Search Results (2,979)

This study examined whether co-fermentation with Lactobacillus casei CGMCC 15956 and Lactobacillus delbrueckii CGMCC 21287 could enhance the bioactivity of peptides derived from pecan nut cake (PNC) and clarify the underlying mechanisms. The fermented hydrolysate (PNCH) was compared with an unfermented control. PNCH showed higher antioxidant and α-glucosidase inhibitory activities. Total antioxidant capacity increased from 3.17 to 4.81 mM Trolox, and DPPH radical scavenging activity increased from 62.69% to 84.12%. In addition, the IC₅₀ value for α-glucosidase inhibition decreased from 7.549 to 4.509 mg/mL. In a mouse model of acute alcohol-induced liver injury, PNCH significantly alleviated liver damage through the synergistic enhancement of antioxidant and α-glucosidase inhibitory activities. Peptidomic analysis identified two representative bioactive peptides, FAGDDAPR (from actin) and LAGNPDDEFRPQ (from cupin domain–containing protein 1), both of which exhibited antioxidant and α-glucosidase inhibitory activities. Additionally, these peptides alleviated H₂O₂-induced oxidative stress in Caco-2 cells, significantly improving GSH and MDA levels, as well as SOD activity. Molecular docking suggested potential interactions of these peptides with superoxide dismutase, Keap1, and α-glucosidase. These findings support the high-value utilization of PNC and the development of functional peptide-based ingredients. Full article

Nucleic acids are essential dietary components with diverse physiological functions. Numerous studies have focused on the biological functions of nucleotides, nucleosides, and functional RNAs such as microRNAs. However, the nutritional value of ribosomal RNA (rRNA)-derived oligonucleotides, which are likely the predominant nucleic acid-derived components in foods, remains largely unexplored. Here, yeast was used as a food-associated eukaryotic model organism to investigate the uptake and utilization of rRNA-derived oligonucleotides. Yeast efficiently utilized short RNA oligonucleotides (approximately 5–30 nt) as nutrient sources, supporting robust cell growth. Confocal microscopy confirmed rapid uptake of Cy5-labeled RNA oligonucleotides by yeast cells. Proteomic analysis further revealed marked upregulation of proteins involved in endocytosis and autophagy in yeast cultured with RNA oligonucleotides. Collectively, these findings demonstrate that yeast can internalize and metabolize rRNA-derived oligonucleotides as efficient nutrient sources, likely through coordinated endocytic and autophagic pathways. This study highlights the nutritional potential of rRNA-derived oligonucleotides and provides a foundation for their future application in functional foods and fermentation systems. Full article

This study evaluated the effects of replacing soybean hulls with dried grape pomace (DGP) on feed intake, milk production and composition, and rumen N degradability in dairy cows. A 3 × 3 Latin square design was used with three rumen-fistulated Holstein cows, three corn silage-based diets containing 0%, 3%, or 6% of DGP, and three 23-day periods. Measurements were taken from days 15 to 21, with in situ incubations of two protein sources during the last 2 days. At trial end, cows continued on experimental diets to determine the degradability of soybean hulls and DGP. Compared to soybean hulls, DGP presented higher fiber content and lower in situ rumen dry matter and N degradability. Condensed tannin disappearance from DGP increased over time, reaching almost 50% after 48 h. Diet did not affect feed intake, milk production, and composition, except for milk urea N and ruminal total short-chain fatty acids concentration, which showed a quadratic response, suggesting both imbalances between fermentable energy and rumen degradable protein and potential effects of DGP bioactive compounds on rumen function. The N degradation rate of rapeseed meal was unaffected, but soybean meal degradability tended to increase with higher DGP inclusion. This was also detected when combining protein sources across diets. Although DGP influenced rumen function, further research integrating omics and detailed microbiota profiling is needed. Overall, despite its low energy content and rumen degradability, DGP comprises a sustainable feed resource for high-producing animals, supporting circular economy approaches and mitigating the environmental impacts of grape pomace disposal. Full article

