Search Results (1,626)

Macrofungi are renowned for their rich nutritional and bioactive compounds. This study aimed to assess bioactive compounds, amino acids, and functional properties of flours produced through solid-state fermentation of bean and rice co-products with macrofungi. Three species (Pycnoporus sanguineus, Fistulina hepatica, and Laetiporus cincinnatus) were cultivated in humidified and sterilized broken ‘carioca’ beans or in a mixture of broken beans (70%), rice bran (20%) and broken rice (10%). Following fermentation, the colonized biomass was dried and milled into flour. The sample derived from broken beans cultivated with F. hepatica (102F) exhibited significantly higher β-glucans content (50.75 mg/g) of flour. All fermented flour samples showed elevated essential amino acid levels surpassing those reported in the literature for carioca beans. Phenolic compounds exhibited a notable increase, exceeding threefold in total phenolic content in the fermented samples. Sample 102F particularly excelled in antioxidant and cytotoxic activities. Principal component analysis revealed that these properties were linked to the highest content of β-glucans and specific phenolic compounds, such as sinapic and ellagic acids. These findings indicate that solid-state fermentation effectively enhances the nutritional and bioactive profile of bean and rice co-products, with F. hepatica emerging as the most promising treatment for bean and the bean–rice mixture. Full article

The quality and flavor of probiotic fermented milk are highly dependent on the strain composition of the starter culture and their metabolic interactions. Although constructing a multi-strain system is an effective strategy for enhancing product quality, traditional formulation methods rely heavily on empirical approaches and lack mechanistic guidance. Herein, this study utilized genome-scale metabolic models (GEMs) to rationally design a multi-strain co-fermentation system. The results demonstrated that the GEM-predicted optimal system, comprising Lacticaseibacillus paracasei subsp. paracasei 63 (L. paracasei subsp. paracasei 63) and Lactococcus cremoris 290 (Lc. cremoris 290), significantly reduced the curd time by approximately 44.0% and 71.0% compared to the L. paracasei subsp. paracasei 63 and Lc. cremoris 290 monocultures, respectively. Furthermore, the co-fermented milk exhibited a 4.3-fold increase in apparent viscosity relative to the 290 single-strain group and achieved a significantly higher diacetyl concentration (1.98 ± 0.09 mg/L), representing a 2.8-fold enhancement. Volatile flavor profiling and untargeted metabolomics provided suggestive evidence supporting the GEM-predicted cross-feeding mechanisms, particularly within the arginine and pyruvate metabolic pathways. This study offers a solid theoretical foundation and practical guidance for the rational design of synthetic microbial communities to develop high-quality fermented dairy products with optimized flavor and functional properties. Full article

Waste from the fruit juice industry presents high sugar and phenolic contents, high humidity and biological activities and cumbersome disposal or low-added valorization. Orange-peel waste (OPW) represents 35–55% w/w of processed fruit, with oranges being the main citric crop. OPW saccharification leads to sugar-rich hydrolysates that can be further processed via fermentative and catalytic routes. In this work, OPW enzymatic hydrolysis was studied via batch and fed-batch processing using either a 50 mM citrate buffer or a 9 g/L NaCl solution with pH control by adding CaCO₃ to ensure high enzyme activity across the enzymatic process. Preliminary runs showed that particle size of 3.4 mm diameter and a 300 r.p.m. stirring speed, a six-blade Rushton turbine and wall baffles were adequate to reach high sugar yields in batch. Further scale-up in batch at medium solid loading (12.5% w/w) and fed-batch operation at high-solid loading (20% w/w) led to high yields and glucose and fermentable sugars (up to 74 and 136 g/L, respectively, when using the saline solution and CaCO₃ as pH-controlling agent, in only 50 h; notably shorter and higher than when using the citrate buffer). Fractal kinetic models have been shown to accurately represent the compositional change across all batch and fed-batch conditions, highlighting NaCl reaction medium and alkali-driven pH control as the most appropriate approach to achieve high yields at low process times, a promising result for further developments at demonstration and industrial scales using automatic pH control. Full article

