Search Results (448)

The synchronization between nitrogen sources and carbohydrate fractions represents a critical factor for optimizing microbial protein synthesis and overall ruminant performance. This systematic review, conducted according to PRISMA 2020 guidelines, comprehensively evaluated the interactions between different nitrogen sources (true protein, urea, controlled-release urea, and bypass amino acids) and carbohydrate fractions (rapidly degrading soluble, slowly degrading soluble, fibrous, non-fibrous, and Van Soest fractions) in ruminant nutrition. A comprehensive search across PubMed, ScienceDirect, Web of Science, and Scopus databases identified 1855 records, of which 164 studies met the eligibility criteria for qualitative synthesis and 89 for quantitative meta-analysis. The review reveals that synchronization effectiveness varies significantly depending on the nitrogen source–carbohydrate combination, with controlled-release urea showing superior synchrony with slowly degrading carbohydrates, while conventional urea performs better with rapidly degrading sources. Meta-analytical results indicate that optimal nitrogen–carbohydrate synchronization can improve microbial protein synthesis by 18–34%, reduce urinary nitrogen excretion by 12–28%, and enhance feed efficiency by 8–15%. These findings provide evidence-based recommendations for precision nutrition strategies in ruminant production systems. 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

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

Microbial lipid production from renewable carbon sources, particularly lignocellulosic hydrolysates, is a promising alternative to plant-derived oils and fats for food applications, as it can minimize the land use by utilizing agricultural wastes and byproducts from food production. In this context, a standard approach to prevent oxygen limitation at reduced air gassing rates during long-term aerobic microbial processes is to operate bioreactors at increased pressure for elevating the gas solubility in the fermentation broth. This study investigates the effect of absolute pressures of up to 2.5 bar on the conversion of the carbon sources (glucose, xylose, and acetate), growth, and lipid biosynthesis by Cutaneotrichosporon oleaginosus converting a synthetic nutrient-rich lignocellulosic hydrolysate at low air gassing rates of 0.1 vessel volume per minute (vvm). Increasing pressure delayed xylose uptake, reduced acetic acid consumption, and reduced biomass formation. Lipid accumulation decreased with increasing pressure, except for fermentations at 1.5 bar, which achieved a maximum lipid content of 83.6% (±1.6, w/w) (weight per weight in %). At an absolute pressure of 1.5 bar, a lipid yield from glucose, xylose, and acetic acid of 38% (w/w) was reached after 6 days of fermentation. The pressure sensitivity of C. oleaginosus may pose challenges on an industrial scale due to the dynamic changes in pressure when the yeast cells pass through the bioreactor. Increasing liquid heights in full-scale bioreactors will result in increased hydrostatic pressures at the bottom, substantially reducing lipid yields, e.g., to only 23% (w/w) at 2.0–2.5 bar, as shown in this study. However, further scale-up studies with dynamic pressure regimes (1–2.5 bar) may help to evaluate scale-up feasibility. Full article

Pile fermentation is a crucial process for developing the characteristic mellow taste and aged aroma of dark tea, yet the internal quality transformation mechanism of this process is still unclear. This study employed a high-sensitivity analytical platform based on gas chromatography–mass spectrometry (GC-MS) to systematically investigate the dynamic interplay between key chemical components, enzyme activities, and volatile compounds during the pile fermentation of primary dark tea. Our findings revealed a significant decrease in ester-type catechins, crude protein, and protopectin, alongside a notable accumulation of non-ester-type catechins, gallic acid, and soluble components. The multi-enzyme system—comprising PPO/POD, pectinase/cellulase, and protease—cooperatively drove the oxidation of phenols, cell wall degradation, and the release of aromatic precursors. This was complemented by GC-MS analysis, which identified and quantified 103 volatile compounds across nine chemical classes. The total content of volatile compounds increased significantly, with alcohols, esters, and aldehydes/ketones being the dominant groups. Floral and fruity compounds such as linalool and geraniol accumulated continuously, while esters exhibited an initial increase followed by a decrease. Notably, carotenoid degradation products, including β-ionone, were significantly enriched during the later stages. This study revealed a “oxidation–hydrolysis–reconstruction” metabolic mechanism co-driven by microbial activity and a multi-enzyme system, providing a theoretical foundation for the precise regulation of pile fermentation and targeted quality improvement of primary dark tea. Full article

