Search Results (2,919)

This study addressed the challenges posed by wet-grade maize distiller’s dried grains with solubles (DDGS), which are characterized by high moisture and complex fibers that limit their storage and utilization in poultry feed. Three experiments were conducted to enhance their nutritional value through enzymatic and solid-state fermentation treatments. In vitro pre-digestion using multiple enzymes significantly improved dry matter solubility (DMS) and reducing sugar yield for maize DDGS and the ingredient maize germ meal (MGM). Using optimized parameters, wet-based DDGS-MGM was subjected to solid-state fermentation with 500 mg/kg of cellulase and 200 mg/kg of the X1 enzyme (a laboratory-developed multi-enzyme complex), and this treatment enhanced both DMS and reducing sugar yield, and the resulting fermented product was subsequently applied in further experiments. In the broiler trial, forty 22-day-old Arbor Acres broilers with similar body weights were randomly assigned to five treatment groups, including the control group, (50% DDGS + 50% MGM) unfermented group, (62.5% DDGS + 37.5% MGM) unfermented group, (50% DDGS + 50% MGM) fermented group, and (62.5% DDGS + 37.5% MGM) fermented group, with eight replicates per treatment (one broiler per replicate). Replacement of 30% of the basal diet with fermented 50:50 DDGS-MGM material significantly increased apparent metabolizable energy (AME) and nitrogen-corrected AME by 2.74 MJ/kg and 2.73 MJ/kg, respectively, corresponding to improvements of 39.60% and 40.81% compared to the unfermented control (p < 0.05). Economic analysis indicated that using 5% fermented DDGS-MGM in feed reduced cost by 20.45 RMB per metric ton. These findings demonstrate that bioprocessing can improve the utilization and economic value of maize processing by-products, although further validation under practical conditions is needed. Full article

This study characterised the diversity of filamentous fungi and yeasts during Malbec grape fermentation in the Southern Oasis of Mendoza (Argentina) winegrowing region, under different sanitary conditions and SO₂ treatments, using morphological and ITS-RFLP-based molecular methods. Alternaria, Cladosporium and Penicillium were present in both sound and damaged grapes, while Aspergillus and Botrytis were primarily found in damaged grapes. The predominant yeast species in both sound and damaged grape must, at lower and higher maturity levels, were Aureobasidium pullulans and Hanseniaspora spp. At higher grape ripening levels species diversity increased, with Hanseniaspora vineae, Metschnikowia pulcherrima and Candida membranifaciens dominating, and others such as Pichia kudriavzevii and Issatchenkia terricola appearing. A. pullulans and M. pulcherrima were highly tolerant to SO₂. Notably, the species Meyerozyma guilliermondii, Zygoascus hellenicus and Hanseniaspora uvarum were exclusively present in damaged grape must, while Zygosaccharomyces bailii was also found in sound grape must. Hanseniaspora spp. and P. kudriavzevii predominated at mid-fermentation and persisted at the end of the process, highlighting their resistance to wine conditions and their potential to influence post-fermentative dynamics. These findings emphasise the significant influence of grape sanitary status on mycobiota composition, with important implications for fermentation behaviour and final wine quality. Full article