This study explored the patterns and mechanisms influencing changes in silage quality, mycotoxin accumulation, and microbial community structure in oat silage after lodging. Upright oat forage (control, CK), lodging oat forage (upper layer (UL), lower layer (LL), and mixed layers (MLs) were harvested at 0, 7, 25, and 45 days after lodging and ensiled for 60 days. The results showed that the dry matter (DM) and water-soluble carbohydrate (WSC) content decreased significantly (p < 0.05), whereas crude protein (CP) and fiber content increased significantly compared to upright oats (p < 0.05). The WSC and CP content in silage decreased with increasing lodging duration. The fiber content increased in late harvest after lodging. The risk of mycotoxin infection increased after lodging, with aflatoxin levels exceeding EU limits. The mycotoxins in UL silage were the lowest when lodging lasted for seven days. Lodging oat silage was dominated by Lactobacillus, and the Pseudomonas in the lodging group was less than 4%. The fungi in lodging oat silage was lower, and the UL (upper layer) treatment was the lowest when lodging for 7 days. Overall, the transfer of microorganisms, especially Plectosphaerella, Fusarium, Alternaria, Cladosporium, and Botryotrichum, from soil to silage following oat collapse is of interest. The results suggest the soil–plant microbial interactions and their effects on silage fermentation and mycotoxins in lodging oats. Full article

BslA (Biofilm surface layer protein A), a highly hydrophobic lipoprotein from Bacillus spp., self-assembles at fluid interfaces to form a crystalline film that reduces surface tension. In this study, we selected Pichia pastoris as a eukaryotic system for expressing recombinant BslA identified in Bacillus paralicheniformis BL-1. The secretory expression of recombinant BslA in the P. pastoris GS115 strain under the AOX1 promoter was confirmed in shake-flask cultivation. Next, two fed-batch fermentation strategies, constant dissolved oxygen strategy (DO-stat) and oxygen-limited fed-batch (OLFB) strategy, in a 5 L scale, were compared. The DO-stat process led to late-stage cell death and product degradation, limiting yields. Switching to the OLFB process by removing the glycerol feeding phase mitigated this issue, allowing extended fermentation and increasing the final recombinant BslA concentration to 657 mg/L. This study establishes P. pastoris with an OLFB strategy as an effective system for secreting recombinant BslA protein, providing a basis for future industrial-scale production. Full article

Against the backdrop of the global protein crisis and the textural limitations of alternative proteins, microorganisms are increasingly recognized as versatile structural materials to address these challenges. This review systematically analyzes three key microbial strategies: employing mycelial solid-state fermentation to engineer fibrous meat analogues; utilizing bacterial cellulose scaffolds to enhance the texture of both cultured meat and plant-based products; and applying synthetic biology to design tailored functional proteins. Existing studies confirm that mycelial fermentation significantly improves product texture and production sustainability. In parallel, bacterial cellulose provides highly biocompatible nanoscaffolds, while synthetic biology enables the efficient production and nutritional enhancement of complex animal proteins. Although challenges in scaling production and optimizing flavor persist, advanced bioprocess optimization and genetic engineering offer promising solutions. Future breakthroughs are expected to transition from structural mimicry to true functional creation, establish decentralized production networks, and advance dynamic 4D-printed foods, which will collectively contribute to a more sustainable and resilient global food system. Full article

In view of the technical bottleneck of microbial dynamic monitoring during the solid-state fermentation of traditional Baijiu, this study introduced green fluorescent protein (GFP) labeling technology into the dominant Saccharomyces cerevisiae of Jiang-flavored Baijiu to construct the chromosomal integration engineering strain named FSC01. By designing an integrated recombinant plasmid containing the GFP gene and the geneticmycin resistance gene, an engineered strain that stably expresses fluorescent proteins was obtained by electroconversion. Flow cytometry verification showed that FSC01 showed excellent linear responses in the pure microbial system (R² = 0.998) and the complex matrix of Baijiu jiupei (R² = 0.981), with a detection limit of 10² cells/mL, and the detection cycle was shortened to 10 min. Solid-state fermentation simulation experiments show that the inoculation volume of FSC01 of 10⁵ cells/kg can not only ensure the effective identification of fluorescence signals, but also does not significantly interfere with the growth and growth patterns of the original yeast (p > 0.05), which is highly consistent with the results of the traditional plate counting method. Dynamic monitoring shows that Saccharomyces cerevisiae during fermentation presents a typical succession pattern of “increase first and then decrease”, reaching a peak on the 7th day (1.2 × 10⁷ cells/g), which is positively correlated with the base alcohol yield rate (26.7%). Compared with metagenomic (72 h) and PMA-qPCR (4 h) methods, this technology breaks through the limitations of specificity and timeliness of live bacteria detection, and provides a single-cell-level dynamic analysis tool for the digitization of traditional brewing processes. In the future, it will be expanded to monitor key functional microorganisms such as lactic acid bacteria through a multi-color fluorescent labeling system, and optimized pretreatment to eliminate starch granule interference, and promote the in-depth application of synthetic biology technology in the traditional fermentation industry. Full article

