Search Results (849)

This study investigated whole-plant maize at three harvest stages: one-third milk line (ML, 1/3 ML), two-thirds ML (2/3 ML), and the mature stage. Two packing densities were applied: 350 kg/m³ (low-density group) and 700 kg/m³ (high-density group). Results showed that starch content increased significantly as the maize matured. The 2/3 ML stage exhibited a 34.0% increase in starch content compared to the 1/3 ML stage (27.96 g/kg dry matter: DM vs. 20.87 g/kg DM, p < 0.01), while the mature stage showed a 13.4% increase compared to the 2/3 ML stage (31.70 g/kg DM vs. 27.96 g/kg DM, p < 0.01). After 60 days of ensiling, DM loss was significantly lower in the high-density group compared to the low-density group (3.37% vs. 9.39%, p < 0.05). From day 7 to day 60 of fermentation, the lactic acid content in the high-density group was consistently higher than in the low-density group by 14.29%, 10.00%, 8.33%, and 9.68%, respectively (p < 0.01). The relative abundance of Clostridium in both groups gradually increased during the first 30 days of fermentation, peaking on day 30 (0.05% in the high-density group vs. 0.12% in the low-density group, p < 0.05), and declined thereafter. On day 30, the abundance of Ruminiclostridium was significantly lower in the high-density group compared to the low-density group (0.12% vs. 0.40%, p < 0.05). Clostridium was negatively correlated with lactic acid bacteria (R² = −0.58, p < 0.01). It also showed negative correlations with pH, lactic acid, and acetic acid (R² = −0.25, −0.23, and −0.09, respectively; p > 0.05), but a positive correlation with ammoniacal nitrogen (R² = 0.28, p > 0.05). In conclusion, the 2/3 ML stage is the optimal harvest time for whole-plant maize. Additionally, a higher packing density can suppress spoilage-associated Clostridium and enhance silage quality. Full article

Chronic kidney disease (CKD) is a progressive disorder that is characterized by the gradual loss of kidney function, often leading to end-stage renal failure. Recent research has highlighted the role of gut dysbiosis and its metabolic byproducts in the pathogenesis of CKD, with a particular focus on short-chain fatty acids (SCFAs). SCFAs, including acetate, propionate, and butyrate, are primarily produced by the fermentation of dietary fibers by the gut microbiota and are known for their systemic anti-inflammatory and immunomodulatory properties. In CKD, gut dysbiosis results in a reduction in SCFA-producing bacteria and an increase in uremic toxin-producing microorganisms, contributing to systemic inflammation, oxidative stress, and renal fibrosis. The depletion of SCFAs has been shown to exacerbate glomerular injury, whereas their presence supports integrity of the glomerular barrier and confers protection against damage. These protective effects are mediated by several mechanisms, including the modulation of immune responses, preservation of epithelial barrier function, and activation of specific receptors, such as G protein-coupled receptor 41 (GPR41), GPR43, and GPR109A. The present review provides a comprehensive overview of current understanding of SCFA-mediated pathways in glomerular protection during CKD progression. It highlights the therapeutic potential of targeting the gut–kidney axis to mitigate CKD progression by examining the complex interplay between gut microbiota and disease development, with a particular focus on strategies to protect the glomerular structure and function. Full article