Caproic acid (CA) production through ethanol-driven chain elongation (CE) is a promising pathway to valorize organic wastes. However, the effect of pH and inoculum source on substrate conversion properties and microbial communities was not fully explored. In this study, performance of caproic acid production with anaerobic methanogenic sludge (AMS), aerobic sludge (AS) and chain elongation sludge (CES) at different pH conditions (uncontrolled (UN), 5, 6, and 7) were investigated. It was found that microorganisms in all inocula could degrade ethanol, but the consumption rate was different. The AS mainly used substrate for biogas production, without CA accumulation, while AMS and CES could synthesize butyrate and caproate with ethanol and acetate as substrates. At pH UN and 5, excessive ethanol oxidation (EEO) was activated and transformed ethanol into acetate resulting in low CA yield. Increasing pH to 7, the AMS produced more caproate and achieved a higher CA yield (0.36 g-COD/g-COD) than that of CES (0.33 g-COD/g-COD). Microbial communities in raw inocula were different, which led to distinct substrate conversion pathways. After fermentation, Anaerolineaceae was the dominate family in AMS, while Corynebacteriaceae and Dysgonomonadaceae dominated in the reactor with CES, explaining the distinct caproate yield in both reactors. The results of this study provided useful information for constructing ethanol-driven CE processes from organic wastes. Full article

To sustain egg production and gut health in aging flocks, the poultry industry seeks alternative synbiotic feed supplements. This study aimed to optimize Pediococcus acidilactici V202-fermented rice bran (PFR) and evaluate its effects on nutrient digestibility and cecal microbial populations in aged laying hens. In experiment 1, solid-state fermentation conditions (substrate particle size, moisture, and temperature) were optimized for viable lactic acid bacteria (LAB) counts. In experiment 2, in vitro assays were used to assess cecal fermentation kinetics. Subsequently, an in vivo trial involving twenty 80-week-old Hy-Line Brown hens evaluated the impact of PFR supplementation on nutrient digestibility and microbial profiles compared to a control diet. For experiment 1, the optimized fermentation conditions consisted of 40-mesh rice bran, a 30:70 bran-to-water ratio, incubation at 39 °C for 12 h, and drying at 40 °C, which produced the highest viable LAB counts. For experiment 2, PFR enhanced in vitro cumulative cecal gas production. In vivo, compared to the control, PFR supplementation significantly increased the apparent digestibility of dry matter (82.69% vs. 77.03%; p = 0.014), crude protein (82.75% vs. 75.38%; p = 0.016), crude fiber (36.30% vs. 23.10%; p = 0.015), ether extract (86.70% vs. 82.91%; p = 0.016), and gross energy (78.31% vs. 74.99%; p = 0.026). Furthermore, PFR beneficially modulated cecal microbial populations, increasing LAB while reducing Salmonella spp. In conclusion, these findings suggest that optimized PFR could be a promising synbiotic supplement to improve digestive efficiency and support beneficial cecal microbial populations in aged laying hens. Full article

This study characterized the physicochemical, rheological, and sensory parameters of five commercial natural-flavored yogurt brands available in the Peruvian highland’s region. The methodology included proximate composition, pH, titratable acidity, soluble solids, color (CIELab*), flow properties, viscoelastic behavior, and consumer sensory analysis using CATA questions and an acceptability test. The results revealed high variability among samples: soluble solids ranged from 7.24 to 16.27 °Brix, acidity from 0.68 to 1.03%, and two distinct rheological groups were identified: firm yogurts (G′ > 190 Pa) and soft yogurts (G′ < 30 Pa). Sensory attributes such as “pleasant texture,” “creamy,” and “milky flavor” positively influenced acceptability, whereas “acidic” and “watery” attributes negatively affected it. The sample with a balanced sensory profile (moderately sweet and creamy) achieved the highest acceptability score (7.8/9). It is concluded that yogurt quality in the highlands market is heterogeneous and that consumer acceptability depends more on sensory balance than on firmness alone. It is recommended that the dairy industry standardize fermentation processes to control acidity and optimize texture, prioritizing creaminess and homogeneity, and that regulatory authorities strengthen monitoring of these critical parameters to ensure safe and consistent products. Full article

The increasing demand for safer and environmentally sustainable products has intensified the search for natural alternatives to synthetic dyes. Filamentous fungi are promising sources of natural pigments due to their metabolic diversity and the feasibility of large-scale production. In this study, filamentous fungi isolated from Amazonian freshwater environments were evaluated for their potential to produce natural pigment-associated metabolites under different nutritional conditions. Forty-five fungal isolates were screened in solid media and subsequently cultivated in submerged fermentation using three media: potato dextrose broth supplemented with yeast extract (BD + YE); malt extract broth (ME); and yeast extract–sucrose broth supplemented with magnesium sulfate (YES). Among the 39 pigment-producing isolates, seven were selected for further investigation. Sucrose favored the highest absorbance values of pigment extracts, particularly for isolates identified as Talaromyces amestolkiae. In addition, the extract of T. amestolkiae TA10P5-3 exhibited the highest absorbance value (6.83 abs. units at 400 nm) when cultivated in YES medium, indicating stronger chromophore-associated spectral signals. This extract also showed antimicrobial activity against Pseudomonas aeruginosa (625 μg/mL), Staphylococcus epidermidis (312 μg/mL), and Candida tropicalis (625 μg/mL). Finally, the TA10P5-3 extract presented high total phenolic content (246.30 mg GAE/g) and antioxidant activity (EC₅₀ = 5470 μg/mL). These findings highlight Amazonian freshwater fungi as promising sources of natural pigments with potential industrial applications. Full article