This study first adopted a liquid microbial-enzymatic co-fermentation process to enhance the nutritional value of walnut meal (WM) and sesame meal (SM), and systematically evaluated its effect on the nutrient digestibility of growing pigs. WM and SM are two underutilized high-protein by-products, whose application is hindered by anti-nutritional tannin and fiber. Optimal fermentation parameters were determined via single-factor experiments and response surface methodology, utilizing a consortium of Lactobacillus I, Candida utilis, and protease. Fermentation significantly reduced tannin (39.41% in WM) and crude fibre (28.79% in WM), reduced tannin (18.67% in SM) and crude fibre (4.00% in SM), while elevating crude protein (10.63% in WM, 7.47% in SM) and acid-soluble protein in both WM and SM. Results of the microstructure of fermented WM and SM revealed structural loosening, surface porosity, and polysaccharide degradation. Microbial community shifts highlighted the dominance of Lactobacillus and Bacillus in fermented substrates. In growing pigs, fermented WM and SM exhibited improved standardized ileal digestibility (SID) of key amino acids (threonine, tryptophan, valine; p < 0.05), alongside enhanced digestible energy (DE) and metabolizable energy (ME) for SM (p < 0.05). These findings demonstrate that liquid co-fermentation effectively degrades anti-nutritional factors, enhances nutrient bio-availability, and positions WM and SM as viable alternatives to conventional protein sources in swine diets, supporting strategies to reduce reliance on soybean meal. Full article

Although a yeast-based additive was initially employed as a performance enhancer, subsequent analysis revealed high aflatoxin B1 levels in the corn silage. Therefore, the objective of this study is to determine if the use of a yeast blend in the diet of Holstein calves that consumed feed naturally contaminated with high levels of aflatoxin can minimize the negative impacts of mycotoxins on animal health, contributing to improved performance. For this, we used 24 Holstein calves (6 months old) divided into two groups: Control (n = 12; no additive) and Treatment (n = 12; 5 g additive/animal/day). During the 100-day experiment, animals were weighed, feed intake was measured, blood samples were collected to assess health, and ruminal fluid was analyzed for ruminal fermentation. We observed greater weight gain and better feed efficiency in cattle that consumed the yeast-based additive compared to the control group. Yeast ingestion increased the concentration of propionic acid in the experimental environment, as well as increasing the protozoan count. Higher lymphocyte counts combined with higher levels of immunoglobulin G in the blood of females that consumed the additive were observed. Lower activity of enzymes that are biomarkers of liver damage, as well as markers of oxidative stress, was observed when animals consumed the yeast blend compared to the control group. Lower levels of ceruloplasmin (positive acute phase protein) and higher levels of transferrin (negative acute phase protein) are indicative of an anti-inflammatory response to the additive. The results preliminarily suggest that the consumption of the yeast blend is a nutritional tool capable of acting as a performance enhancer, even under challenging conditions, such as diets contaminated with aflatoxin at levels exceeding international limits. Full article

Glycyrrhiza pallidiflora Maxim., a perennial legume with high biomass yield and good nutritional value, has potential as a forage resource. This study examined how mixing G. pallidiflora (C) with Leymus chinensis (Y) at varying ratios (C10Y0, C9Y1, C8Y2, C7Y3, C6Y4) affects silage fermentation, chemical composition, and microbial community structure. All treatments were inoculated with Lactiplantibacillus plantarum (1 × 10⁶ CFU/g fresh weight) and ensiled for 120 days. The results indicated that mixed silages markedly improved overall fermentation quality compared to the sole C silage (C10Y0). These mixed silages exhibited superior lactic acid (LA) concentrations, lower pH. Bacterial community profiling revealed that the addition of Y shifted the microbiota from a diverse community to one dominated by Lactobacillus. Although the C6Y4 and C7Y3 groups exhibited lower pH, they showed significantly elevated NH₃-N contents, while their crude protein contents and the relative abundances of Lactobacillus were both lower than those of the C9Y1 and C8Y2 groups. Considering the core requirements of comprehensive quality, the mixing ratios of 9:1 (C9Y1) and 8:2 (C8Y2) demonstrated the optimal effects: at these ratios, the silage maintained a CP content of 12.84–14.48% DM, with NDF and ADF contents stabilized at 47.55–51.09% DM and 33.67–34.14% DM, respectively, and DM content of 28.85–31.32%; in terms of fermentation quality, the pH value decreased from 4.85 in the sole C silage (C10Y0) to 4.04–4.11, the LA content increased from 13.91 g/kg DM to 28.86–30.87 g/kg DM, the LA/AA ratio rose from 1.31 to 3.37–3.97, and the NH₃-N content was reduced by 0.56–0.96% TN compared to the C10Y0 (decreasing to 4.16–4.45% TN), effectively inhibiting protein degradation; at the microbial level, the LAB count reached 9.03–9.05 log₁₀ CFU/g FM, an increase of 2.12–2.14 compared to the C10Y0, with a relative abundance exceeding 80%, successfully suppressing the proliferation of undesirable bacteria such as Raoultella and Weissella and ensuring fermentation stability. This provides technical support for utilizing this plant as a viable alternative forage resource. Full article

