass as substrates. A promising alternative for the production of high-value [...] Read more.

Anaerobic digestion (AD) is a widely applied technology for renewable energy generation using biogas as energy vector. The existing microbial consortium in this technology allows for the use of several types of biomass as substrates. A promising alternative for the production of high-value products (e.g., mixed volatile fatty acids–VFAs, hydrogen) is the use of modified AD. There are several techniques to achieve this objective by modifying the operating conditions of the process. The literature has described the best AD routes for generating renewable energy or high-value products based on specific substrate types and operating conditions. Few studies have reported the integral fraction valorization of the AD process applying the biorefinery concept. This article provides an analysis of the different routes that favor the production of energy carriers and high-value products involving key issues related to operating conditions and substrates. Moreover, AD is addressed through the biorefinery concept. Finally, a case study is presented where renewable energy and mixed VFAs are generated by applying the biorefinery concept in a number of proposed scenarios using organic kitchen food waste (OKFW) as feedstock. The case study involves an experimental and simulation stage. Then, the economic feasibility of the proposed scenarios is evaluated. In conclusion, AD is a promising and economically feasible technology to produce valuable products from several types of waste materials. Full article

(This article belongs to the Special Issue Biogas and Biochemical Production from Anaerobic Digestion)

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30 pages, 713 KiB

Open AccessArticle

Development of Mass-Conserving Atomistic Mathematical Model for Batch Anaerobic Digestion: Framework and Limitations

by Bhushan P. Gandhi, Alfonso José Lag-Brotons, Lawrence I. Ezemonye, Kirk T. Semple and Alastair D. Martin

Fermentation 2024, 10(6), 299; https://doi.org/10.3390/fermentation10060299 - 5 Jun 2024

Viewed by 550

Abstract

A variety of mathematical models have been developed to simulate the biochemical and physico-chemical aspects of the anaerobic digestion (AD) process to treat organic wastes and generate biogas. However, all these models, including the most widely accepted and implemented Anaerobic Digestion Model No.1, [...] Read more.

A variety of mathematical models have been developed to simulate the biochemical and physico-chemical aspects of the anaerobic digestion (AD) process to treat organic wastes and generate biogas. However, all these models, including the most widely accepted and implemented Anaerobic Digestion Model No.1, remain incapable of adequately representing the material balance of AD and are therefore inherently incapable of material conservation. The absence of robust mass conservation constrains reliable estimates of any kinetic parameters being estimated by regression of empirical data. To address this issue, the present work involved the development of a “framework” for a mass-conserving atomistic mathematical model which is capable of mass conservation, with a relative error in the range of machine precision value and an atom balance with a relative error of ±0.02% whilst obeying the Henry’s law and electroneutrality principle. Implementing the model in an Excel spreadsheet, the study calibrated the model using the empirical data derived from batch studies. Although the model shows high fidelity as assessed via inspection, considering several constraints including the drawbacks of the model and implementation platform, the study also provides a non-exhaustive list of limitations and further scope for development. Full article

(This article belongs to the Special Issue Modeling Methods for Fermentation Processes)

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17 pages, 1186 KiB

Open AccessReview

The Impact of Physicochemical Conditions on Lactic Acid Bacteria Survival in Food Products

by Barbara Sionek, Aleksandra Szydłowska, Monika Trząskowska and Danuta Kołożyn-Krajewska

Fermentation 2024, 10(6), 298; https://doi.org/10.3390/fermentation10060298 - 4 Jun 2024

Cited by 1 | Viewed by 607

Abstract

Lactic acid bacteria (LAB), due to their many advantageous features, have been utilized in food manufacturing for centuries. Spontaneous fermentation, in which LAB play a fundamental role, is one of the oldest methods of food preservation. LAB survival and viability in various food [...] Read more.

Lactic acid bacteria (LAB), due to their many advantageous features, have been utilized in food manufacturing for centuries. Spontaneous fermentation, in which LAB play a fundamental role, is one of the oldest methods of food preservation. LAB survival and viability in various food products are of great importance. During technological processes, external physicochemical stressors appear often in combinations. To ensure the survival of LAB, adjustment of optimal physicochemical conditions should be considered. LAB strains should be carefully selected for particular food matrices and the technological processes involved. The LAB’s robustness to different environmental stressors includes different defense mechanisms against stress, including the phenomenon of adaptation, and cross-protection. Recently established positive health effects and influence on human wellbeing have caused LAB to be some of the most desirable microorganisms in the food industry. A good understanding of LAB defense and adaptation mechanisms can lead to both optimization of food production and storage conditions, as well as to obtaining LAB strains with increased tolerance to stressors. Hopefully, as a result, the final food product with naturally present or added LAB can achieve outstanding quality and safety with health benefits that meet consumer expectations. Full article

(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 2nd Edition)

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21 pages, 1323 KiB

Open AccessReview

Molecular Markers and Regulatory Networks in Solventogenic Clostridium Species: Metabolic Engineering Conundrum

by Tinuola Olorunsogbon, Christopher Chukwudi Okonkwo and Thaddeus Chukwuemeka Ezeji

Fermentation 2024, 10(6), 297; https://doi.org/10.3390/fermentation10060297 - 4 Jun 2024

Viewed by 450

Abstract

Solventogenic Clostridium species are important for establishing the sustainable industrial bioproduction of fuels and important chemicals such as acetone and butanol. The inherent versatility of these species in substrate utilization and the range of solvents produced during acetone butanol–ethanol (ABE) fermentation make solventogenic [...] Read more.

Solventogenic Clostridium species are important for establishing the sustainable industrial bioproduction of fuels and important chemicals such as acetone and butanol. The inherent versatility of these species in substrate utilization and the range of solvents produced during acetone butanol–ethanol (ABE) fermentation make solventogenic Clostridium an attractive choice for biotechnological applications such as the production of fuels and chemicals. The functional qualities of these microbes have thus been identified to be related to complex regulatory networks that play essential roles in modulating the metabolism of this group of bacteria. Yet, solventogenic Clostridium species still struggle to consistently achieve butanol concentrations exceeding 20 g/L in batch fermentation, primarily due to the toxic effects of butanol on the culture. Genomes of solventogenic Clostridium species have a relatively greater prevalence of genes that are intricately controlled by various regulatory molecules than most other species. Consequently, the use of genetic or metabolic engineering strategies that do not consider the underlying regulatory mechanisms will not be effective. Several regulatory factors involved in substrate uptake/utilization, sporulation, solvent production, and stress responses (Carbon Catabolite Protein A, Spo0A, AbrB, Rex, CsrA) have been identified and characterized. In this review, the focus is on newly identified regulatory factors in solventogenic Clostridium species, the interaction of these factors with previously identified molecules, and potential implications for substrate utilization, solvent production, and resistance/tolerance to lignocellulose-derived microbial inhibitory compounds. Taken together, this review is anticipated to highlight the challenges impeding the re-industrialization of ABE fermentation, and inspire researchers to generate innovative strategies for overcoming these obstacles. Full article

(This article belongs to the Special Issue Research with Clostridium Species in Biofuel and Biochemical Product Production)

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