Gossypol, a polyphenolic naphthalene derivative and yellow polyphenolic pigment found in cotton seed glands, presents notable environmental, animal, and human health hazards. To screen for yeast strains capable of utilizing gossypol and to investigate their removal efficiency and mechanisms. Yeast strains capable of utilizing gossypol as the exclusive carbon source were isolated from cotton field soil. The identification of these strains involved assessment of colony morphology, physiological and biochemical characteristics, and phylogenetic analysis utilizing 26S rDNA gene sequences. Safety evaluations included hemolytic and antibiotic susceptibility tests. The growth responses of the selected strains to varying temperatures and pH levels were determined. Using cotton meal as the solid fermentation substrate, the effects of single factors on gossypol removal by the strains were determined. The intracellular and extracellular localization as well as the nature of the gossypol-removing active components in the strains were characterized, followed by an investigation into the molecular mechanism of gossypol removal using LC-MS analysis. A total of 17 gossypol-utilizing strains were isolated from cotton field soil samples, with strain ZYS-3 demonstrating superior removal capability. Strain ZYS-3 was identified as Meyerozyma guilliermondii, exhibiting no hemolytic activity and susceptibility to nine commonly used antifungal agents. The optimal growth parameters for this strain were determined to be a temperature of 30 °C and a pH of 5.0. In solid-state fermentation using cotton meal at 30 °C with initial fermentation conditions (10% corn flour added as an external carbon source, 40% moisture content, and 6% inoculum concentration) for 3 days, strain ZYS-3 achieved a gossypol removal rate of 73.57%. Subsequent optimization of the fermentation process, including the addition of 10% corn flour as an external carbon source, adjustment of moisture content to 55%, and inoculum concentration to 10%, resulted in an increased gossypol removal rate of 89.77% after 3 days of fermentation, representing a 16.2% enhancement over the initial conditions. Assessment of gossypol removal activity revealed that strain ZYS-3 predominantly removes gossypol through the secretion of extracellular enzymes targeting specific active groups (phenolic hydroxyl groups and aldehyde groups) within the gossypol molecule. These enzymes facilitate oxidation and elimination reactions, leading to the opening of the naphthalene ring and subsequent removal of gossypol. Full article

Ensiling forage under low-temperature conditions often leads to poor fermentation and nutrient losses. This study evaluated the effects of a cold-tolerant Pediococcus pentosaceus OL77 strain on oat silage. Silages were prepared with or without Pediococcus pentosaceus inoculation (1 × 10⁵ cfu/g FM). After 90 days, OL77-treated silage showed markedly higher lactic acid (45.83 vs. 30.51 g/kg DM), lower pH (3.88 vs. 4.443), and better preservation of WSC (64.68 vs. 47.60 g/kg DM) and crude protein (89.26 vs. 65.52 g/kg DM) than the control. Microbial analysis revealed accelerated colonization by Pediococcus, reduced bacterial diversity, and faster stabilization of the fermentation process. Functional predictions indicated enhanced carbohydrate and energy metabolism. These findings demonstrate that OL77 can effectively improve fermentation quality and nutrient preservation of oat silage under low-temperature conditions, offering a practical inoculant option for cold regions. Full article

Sauce-flavor Daqu is the solid-state fermentation starter for sauce-flavor Baijiu. Its microbial community influences flavor formation, yet links between community change, process conditions, and flavor development during high-temperature fermentation remain unclear. We investigated Daqu fermentation by integrating high-throughput sequencing, monitoring of physicochemical parameters, and analysis of volatile compounds. Fermentation temperature showed three phases: rapid rise, fluctuating plateau, and gradual decline. High temperatures were associated with increased thermophilic microbes such as Bacillus and Thermoascus and with higher levels of reducing sugars and amino acid nitrogen; amylase, protease, and other hydrolase activities were detected. Bacterial composition varied more than fungal composition; Firmicutes and Ascomycota were the dominant phyla, and Bacillus and Thermoascus were abundant genera. Canonical correspondence analysis associated reducing sugars, acidity, and moisture with early community shifts, and amino acid nitrogen with later shifts; reducing sugars and moisture showed the strongest associations. Filamentous fungi and Bacillus correlated with pyrazine-type compounds. These results link microbial composition, process parameters, and flavor profiles, and may inform the standardization and mechanization of Daqu production. Full article