Background: Alzheimer’s disease (AD), a progressive brain disorder, is the most common form of dementia and necessitates the development of effective intervention strategies. Ginseng-Natto composite fermentation products (GN) have demonstrated beneficial bioactivities in mouse models of AD; however, the underlying mechanism of action through which GN ameliorates AD requires further elucidation. Methods: Mice received daily intragastric administration of low- or high-dose GN for 4 weeks, followed by intraperitoneal injection of scopolamine to induce the AD model. The pharmacological effects of GN were systematically evaluated using the Morris water maze test, ELISA, and H&E staining. To further investigate the underlying mechanisms, 16S rRNA gene sequencing and metabolomics were employed to analyze the regulatory effects of GN on the gut–brain axis. Additionally, Western blotting was performed to assess the impact of GN on blood–brain barrier (BBB) integrity. Results: GN intervention significantly ameliorated cognitive deficits and attenuated neuropathological injury in AD mice, restoring the brain levels of acetylcholine (ACh), acetylcholinesterase (AChE), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) to normal ranges. GN reshaped the gut microbiota by promoting beneficial bacteria and inhibiting pro-inflammatory strains. It also regulated key metabolic pathways related to amino acid and unsaturated fatty acid metabolism. This metabolic remodeling restored the compromised BBB integrity by upregulating tight junction proteins (ZO-1, Occludin and Claudin-1). Conclusions: Our findings demonstrate that GN ameliorates AD through a gut-to-brain pathway, mediated by reshaping the microbiota-metabolite axis and repairing the BBB. Thus, GN may represent a promising intervention candidate for AD. Full article

Cheese whey, the major by-product of the dairy industry, poses an environmental challenge due to its high organic load but simultaneously represents a nutrient-dense matrix suitable for biotechnological valorization. This review synthesizes recent advances positioning whey as (i) a fermentation substrate for lactic acid bacteria, yeasts/fungi, and microalgae, enabling the production of functional biomass, organic acids, bioethanol, exopolysaccharides, enzymes, and wastewater bioremediation; (ii) a platform for postbiotic generation, supporting cell-free preparations with functional activities; and (iii) a food-grade encapsulating material, particularly through whey proteins (β-lactoglobulin, α-lactalbumin), which can form emulsions, gels, and films that protect biotics and bioactive compounds during processing, storage, and gastrointestinal transit. We analyze key operational variables (whey type and pretreatment, supplementation strategies, batch and continuous cultivation modes), encapsulation routes (spray drying, freeze-drying, and hybrid protein–polysaccharide systems), and performance trade-offs relevant to industrial scale-up. Finally, we outline future directions, including precision fermentation, mixed-culture processes with in situ lactase activity, microfluidics-enabled encapsulation, and life-cycle assessment, to integrate product yields with environmental performance. Collectively, these strategies reframe whey from a high-impact waste into a circular bioeconomy resource for the food, nutraceutical, and environmental sectors. Full article