Sea grape kombucha has been known to exhibit high antioxidant activity due to its elevated total polyphenol content. This study aims to identify and characterize the active microbial community involved in the fermentation of kombucha using sea grapes (C. racemosa) as the primary substrate. Furthermore, it evaluates the effects of different Symbiotic Culture of Bacteria and Yeast (SCOBY) starter concentrations on the physicochemical properties and antioxidant activity of sea grape kombucha. Our results showed that the pH of the kombucha was higher after 7 days of fermentation compared to later time points. The microbial community was composed of 97.08% bacteria and 2.92% eukaryotes, divided into 10 phyla and 69 genera. The dominant genus in all samples was Komagataeibacter. Functional profiling based on 16S rRNA data revealed that metabolic functions accounted for 77.04% of predicted microbial activities during fermentation. The most enriched functional categories were carbohydrate metabolism (15.70%), cofactor and vitamin metabolism (15.54%), and amino acid metabolism (14.24%). At KEGG Level 3, amino acid-associated pathways, particularly alanine, aspartate, and glutamate metabolism (4.24%), were predominant. The fermentation process in sea grape kombucha is primarily driven by carbohydrate and amino acid metabolism, supported by energy-generating and cofactor biosynthesis pathways. Our findings indicate that different metabolic pathways lead to variations in kombucha components, and distinct fermentation stages result in different metabolic reactions. For instance, early fermentation stages (Day 7) are dominated by amino acid metabolism, whereas the late stages (Day 21) show increased activity in carbohydrate and sulfur metabolism. Metabolomic analysis revealed that increasing the SCOBY starter concentration significantly influenced pH, soluble solid content, vitamin C, tannin, and flavonoid content. These variations suggest that fermentation duration and microbial composition significantly influence the spectrum of bioactive metabolites, which synergistically provide functional benefits such as antimicrobial, antioxidant, and metabolic health-promoting activities. For example, sample K1 produced more fatty acids and simple sugar alcohols, sample K2 enriched complex lipid compounds and phytosterols, while sample K3 dominated the production of polyols and terpenoid compounds. Full article

Whole-plant corn silage is a critical feedstuff in global ruminant production, and its nutrient composition is closely tied to harvest timing. As starch acts as the primary energy source in silage-based diets, investigating changes in starch degradation rate provides a theoretical basis for optimizing the efficient utilization of whole-plant corn and its silage in ruminant production. In this study, whole-plant corn (harvested from the milk stage to full ripening stage) and its corresponding silage were used as experimental materials. An in vitro simulated rumen fermentation system was employed to determine the contents of starch, prolamin, amylose, and amylopectin in the samples. The results showed that with delayed harvest time, starch content in both whole-plant corn and its silage increased significantly; prolamin and amylose contents first decreased, then increased; amylopectin content first rose significantly before decreasing; and both starch disappearance rate and speed exhibited a trend of first increasing, then decreasing. After silage fermentation, the silage had significant increases in starch, amylose, and amylopectin contents, and starch disappearance rate; prolamin content decreased; and starch disappearance speed increased extremely significantly. This study indicates that whole-plant corn harvest time and silage fermentation regulate the ruminal starch degradation pattern by altering starch structure, prolamin content, and the proportion of rapidly degradable starch. Full article

The study investigated the effect of adding citrus fruits on the dynamics of reducing sugars during the fermentation of Criollo cocoa beans from Lagunas and Casual (Amazonas, Peru). Both spontaneous fermentations and fermentations supplemented with orange, passion fruit, or pineapple at concentrations of 5% and 10% were conducted over six days in wooden boxes, with samples collected every 24 h. Sucrose, glucose, and fructose contents were quantified using ultra-high-performance liquid chromatography coupled with a refractive index detector (UHPLC-RID), and the data were analyzed via ANOVA and PCA. In samples from Lagunas, initial sucrose levels (69.22 mg/g) decreased sharply during the first two days, whereas in the fermented mass from Casual, the sucrose concentrations were low from the outset (6.3 mg/g). The addition of citrus fruits promoted higher accumulation of glucose and fructose in the intermediate and final stages, reaching maximum concentrations of 76.24 mg/g and 81.06 mg/g, respectively, on day six in Lagunas with 10% fruit supplementation. Multivariate analysis indicated that fruit-treated fermentations exhibited a more active and distinct fermentation profile compared to spontaneous fermentations. These results demonstrate that the controlled addition of citrus fruits represents an innovative, low-cost biotechnological strategy for optimizing cocoa fermentation and may enhance the development of flavor and aroma precursors. Full article

Biohydrogen, a low-carbon footprint technology, can play a significant role in decarbonizing the energy system. It uses existing infrastructure, is easily transportable, and produces no greenhouse gas emissions. Four technologies can be used to produce biohydrogen: photosynthetic biohydrogen, dark fermentation (DF), photo-fermentation, and microbial electrolysis cells (MECs). DF produces more biohydrogen and is flexible with organic substrates, making it a sustainable method of waste repurposing. However, low achievable biohydrogen yields are a common issue. To overcome this, catalytic mechanisms, including enzymatic systems such as [Fe-Fe]- and [Ni-Fe]-hydrogenases in DF and electroactive microbial consortia in MECs, alongside advanced electrode catalysts which collectively surmount thermodynamic and kinetic constraints, and the two stage system, such as DF connection to photo-fermentation and anaerobic digestion (AD) to microbial electrolysis cells (MECs), have been investigated. MECs can generate biohydrogen at better yields by using sugars or organic acids, and combining DF and MEC technologies could improve biohydrogen production. As such, this review highlights the challenges and possible solutions for coupling DF–MEC while also offering knowledge regarding the technical and microbiological aspects. Full article