The parturition season of grazing Tibetan ewes spans from October to March, a period that exacerbates the adverse impacts of nutrient-deficient herbage on milk yield, body condition, and postpartum recovery. To alleviate the weight loss of ewes during the cold seasons, we provided concentrate supplements at four levels (dry matter (DM) basis), 260 g (C1), 440 g (C2), 520 g (C3), and 610 g (C4), alongside a basal diet of grazed pasture. A total of 96 multiparous Tibetan ewes (third parity, body weight: 45.17 ± 3.69 kg (body weight (BW) were enrolled within 12–18 h postpartum and randomly allocated to four dietary groups (n = 24 ewes per group). We measured growth performance, ruminal histomorphology, fermentation parameters, and digestive enzymes. A multi-omics technique (16S rRNA gene sequencing and RNA-seq) was employed to investigate the mechanisms underlying alterations in ruminal function. The results showed that increasing the concentrate level decreased body weight loss and increased average dry matter intake (p < 0.05). Rumen morphology was significantly altered: papilla width and muscle layer thickness were greatest in the C4 group, whereas submucosal thickness was highest in the C1 group (p < 0.05). Cellulase activity was lowest in the C1 group (p < 0.05). Papilla width of lactating Tibetan ewes in the C4 group was higher (p < 0.05) than that in the C1 and C3 groups. Concentrate supplementation altered ruminal microbiota composition and diversity. Each group exhibited a distinct microbial signature: the C1 group was characterized by Lachnospiraceae_XPB1014_group, Candidatus_Omnitrophus, Paenibacillus, and unclassified_Oligoflexaceae; the C2 group was enriched in Papillibacter, Anaerovibrio, V9D2013_group, and unclassified_Peptococcaceae; the C3 group was characterized by unclassified_Bacteroidales_RF16_group; and the C4 group was characterized by Ruminococcus, Pseudobutyrivibrio, and Mitsuokella (p < 0.05). Transcriptomic analysis identified differentially expressed genes (TRPA1, EPHB1, GATA3, C4, ABCG2, THBS4, and TNFRSF11B) that are predominantly involved in immune regulation, signal transduction, and nutrient digestion. The results of Spearman correlation analysis showed that Anaerovibrio was negatively correlated with propionate (r = −0.565, p < 0.05). However, it was positively correlated with the ratio of acetate and propionate (r = 0.579, p < 0.05). Moreover, Lachnospiraceae_XPB1014_group was negatively correlated with cellulase (r = −0.699, p < 0.05) and α-amylase (r = −0.514, p < 0.05). These findings suggest that the increasing concentrate supplementation alleviates body weight loss in lactating Tibetan sheep by orchestrating improvements in rumen histomorphology, digestive function, altering bacteria composition, and ruminal immune and modulating host epithelial gene expression. Full article

Ulva sp. is a fast-growing, widely distributed marine alga with significant potential across various sectors, yet it remains underutilised. This study optimised pressurised liquid extraction (PLE) to obtain high-value fractions from Ulva biomass. Using a Box–Behnken design and response surface methodology, the effects of sulfuric acid concentration, temperature, and extraction time on yield, reducing sugars, total carbohydrates, and phenolic content were evaluated. Optimal conditions were identified as 110 °C, three 15 min cycles, and 3.6% sulfuric acid. Under these parameters, the extract yielded 46.9 g/100 g dry weight (DW), with 244.0 mg of reducing sugars/g DW, and 15.4 mg GAE/g DW, aligning with model predictions. The hydrolysate supported fermentation by Lactiplantibacillus plantarum, resulting in a growth of ~9 log CFU and the production of 3.3 g/L of lactic acid within 48 h. The antioxidant capacity remained stable post-fermentation, with CUPRAC, DPPH, and ABTS values of ~52, 38, and 18 mg TE/g DW, respectively. This work demonstrates the effectiveness of PLE in extracting valuable compounds and the feasibility of microbial fermentation of the extracts. This integrated approach highlights the potential of Ulva biomass and offers a platform for further applications in food, cosmetics, and nutraceuticals. Full article

Dairy products harbor complex and dynamic microbial communities that contribute to their sensory properties, safety, and cultural distinctiveness. Raw milk contains a diverse microbiota shaped by seasonality, storage conditions, lactation stage, animal health, farm management, and genetics, serving as a variable starting point for further processing. Fermentation, whether spontaneous or starter driven, selects for subsets of lactic acid bacteria (LAB), yeasts, and molds, resulting in microbial succession that underpins both artisanal and industrial products such as kefir and cheese. Kefir represents a balanced LAB–yeast symbiosis, with species composition influenced by grain origin, milk type, and processing parameters, whereas the cheese microbiota reflects the interplay of starter and non-starter LAB, coagulants, ripening conditions, and “house microbiota”. Methodological factors—including DNA extraction, sequencing platform, and bioinformatic pipelines—further impact the reported microbial profiles, highlighting the need for standardization across studies. This review synthesizes current knowledge on raw milk, kefir, and cheese microbiomes, emphasizing the biological, technological, environmental, and methodological factors shaping microbial diversity. A holistic understanding of these drivers is essential to preserve product authenticity, ensure safety, and harness microbial resources for innovation in dairy biotechnology. Full article