Microbial fermentation is an important means to enhance the nutrition and functionality of food, and soybean fermentation has a long history and a wide variety of products. This study systematically compared the effects of fermentation and post-ripening processes of Bacillus subtilis natto JLCC513 on the nutritional components, active substances, and sensory characteristics of soybeans. The experimental results showed that, in terms of basic nutrition, fermentation led to a significant decrease in fat and reducing sugar content, followed by an initial increase and then a decrease in total protein content. In contrast, water-soluble protein continued to increase, and the total amount of free amino acids surged. The active nutritional indicators before and after soybean fermentation showed that nattokinase activity continued to increase during fermentation and post-ripening. At the same time, the number of viable bacteria decreased slightly during post-ripening. The increase in the proportion of easily absorbed aglycone-type isoflavones before and after soybean fermentation is accompanied by a sustained increase in vitamin K2 and gamma aminobutyric acid (GABA) content. In terms of sensory quality, color-difference analysis shows a decrease in brightness (L value) and an increase in redness (a value), resulting in the characteristic yellow-brown color of natto. In terms of texture characteristics, the hardness decreases, while the viscosity and elasticity are significantly enhanced. Through GC-IMS analysis of volatile aromas during soybean fermentation and post-ripening, it was found that esters (such as ethyl acetate) and pyrazines (such as 2,3-dimethylpyrazine) increased, and the product flavor shifted from grassy to fruity and nutty. In summary, natto bacteria enhance the digestibility, nutritional value, and sensory acceptance of soybeans through enzymatic hydrolysis and metabolic transformation. The post-ripening stage plays a key role in flavor maturation and further accumulation of active ingredients. Full article

Kefiran, the extracellular polysaccharide produced by Generally Recognized as Safe (GRAS) bacteria found in kefir grains, is a promising biopolymer with multiple applications in agri-food and biomedical fields. Besides its characteristics and potential applications, the factors that affect its production remain a prime subject of interest. Lactic acid bacteria synthesize polysaccharides to protect their cells from adverse conditions. Therefore, low-temperature storage (4 °C) of kefir grains inoculated into Ultra-High-Temperature (UHT) milk at two different concentrations (5% and 30%) was studied as a factor for increasing kefiran production in the medium. The cryoprotectant disaccharide trehalose, which comprises a carbon and energy source for many microorganisms, was also evaluated for its effectiveness in enhancing kefiran production. The pH, the increase in kefir grain mass, the amount of kefiran produced, and the rheological properties of the acidified milk were determined during two distinct storage periods, depending on kefir grain concentration. For comparison, kefir grains were also fermented at 25 °C and 30 °C. Low-temperature storage at a kefir grain concentration of 30% resulted in an increase in the amount of polysaccharide produced beyond that obtained through fermentation. Fermentation of a 5% grain inoculum at 30 °C resulted in the lowest kefiran production. In the presence of trehalose, prolonged low-temperature storage favored an increase in the biosynthesis of kefiran, especially at a 30% kefir grain inoculum. Trehalose, however, was not a significant factor in the fermentation experiments. Proper selection of low-temperature storage time is required to avoid a reduction in kefiran concentration due to the metabolic activity of the microorganisms in kefir grains. The acidified milk (low-temperature storage) and kefir (fermentation) samples both exhibited increased elasticity and apparent viscosity with increasing kefir grain concentration. However, the rheological behavior of acidified milk was greatly affected by protein degradation during low-temperature storage. As shown by the findings of the present study, low-temperature storage (4 °C) of a 30% kefir grain inoculum in the presence of trehalose (3% w/w) until a final pH of 4.2 proves to favor kefiran production in the medium the most. Full article

Fermentation, one of the oldest food processing techniques, is known to play a pivotal role in improving the nutritional and functional characteristics of cereals, with positive implications for gut health and overall well-being. The present study aims to examine the phenolic acids, peptides, and potential bioactive properties of 2 novel sorghum-based fermented beverages, Niselo and Delishe. A total of 48 phenolic compounds were identified through targeted and untargeted Ultra-High Performance Liquid Chromatography coupled with a Quadrupole Orbitrap High-Resolution Mass Spectrometer (UHPLC–Q-Orbitrap HRMS) analyses, revealing a higher content of phenolic acids in Niselo and a prevalence of flavonoids in Delishe. Niselo exhibited enhanced in vitro cytoprotective and reactive oxygen species (ROS)-scavenging activity and displayed a clear cytoprotective effect against hydrogen peroxide-induced oxidative stress in Caco-2 cells. Proteomic profiling using tryptic digestion revealed that Niselo has a substantial abundance of fragments of peptides matching several stress-related and antioxidant proteins, indicating a superior stress-response and/or defense capability. Overall, these findings highlight the functional potential of sorghum-based fermented beverages, supporting their role as health-promoting products. Full article