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants posing ecological risks in wastewater. Constructed wetlands (CWs) offer sustainable treatment through integrated biological processes. In this study, a biomimetic microbial CW reactor was developed using 30 L aquariums with porous media, aeration setups, and surface plants to simulate natural wetland conditions. This design combines enhanced microbial degradation strategies using fungal (Trametes versicolor), bacterial (Pseudomonas aeruginosa), and consortia degradation, integrating multiple biological pathways. Synthetic wastewater containing 100 mg/L of selected PPCPs, including caffeine, methylparaben, and trichlorocarbanilide (TCC), was used to evaluate the degradation potential of these microbial treatments. While caffeine and methylparaben were effectively targeted, TCC degradation was inconclusive due to solubility limitations in the selected solvent. Over three months, system stability, plant growth, and microbial biomass were monitored, and contaminant degradation was tracked using Nuclear Magnetic Resonance analysis. Results demonstrated that individual fungal and bacterial treatments achieved near-complete caffeine degradation (99–100%) within seven weeks, while the combined treatment accelerated this process to just four weeks. Methylparaben followed a similar trend, achieving complete degradation by the seventh week. This study highlights the potential of microbial CW systems fortified with targeted microbial consortia as a scalable solution for pollutant removal. Future work should refine microbial combinations and analytical methods to expand the range of treatable pollutants. Full article

Vegetable cultivation is currently facing complex challenges related to climate change, with negative repercussions on plant performance. In this scenario, the employment of eco-friendly agronomic tools capable of boosting plant tolerance to abiotic stresses is fundamental. Among them, the use of non-microbial biostimulants, such as seaweed extracts (SwEs), and microelements, like selenium (Se), is considered an efficient approach to overcome abiotic stresses. In this experiment, the performance of chicory plants cultivated under three different irrigation levels (100%, 75% or 50% of substrate water holding capacity) and treated with SwE, Se or their combination (SwE + Se) was evaluated. The results revealed that drought stress significantly decreased growth, productivity and relative water content but increased soluble solid content, dry matter percentage, and proline and malondialdehyde concentrations. The application of Swe, Se or Swe + Se enhanced growth, productive features and soluble solid content and reduced dry matter percentage, proline and malondialdehyde compared to the control. Based on our results, Se and SwE combined application could be a valuable approach to face moderate drought stress on curly endive plants and improve productive and quality traits. Full article

Reverse osmosis (RO) is the key process for textile dyeing wastewater reuse applications. Membrane fouling reduces both permeability and rejection capability, negatively affecting the technological economy of RO process. Membrane cleaning is critical to recovery of the permeability of fouled RO membranes. Based on multi-batch filtration and cleaning experiments, this study systematically evaluated the RO membrane fouling potential of pre-treated textile dyeing wastewater by a membrane bioreactor and the recovery performance of fouled RO membranes after different cleaning methods. A significant decline (more than 15%) in RO membrane permeability occurred after RO membrane permeate production of 625 L/m² at a water recovery ratio of 60%. Protein-like substances and soluble microbial products were identified as the primary organic foulants via three-dimensional fluorescence excitation-emission matrix spectrometry (3D-FEEM). The single forward flushing with either pure water, acid, alkaline, or sodium hypochlorite solutions with a low active chlorine concentration showed very limited recovery of fouled RO membrane permeability. The combined forward flushing with acid followed by alkaline solutions restored fouled membrane permeability by up to 87% of a new RO membrane. The addition of pure water backwashing at a transmembrane pressure (TMP) of 0.5 MPa after both acid and alkaline solutions combined forward flushing restored fouled membrane permeability by up to 97% of a new RO membrane but deteriorated the rejection capability of the RO membrane. The backwashing parameters were further optimized at a TMP of 0.125 MPa and crossflow velocity (CFV) of 0.5 m/s, achieving fouled RO membrane permeability by up to 96% of a new RO membrane, and there were no negative effects on the rejection capability of the RO membrane. Alkaline forward flushing followed by pure water backwashing was the dominant contributor for fouled RO membrane permeability recovery. A preliminary economic analysis showed that the total chemical cost per RO production was 0.763 CNY/m³ and could be further reduced via removing acid cleaning and replacing combined alkaline flushing and pure water backwashing with alkaline backwashing. Full article