Ensiling is the microbial processing of forage, based on the fermentation of plant sap that acidifies the silage to pH < 5. This acidity threshold prevents microbial activity that could otherwise produce inhibitory, toxic, malodorous or otherwise undesired metabolites. Anaerobic conditions are key to silage production and storage in silos because aerobic exposure would change the microbiota to counterproductive metabolism. This review outlines the principal microbial groups involved in the open ensiling process and discusses some additive effects with externally added compounds that have been used in this industry to enhance anaerobiosis, lactic acid fermentation, preservation, and safe storage. The ensiling process and the type of forage in the silage may impact methanogenesis in ruminants, and additional effects on ruminal digestion have also been reported. Full article

Due to its high content of lignocellulose, cotton stalk is difficult to degrade naturally and utilize effectively, so it is often regarded as waste. In this study, the effects of Pleurotus ostreatus XH005, Lactiplantibacillus plantarum LP-2, and cellulase enzyme on the cotton stalk substrate under aerobic solid-state fermentation (SSF) conditions were investigated, and the metabolites were analyzed to identify potential functional compounds in the cotton-stalk-fermented feed. Preliminary optimization results obtained through single-factor experiments were as follows: fermentation time 14 days, XH005 inoculum size 8.00% (v/m), material-to-water ratio 1:0.50 (v/m), LP-2 inoculum size 2.00% (v/m), and cellulase addition 0.60% (m/m). Based on these single-factor experimental results, XH005 inoculum size, LP-2 inoculum size, material-to-water ratio, and cellulase addition were selected as independent variables. Through response surface methodology (RSM) optimization experiments, 29 experimental groups were designed. Subsequently, based on Box–Behnken analysis of variance (ANOVA) of lignin and cellulose content, along with contour and response surface plots, the optimal aerobic solid-state fermentation parameters were determined as follows: fermentation time 14 days, XH005 inoculum: 7.00% (v/m), material-to-water ratio: 1:0.55 (v/m), LP-2 inoculum: 2.00% (v/m), and cellulase enzyme addition: 0.65% (m/m). Results showed that compared with the control group (CK), the optimized group exhibited a 27.65% increase in lignin degradation rate and a 47.14% increase in cellulose degradation rate. Crude protein (CP) content increased significantly, while crude fiber (CF), detergent fiber and mycotoxin contents decreased significantly. Non-targeted metabolic analysis indicated that adding cellulase and inoculating Pleurotus ostreatus XH005 and Lactiplantibacillus plantarum LP-2 in aerobic SSF of cotton straw feed produced functionally active substances such as kaempferol (C343), carvone (C709) and trilobatin (C604). Therefore, this study demonstrates that microbial-enzyme co-action SSF significantly enhances the nutritional composition of cotton stalk hydrolysate. Furthermore, this hydrolysate is suitable for the production of functional compounds, endowing the fermented feed with health-promoting properties and enhancing the utilization of cotton processing byproducts in the feed industry. Full article

Anaerobic digestion (AD) is a mature industrial fermentation technology for converting organic matter into renewable bioenergy, and chicken manure (CM) is a promising feedstock due to its high organic content. However, the industrial-scale AD of CM is often hindered by ammonium inhibition, particularly under high organic loading rates (OLRs). Biochar has emerged as a sustainable additive that can enhance microbial activity, buffer pH, and improve system stability. In this study, the effects of biochar on the methane production and fermentation performance of CM in terms of AD were evaluated under both batch and continuous conditions, where batch experiments were conducted at different biochar-to-CM ratios. Ammonium nitrogen and methane production were monitored to determine the optimal biochar addition ratio. Continuous stirred-tank reactors (CSTRs) were then operated with the optimal biochar addition ratio under stepwise-increasing OLR conditions to assess methane production, fermentation parameters, and methanogen community composition. The results showed that an optimal biochar addition of 9% reduced total ammonium nitrogen (TAN) by 31.75% and increased cumulative methane production by 25.93% compared with the control. In continuous operation, biochar addition mitigated ammonium inhibition, stabilized pH, enhanced system stability and organic loading capacity, and improved methane production by 21.15%, 27.78%, and 83.33% at OLRs of 2.37, 4.74, and 7.11 g volatile solids (VS)/(L·d), respectively, compared to the control. Biochar also inhibited the growth of methylotrophic methanogen of RumEn_M2. These findings provide scientific and technical support for applying biochar as a process enhancer during the AD of CM. Full article