Traditional sausage in the Republic of Kosovo has been produced for centuries as a traditional method of preserving the nutritional value of meat. In sausage fermentation, natural microbiota such as lactic acid bacteria (LAB) and Micrococcaceae usually participate; these are not only critical for ensuring product safety and flavor development but also represent significant biotechnological potential. The purpose of this study was to analyze traditional fermented sausage, in terms of production practices and hygiene, throughout the production and storage phases. Samples in three stages of production and maturation were analyzed for microbiota, pH, and water activity level. Our results show that the main changes in the bacterial populations from 0 to 7 days of storage included increases in the total numbers of viable mesophilic aerobic bacteria (LAB) and Micrococcaceae (MC). However, the Enterobacteriaceae and coliforms (EC) count showed a significant decrease (p < 0.05) in 1.60 ± 1.62 lg cfu/g by day 14. In conclusion, the number of EC in the traditional sausage was decreased during storage, while LAB and MC were stable, data that indicate the safety and quality of this product. No differences regarding the production practices and storage of traditional sausage were observed, based on the data from the butchers who participated in this study. Full article

Microbial proteins offer a sustainable alternative for animal nutrition. Rossellomorea marisflavi NDS, a bacterium isolated from seawater, was previously identified as a promising candidate due to its high protein content. This study aimed to enhance its single cell protein production through systemic fermentation optimization. Single-factor optimization in shake flask determined the optimal conditions to be: a salinity of 20‰ NaCl, a temperature of 32 °C, and an initial pH of 7.3, and a medium composed of 1% (w/v) corn flour, 1% peptone, 0.3% beef extract, and 0.2% KCl. Scaling up to a 10 L bioreactor demonstrated that a two-stage agitation strategy (150 rpm for the first 20 h followed by 180 rpm for the remaining 12 h) enhanced single cell protein yield. Furthermore, allowing the pH to fluctuate freely was more beneficial for protein production than maintaining a constant pH of 7.3 ± 0.02. Under these optimized conditions, the biomass composition (wet weight) was determined to be 2.3767 ± 0.0205% crude ash, 15.6013 ± 0.0082% crude protein, 0.1023 ± 0.0026% crude lipid, and 2.6997 ± 0.0021% carbohydrates. Amino acid analysis revealed a rich profile, with lysine and glutamic acid being the predominant essential and non-essential amino acids, respectively. Fatty acids analysis indicated that C14:1n5 was the most dominant. These findings underscore the potential of R. marisflavi NDS as a high-quality dietary protein supplement and provide a solid foundation for its industrial-scale production. Full article

Early testicular development is vital for adult male fertility but remains highly vulnerable to stress during the suckling stage. Fermented Chinese chive (Allium tuberosum) is known for its antioxidant and immunomodulatory properties, yet its role in testicular development remains unclear. In this study, Songliao Black piglets received 3‰ fermented Chinese chive (LK group) mixed with starter feed and compared to a control (OD group). Testicular samples at weaning (28 days) underwent transcriptomic and metabolomic analyses. Although no significant differences were observed in gross testicular morphology, the LK group significantly increased individual (13.85%) and litter (15.11%) weaning weights (p < 0.05), with elevated serum triglycerides, total cholesterol, and a 32.2% rise in IgG levels (p < 0.05). Integrated analysis identified 76 shared pathways, including ferroptosis, insulin resistance, PI3K-Akt, MAPK, and cAMP signaling. Upregulated genes in the LK group were mainly related to energy metabolism, antioxidant defense, immune regulation, steroidogenesis, and neuroendocrine signaling, suggesting improved metabolic activity, reduced oxidative stress, and accelerated reproductive maturation. Molecular docking indicated that kaempferol and isorhamnetin from Chinese chive bind strongly to proteins involved in testicular development. Overall, fermented Chinese chive supplementation enhances early testicular development in suckling piglets via integrated modulation of metabolic, immune, and signaling pathways, providing a nutritional strategy to optimize reproductive potential in breeding boars. Full article