Oat is a forage with high protein value (10–14% DM) and good palatability, and is considered one of the main feed sources for ruminants. In this experiment, Lacticaseibacillus rhamnosus and Lentilactobacillus buchneri were selected as silage additives to investigate the fermentation quality, nutrient composition, microbial community and relationship between fermentation products and bacterial community of small-bale oat silage after ensiling. The experiment was set up with three treatment groups and three replications in each group, which were the control (C) group, L. rhamnosus (LR) group and L. buchneri (LB) group, and oat silages were subjected to 10-day and 30-day storage periods. The results show that both LR and LB additions significantly increased water-soluble carbohydrate, crude protein, lactic acid, propionic acid and acetic acid contents, and decreased pH, butyric acid, acid detergent fiber, neutral detergent fiber, and ammonia nitrogen contents and yeast and enterobacteria numbers in small-bale oat silage, compared with the C group. The highest content of acetic acid and the lowest numbers of enterobacteria and yeast were found in the LB group after 30 days of fermentation. Lentilactobacillus and Lacticaseibacillus were the dominant genera in the LB and LR groups, regardless of fermentation time. Lentilactobacillus and Lacticaseibacillus were positively correlated with a correlation value of 0.9, but both were negatively correlated with Bacillus. Lentilactobacillus and Lacticaseibacillus were positively correlated with acetic and lactic acids, while pH and butyric acid were positively correlated with Bacillus. This experiment revealed that the addition of homofermentative and heterofermentative lactic acid bacteria enhanced the relative abundance of Lentilactobacillus and Lacticaseibacillus, reduced harmful microbes, and improved fermentation quality of small-bale oat silage. Full article

Potassium (K) is a vital macronutrient for plant growth and yield, yet most soil K occurs in insoluble mineral forms, limiting availability to crops. Reliance on chemical K fertilizers is unsustainable due to cost and environmental concerns. Microbial solubilization of mineral K, particularly by purple nonsulfur bacteria (PNSB), offers an eco-friendly alternative. This study focused on isolating mica-potassium-solubilizing purple nonsulfur bacteria (MK-PNSB) from in-dyke alluvial soil and assessing their effects on hybrid maize germination and seedling growth. Among the isolates, the results showed that strain M-Wa-19 released the highest amount of soluble K under microaerobic light conditions (27.4 mg∙L⁻¹). Under aerobic dark conditions, M-Wa-24 and M-Wa-26 released 20.1–21.0 mg∙L⁻¹ of soluble K. Strains M-Wa-21, M-Wa-25, and M-Sl-13 solubilized K in the range of 14.3–25.1 mg∙L⁻¹ and 12.9–24.4 mg∙L⁻¹ under both incubation conditions. The selected strains were identified by 16S rRNA as Rhodopseudomonas palustris strain M-Sl-13 (PX588604), Rhodoplanes pokkaliisoli strain M-Wa-19 (PX588605), Afifella marina strain M-Wa-21 (PX588606), Rhodocista pekingensis strain M-Wa-24 (PX588607), Rhodocista pekingensis strain M-Wa-25 (PX588608), and Rhodocista pekingensis strain M-Wa-26 (PX588609). None exhibited toxicity to maize seeds; instead, all enhanced seed vigor indices by up to 99.7% and improved plant height and root biomass by 19.0–26.2% and 14.4–22.9%, respectively, under static hydroponic conditions. At a 1:1000 (bacteria and distilled water) dilution rate, strains M-Wa-26, M-Wa-25, M-Sl-13, M-Wa-24, M-Wa-19, and M-Wa-21, along with the six-strain mixture, improved seed vigor index by 3.96–7.91%. These findings suggest that MK-PNSB, individually or in mixtures, hold promise as biofertilizer candidates for sustainable K management in crop production. Full article