This study focuses on determining the optimal fig and butyric acid concentrations for butanol production under thermophilic conditions. Waste fig is a potentially rich substrate in sugars, minerals, and vitamins, but it is insufficient for effective butanol formation when butyrate is not present in the media because butanol is produced by butyrate reduction. Therefore, butyric acid was supplemented gradually in certain concentrations to fig-containing fermentation broth. The best combination of butyric acid and fig was determined using the Box–Wilson statistical experiment design. Fig and butyric acid concentrations were set as independent variables, while butanol concentration was the objective function. When the concentrations of butyric acid and fig were near the middle of the ranges under inspection, more butanol was produced. Butanol production was the lowest as fig and butyric acid values got closer to the extremes, particularly at high concentrations. Maximum butanol of 0.32 g/L was obtained with 16 g fig/L and 1.6 g butyric acid/L. The quadratic model generated was found to be significant, and its reliability was tested with verification experiments with reproducible results. This study showed that butanol could be produced from butyrate-supplemented fig waste under thermophilic conditions with a consolidated bioprocessing approach. Full article

Ethyl carbamate, a genotoxic chemical contaminant present in fermented alcoholic beverages and foods, is formed from naturally occurring substances in these beverages and foods. Studies have shown that the content of ethyl carbamate can increase significantly during product storage and maturation, especially if favorable conditions are present. Higher levels of ethyl carbamate have been associated with distilled alcoholic beverages, mainly obtained from stone fruits. Ethyl carbamate content is lower in fermented foods, such as bread, yogurt, and fermented sauces. EC formation occurs through several different pathways in food systems. A primary pathway involves select compounds reacting with ethanol (EtOH); therefore, the majority of the research has focused on the occurrence of EC in alcoholic beverages Due to health risks, some countries have imposed legal limits on carbamate content in alcoholic beverages. Full article

The development of non-alcoholic beer (NAB) with health benefits, using non-conventional potential probiotic yeasts, offers an interesting alternative to standard NAB brewing strategies. In this study, potential probiotic non-Saccharomyces yeasts Pichia manshurica, Kluyveromyces lactis, and Kluyveromyces marxianus, along with commercial probiotic yeast Saccharomyces boulardii, were characterised and tested for functional NAB production, whereas P. manshurica was used in NAB production for the first time. Growth and viability were assessed across a range of temperatures, pH, and iso-α-bitter acids. The tested yeasts withstood conditions typical of the beer matrix and human digestive tract and had a positive phenolic off-flavour phenotype. Two strains, K. lactis and K. marxianus, showed strong β-glucosidase activity, which may enhance beverage aroma complexity. Ethanol levels in beers fermented with non-Saccharomyces yeasts remained below the NAB limit (≤0.5% v/v). An analysis of volatile organic compound profiles revealed the potential of these yeasts to produce higher alcohols and esters valuable from a brewer’s perspective. This study provides valuable insight into novel probiotic fermentations and the potential application of unconventional yeasts in functional, aromatic, and health-oriented non-alcoholic beverages. Full article

This study addresses volatile fatty acid (VFA) accumulation, a key issue limiting methane fermentation under high organic loading rate (OLR) conditions. Batch experiments were conducted with GAC (0–10%) under various OLRs (1:0.5–1:10) to investigate its effect on biogas yield, methane purity, and microbial interactions. Higher GAC levels (7.5% and 10%) significantly enhanced biogas production (750–800 mL/g VS) and methane concentration (–70%) while shortening stabilization time. A continuous system with 10% GAC showed suppressed VFA accumulation, stable pH (7.0–8.1), and improved organic matter degradation. This work quantitatively evaluates the link between GAC dosage, DIET induction, and microbial community shifts under high OLR. These findings highlight GAC as an operationally simple and potentially cost-beneficial strategy for stabilizing methane fermentation, particularly in decentralized or small-scale applications. Full article