Rambutan peel, an abundant agro-industrial by-product, is a rich source of ellagitannins (ETs) and represents a promising substrate for the sustainable production of ellagic acid (EA) through solid-state fermentation (SSF). This study aimed to optimize EA release from rambutan peel ETs by SSF using Saccharomyces cerevisiae 227 in column reactors. We applied a central composite design (CCD) to evaluate and optimize the effects of temperature, NaCl concentration, and peptone supplementation on EA production. We also used HPLC/ESI/MS to identify and quantify EA. Maximum EA yields were obtained under central experimental conditions (treatments 15 and 16: 35 °C, 0.53 g/L NaCl, and 8 g/L peptone), reaching 8.36 ± 1.58 and 8.23 ± 0.52 mg/g, respectively. The predictive model estimated a maximum EA production of 8.29 mg/g, experimentally validated, at 34.6 °C, 0.58 g/L NaCl, and 8.26 g/L peptone, yielding 8.27 ± 0.47 mg/g. HPLC/ESI/MS analysis further confirmed EA formation and the presence of biodegradation products derived from geraniin and corilagin, indicating effective ET biotransformation. These findings establish optimized conditions for EA production from rambutan peel ETs via SSF and demonstrate the feasibility of implementing a sustainable bioprocess for the valorization of this agro-industrial residue. Full article

The increasing volume of plant-based waste generated by the agri-food sector represents both an environmental challenge and an underexploited biotechnological resource. These wastes, rich in lignocellulosic compounds, constitute a natural habitat for specialized microorganisms. The aim of this article is to provide a critical review of the potential use of such wastes—specifically straw, pomace, and manure—in two complementary ways: (1) as a specific source for isolating new microbial strains with high biodegradation capacity and plant-growth-promoting potential, and (2) as a low-cost substrate for their propagation, e.g., in solid-state fermentation processes. This dual perspective represents a novel, integrative approach, as previous reviews typically address these aspects in isolation rather than considering their synergistic potential. The article discusses the relationship between the chemical composition of selected wastes (straw, pomace, manure) and the targeted selection of desirable microbiological traits. Particular emphasis is placed on advanced, integrated approaches for assessing microbial potential, combining phenotyping (zymography, activity assays), genomics (whole-genome sequencing—WGS, identification of CAZyme genes and biosynthetic gene clusters), and metabolomics (metabolite profiling, 3D MSI imaging). The limitations of individual methods are critically evaluated, and key research gaps are identified, including the need for in situ validation of omics-based findings and the development of stable microbial consortia with predictable performance under variable environmental conditions. These gaps are discussed in the broader context of circular bioeconomy and sustainable agriculture, highlighting the strategic relevance of integrating waste valorization with microbiome-based biotechnological innovations. Full article

Recent evidence highlights the therapeutic potential of Astragali radix-Huaier fermentation products for hyperuricemia treatment, although the dynamics of the fermentation process remain poorly understood. This study employed high-resolution mass spectrometry and untargeted metabolomics for real-time monitoring of chemical components and hypouricemic activity throughout fermentation. The results revealed significant alterations in the chemical composition, with distinct sample separations observed on days 7, 14, 21, and 28. A total of 33 differential components were identified, including 20 flavonoids and 13 saponins, eight of which showed notable changes. Polysaccharides and saponins were found to correlate positively with the uric acid-lowering effect. On day 21, the levels of total polysaccharides and cycloastragenol-6-glucoside, a saponin derivative, peaked, coinciding with the highest hypouricemic activity of the Astragalus fungal fermentation products. This study provides the first evidence of dynamic changes in the chemical profile and pharmacological activity of Astragali radix-Huaier during fermentation, paving the way for optimizing fermentation processes and developing medicinal and dietary products based on Astragali radix. Full article