Bio-hydrogen and bio-methane co-production was a promising way to enhance the energy conversion efficiency, and enzyme loading and pH are key factors influencing anaerobic fermentation processes. Therefore, in this study, the co-production process of bio-hydrogen and bio-methane was evaluated based on the effect of enzyme loading (20%, 30%, and 40%) combined with initial pH (6.0, 7.0, 8.0, and 9.0). The results indicated that, compared with other conditions, 30% enzyme loading with an initial pH of 8.0 was more feasible for bio-hydrogen and bio-methane co-production from duckweed, achieving a bio-hydrogen yield of 114.56 mL/g total solid (TS) and a bio-methane yield of 260.32 mL/g TS. Under optimum condition, the energy conversion efficiency was 71.4%, which was 6-fold and 4.8-fold higher than that of the single bio-hydrogen production stage (pH 8, 40% and 10.2%) and single methane production stage (control group with 12.30%), respectively. Full article

Fermentation is a crucial stage in the production of washed mild coffees, as it enables the generation of compounds that influence overall quality. The conditions to optimize this process are still unknown. This study evaluated the effects of fermenting coffee fruits and depulped coffee under two conditions: an open tank (semi-anaerobic-SA) and a closed tank (self-induced anaerobic fermentation, SIAF) over 192 h. Samples were taken every 24 h using a sacrificial bioreactor. A randomized complete block design with a factorial arrangement (2 × 2 + 1), plus a standard control, was employed, incorporating two factors: coffee type and fermentation condition. High-throughput sequencing of 16S and ITS amplicons identified an average of 260 ± 71 and 101 ± 24 OTUs, respectively. Weisella was the dominant lactic acid bacteria, followed by Leuconostoc and Lactiplantibacillus. Acetic acid bacteria, mainly Acetobacter, were more abundant under semi-anaerobic conditions. The yeast genera most affected by the fermentation condition were Pichia, Issatchenkia, and Wickerhamomyces. Repeated measures analysis revealed significant differences in pH, glucose consumption, lactic acid production, dry matter content, embryo viability, and the percentage of healthy beans. Principal component analysis was used to develop an index that integrates physical, physiological, and sensory quality variables, thereby clarifying the impact of each treatment. Samples from shorter fermentation times and SIAF conditions scored closest to 1.0, reflecting the most favorable outcomes. Otherwise, samples from longer fermentation times in both depulped and coffee fruits scored 0.497 and 0.369, respectively, on the SA condition. These findings support technically and economically beneficial fermentation strategies. Full article

Microorganisms are crucial for the liquor brewing process and substantially impact liquor flavour and quality; therefore, understanding microbial succession is necessary. Most studies use a single-method approach and fail to provide an in-depth analysis. We aimed to combine traditional culture method with high-throughput sequencing (HTS) to identify the microbial diversity and succession in Luzhou-flavour fermentation. HTS revealed 932 bacterial and 980 fungal operational taxonomic units. 16S rDNA, 26S D1/D2 rDNA, and ITS v4/v5 isolated and identified 256 bacterial and 130 yeast strains. Population succession analysis showed that the dominant populations were yeasts, Lactobacillus, and Bacillus (early stage), and yeasts and Lactobacillus (late stage). Lactobacillus, Pichia, Bacillus, and Candida were abundant among all three layers of fermented grains. However, C. ethanolica, Saccharomycetes sp., and an unidentified Saccharomyces cerevisiae were more abundant in the lower layer than in the middle and upper layers, while L. parabuchneri, Oceanobacillus oncorhynchi, and Thermoactinomyces sp. were present only in the lower layer. Correlations among enzyme activity, volatile production, and dominant microbes during fermentation indicated that P. fermentans, L. suebicus, L. acetotolerans, P. kudriavzevii, P. exigua, and B. tequilensis were significantly affected during brewing. Our results lay a foundation for elucidating the microbial fermentation mechanism of Luzhou-flavour liquor and will assist in improving traditional liquor brewing quality and efficiency. Full article