Fu brick tea (FBT) develops its characteristic qualities through fermentation, yet how variation in the chemical composition of raw dark tea (RDT) is associated with microbial succession and final tea quality remains unclear. In this study, three grades of RDT (premium-grade (1M), first-grade (2M), and second-grade (3M)) were processed into FBT under identical conditions to examine the relationship between initial composition, microbial community structure, and sensory attributes. Results revealed that high-grade RDTs (1M) contained higher levels of water extracts (WE, 36.35 ± 0.14 (%), p < 0.05), total polyphenols (TP, 14.93 ± 0.19 (%), p < 0.05), and free amino acids (FAA, 2.90 ± 0.03 (%), p < 0.05), promoting Aspergillus (96.06% in C1M, compared with 66.43% in C2M and 55.01% in C3M) dominance and resulting in brighter liquor with enhanced body and smoothness. Correlation analyses demonstrated a coherent sequence from substrate composition to microbial assembly and then to quality-related chemistry. WE, TP, and FAA were positively correlated with Aspergillus abundance and body and smoothness (p < 0.05), whereas soluble sugars correlated with Rhodotorula and sweetness (p < 0.05). These findings support a substrate-mediated association framework in which the chemical composition of RDT is closely aligned with microbial community structure and sensory differentiation during FBT fermentation, providing a scientific basis for raw material grading and fermentation management in dark tea production. Full article

Biostimulants boost plant growth, productivity, and nutrient retention, and can be produced from agri-food waste via microbial fermentation. In this study, undersized and unsold kiwifruits were fermented with Lactiplantibacillus plantarum to produce a fermented kiwifruit-based biostimulant (FKB). FKB was applied to soilless tomato plants (cv. Solarino) at two concentrations (50 and 100 mL L⁻¹) at the root level, every two weeks throughout the crop cycle. Fruits were analyzed for technological and chemical parameters, including color, texture, total soluble solids, titratable acidity, sugar/acid ratio, pH, electrical conductivity, total polyphenol content, antioxidant activity, and lycopene concentration. Additionally, metataxonomic analysis characterized the substrate microbial community at the beginning and the end of cultivation. Overall, the results indicate a dose-dependent effect of FKB on fruit quality parameters, with the highest concentration showing the most pronounced effects, specifically for the fruit firmness (8.02 N for FKB at 100 mL L⁻¹ vs. 7.25 N for the Control). Moreover, both tested concentrations were associated with increased antioxidant activity (on average +28%), and lycopene content (on average +57%) compared with the Control fruits. While overall microbial diversity remained largely unchanged, the relative abundance of bacterial taxa associated with nutrient cycling and plant–microbe interactions was modulated by the biostimulant, indicating subtle but potentially functionally relevant shifts in the rhizosphere microbiota. These findings suggest that fermented kiwifruit biomass can serve as an effective biostimulant, improving both fruit quality and the functional structure of the rhizosphere microbial community in soilless tomato cultivation. Full article