The growing demand for organic products is having a transformative effect on the alcoholic beverage industry. This work investigates the possibility of producing organic ethanol only from sugarcane final molasses as a nutrient vector and Saccharomyces cerevisiae in the absence of inorganic nitrogen or phosphorus compounds. The Plackett–Bürman design included the pseudo-factors (X4–X6) due to the experimental design requirements. These factors represent the possible influence of uncontrolled variables, such as pH or nutrient interactions. Subsequently, a predictive quadratic model using Box–Behnken design with the real variables (sugar concentration, yeast dose, and incubation time) was developed and validated $(R^2=0.977)$ with internal validation; given the lack of replications and the sample size, this value should be interpreted with caution and not as generalizable predictive evidence. Further experiments with replications and cross-validation will be required to confirm its predictive capacity. Through statistical optimization, the maximum cell proliferation of $432\times {10}^6$ cells/mL was achieved under optimal conditions of 8°Brix sugar concentration, 20 g/L dry yeast, and 3 h incubation time. The optimized fermentation process produced 7.8% v/v ethanol with a theoretical fermentation efficiency of 78.52%, an alcohol-to-substrate yield of 62.15%, and a productivity of 1.86 g/L·h, representing significant improvements of 21.9%, 24.6%, 31.0%, and 10.1%, respectively, compared with non-optimized conditions. The fermentation time was reduced from 48 to 42 h while maintaining superior performance. These results demonstrate the technical feasibility of producing organic ethanol using certified organic molasses and no chemical additives. Overall, these findings should be regarded as proof of concept. All experiments were single-run without biological or technical replicates; consequently, the optimization and models are preliminary and require confirmation with replicated experiments and external validation. Full article

Vanillin is the compound of great interest to the industry. It is used to augment and enhance the aroma and taste of food preparations and also as a fragrance compound in perfumes and detergents. Currently, majority of the world’s supply consists of chemically synthesized or lignin-derived vanillin. The application of biocatalysis for sustainable manufacturing of food ingredients, pharmaceutical intermediates, and fine chemicals is the key concept of modern industrial biotechnology. The main goal of this research was to conduct optimization procedures aimed at intensifying the microbial hydrolysis process of the lignin-rich plant raw materials and further bioconversion of the released ferulic acid to vanillin. The tests were performed in the solid-state fermentation system with strains selected during the screening stage on agri-food by-products such as brewer’s spent grain. A specially designed single-use bag bioreactor was used to carry out the process on a preparative scale with the most effective strain. The experiment was designed using the RSM, which allowed for an increase in biosynthesis efficiency from 363 mg/kg to 1413 mg/kg (an increase of 389%). The progress of the process was controlled by the use of chromatographic techniques (HPLC) by quantitative determination of vanillin content in the obtained extracts. Full article

Potentially probiotic yeasts isolated from foodstuffs can be used as components in functional fermented beverages. To date, there have been no reports on the use of Saccharomyces cerevisiae var. boulardii, Pichia kudriavzevii, Metschnikowia pulcherrima, or Hanseniaspora uvarum isolates in the production of a traditional Polish beverage called underbeer (podpiwek). The aim of the study was to determine the usefulness of six isolates of the above-mentioned species as starter cultures for the fermentation of underbeer. First, the important characteristics of the yeasts, like ethanol tolerance and H₂S production, were examined. In the next stage, the wort was fermented by the tested yeasts, and cell viability, fermentation vigor, sugar assimilation, and production of metabolites, as well as properties of the beverage (pH, titratable acidity, color, and turbidity), were determined. Saccharomyces yeasts tolerated the addition of ethanol up to 16% (v/v), while Pichia, Metschnikowia, and Hanseniaspora tolerated up to 10% (v/v) ethanol, and all except H. uvarum produced H₂S. The yeasts remained viable in the beverages for 1 month at the required level, utilized glucose, fructose and partially complex carbohydrates, and produced ethanol (S. cerevisiae, P. kudriavzevii, and M. pulcherrima) and organic acids such as tartaric, malic, and citric acid. The underbeers became sour and showed varying turbidity and a color corresponding to pale-amber beers. All tested strains produced fermented beverages that were low- or non-alcoholic with different properties. This experiment may be a starting point for research into regional products as probiotic or synbiotic foods; however, further research is required for selection of the best strains for underbeer fermentation. Full article