There are large amounts of carbohydrates and proteins in rban perishable organic waste (UPOW), which can be converted to short chain fatty acids (SCFAs) through microbial methods. In this study, the mass balance and properties of organic slurry generated from UPOW pretreatment were investigated first. Then, the optimal conditions for SCFAs production from organic slurry of UPOW was studied. It was found that under the conditions of pH 8 ± 0.5 and reaction time of 3 d, the yield of SCFAs, mainly composed of acetic and propionic acids, in the full-scale reactor was 0.68 gCOD/gTCOD of organic slurry. Under the conditions of influent NH₄⁺-N, total nitrogen, soluble ortho-phosphorus, and soluble COD of 27–39, 33–45, 2–9, and 220–300 mg/L, respectively, the use of SCFAs-enriched fermentation liquid (100 mg COD/L) as the additional carbon source for full-scale biological municipal wastewater treatment showed a higher total nitrogen and phosphorus removal efficiency than that of sodium acetate (88.1 ± 5.2% against 81.4 ± 4.5% and 96.9 ± 3.1% versus 91.5 ± 2.8%) due to greater key enzyme activity and short-cut nitrification and denitrification capacity. Finally, based on the actual operation process, an economic benefit analysis on the production of SCFAs-enriched fermentation liquid from UPOW was conducted, and the issues that need to be addressed for the promotion and application of this technology were discussed. This study contributes to achieving sustainable synergistic treatment of organic waste and wastewater. Full article

Chinese Baijiu distiller’s grains are by-products of the Chinese Baijiu brewing process, characterized by high water content, high acidity, and high fiber content, which make them unsuitable for animal feed, especially for monogastric animals. This study investigated the possibility of increasing the feed value of Nong-flavor Baijiu distiller’s grains (NFBDGs) for monogastric animals via solid-state fermentation by microbial-enzyme synergy. Experiments evaluated microbial growth, pH variation, improvement of crude protein (CP), true protein (TP), and acid-soluble protein (ASP), degradation of crude fiber (CF), acid detergent fiber (ADF), and neutral detergent fiber (NDF). The results indicated that Ligilactobacillus salivarius CRS23, Bacillus subtilis YLZ7, Saccharomyces cerevisiae CJM26, and xylanase were identified for the fermentation of NFBDGs. When the initial moisture content of NFBDGs was 60% and the initial pH was 3.4, under the conditions of aerobic fermentation at 37 °C for 4 days, the pH of NFBDGs increased from 3.49 to 6.04, the contents of CP and TP increased by 33.59% and 31.21%,,, respectively, while the contents of CF, ADF, and NDF decrease by 35.44%, 20.53%, and 25.02% respectively. The nutritional value of NFBDGs was significantly improved after microbial-enzyme synergistic fermentation, providing a new approach for their application as feed. Full article

Bioprocessing grape pomace (GP) presents a sustainable solution aligned with circular economic principles and transforms it into valuable functional ingredients for baked products. This review (2020–2025) synthesizes enzymatic and microbial strategies that modify the fiber–phenolic matrix and improve dough performance. Enzyme-assisted extraction, alone or combined with ultrasound or pressurized liquids, increases extractable polyphenols and antioxidant capacity in GP fractions used as flour substitutions or pre-ferments. Fungal solid-state and lactic fermentations liberate bound phenolic compounds and generate acids and exopolysaccharides. Among these routes, enzyme-assisted extraction and lactic sourdough-type fermentations currently appear the most compatible with bakery-scale implementation, offering substantial phenolic enrichment while relying on relatively simple, food-grade equipment. In current bakery applications, GP is mainly used as crude grape pomace powder, which typically shows higher total phenolics and antioxidant capacity. Moreover, in several models it lowers starch hydrolysis and predicted glycemic index. The practical substitution rate is between 5 and 10% of flour, which balances nutritional gains with processing disadvantages. These can be mitigated by fractionation toward soluble dietary fiber or co-fortification with flours rich in protein and fiber. An additional benefit of these methods includes reduced mycotoxin bioaccessibility in vitro. A key evidence gap is the absence of standardized comparisons between raw and bioprocessed GP in identical formulations. Overall, GP emerges as a promising ingredient for bakery products, while the added technological and nutritional value of bioprocessing remains to be quantified. Full article