Sea buckthorn (Hippophae rhamnoides L.) leaves are rich in nutrients and bioactive constituents, with great potential for fermented tea development. It has been demonstrated that Fuzhuan brick tea processing can improve sea buckthorn leaf tea flavor, but the underlying microbial succession remains unexplored. Therefore, we characterized the dynamic succession and interrelationships of bacterial and fungal communities via Illumina NovaSeq 6000 sequencing. β-diversity analysis revealed successive shifts in microbial community structure, with fungal communities changing mainly in the early stage and bacterial communities varying more in the late stage of fermentation. The relative abundance of Pseudomonas, a genus frequently associated with flavor formation and tea quality, increased steadily. Fungal taxonomic analysis revealed that the genus Aspergillus, particularly the species Aspergillus chevalieri, remained dominant throughout the fermentation process. Linear discriminant analysis effect size indicated an enrichment of microbial taxa typical of fermentation, accompanied by a relative reduction in putative opportunistic microbes. Additionally, Aspergillus exhibited significant negative correlations with five key differentially abundant bacterial genera. Interestingly, microbial co-occurrence networks suggested an overall tendency toward coexistence rather than mutual exclusion between the bacterial and fungal communities. This work provides a theoretical foundation for the development of novel fermented sea buckthorn leaf tea products. Full article

This study evaluated the impact of lactic acid fermentation on microbiological and nutritional quality, bioactive compound profile, and bioactive properties of mashed navy beans (MNB). Lactic Acid Bacteria (LAB) viability and microbiological quality of fermented mashed navy beans (FMNBs) were maintained for up to 28 days at 4 °C. Fermentation improved protein quality while reducing trypsin inhibitor activity. Additionally, fermentation enhanced the extractability of phenolic compounds, especially of bound forms. Proteolytic activity during fermentation generated low-molecular-weight peptides enriched in hydrophobic residues. Although antioxidant capacity remained comparable between samples, fermented samples exhibited higher angiotensin-converting enzyme inhibitory (ACE-I) activity (IC₅₀ ACE-I = 0.635 ± 0.043 and 0.413 ± 0.002 mg solids mL⁻¹ for MNBs and FMNBs, respectively). Simulated gastrointestinal digestion enhanced both antioxidant (ABTS•+) and antihypertensive potential. ECA-I inhibition was higher in the fermented sample dialysates (D), with IC₅₀ values of 0.160 ± 0.005 and 0.117 ± 0.003 mg solids mL⁻¹ for MNB-D and FMNB-D, respectively, due to the increased dialyzability of phenolic compounds and the presence of hydrophobic low-molecular-weight peptides in FMNB-D. Furthermore, FMNB-D exhibited competitive ACE-I inhibition. These findings demonstrate that lactic fermentation is an effective strategy to enhance the nutritional and health-promoting properties of legume-based foods. Full article

This study evaluated the effects of feed fermented with Lactobacillus acidophilus and Lacticaseibacillus rhamnosus on the growth performance and intestinal condition of the juvenile rainbow trout Oncorhynchus mykiss. Three fermentation times (3, 6, and 9 h) were compared against a non-fermented control diet. The experimental design followed a randomized block scheme, with four treatments and four replicates. Juvenile rainbow trout (22.2 ± 0.9 g) were distributed among 16 tanks (500 L) connected to a recirculation system at a density of 15 fish per tank. A commercial diet (45% crude protein) was fermented through solid-state fermentation. After 60 days, growth performance and intestinal condition were assessed. The microbial fermentation of extruded commercial feeds was efficient, increasing the lactic acid bacteria count and reducing pH within 6 h. Feeding fermented feeds reduced feed intake without affecting fish growth performance. Feed fermented for 3 and 6 h improved feed efficiency, and evidence of enhanced nitrogen utilization was observed. In addition, feed fermented for 6 h increased intestinal colonization by lactic acid bacteria and enhanced intestinal lipase activity. Feed fermented for 9 h showed evidence of improved intestinal condition. Overall, this study indicates that feed fermentation improves feed efficiency and intestinal condition in rainbow trout. Full article

Anaerobic digestion is a key technology for chicken manure valorization, but ammonia accumulation often causes system instability. In this study, a 100-day continuous stirred tank reactor (CSTR) experiment was conducted under mesophilic conditions to investigate the mechanisms of ammonia inhibition in chicken manure at total solids (TS) contents of 8% (T1), 12% (T2), and 16% (T3). Compared to T1, the peak TAN concentrations in T2 and T3 were 64.28% and 73.82% higher. After 100 days, pH in T2 and T3 dropped by 5.19% and 7.65% relative to T1. Volatile fatty acid (VFA) accumulation increased by 4.6- and 6.5-fold, while the TS-based methane yield decreased by 52.94% and 73.11%, respectively. Metagenomic analysis revealed the mechanisms of ammonia inhibition: high-ammonia conditions not only directly suppressed the gene abundance of methanogenic pathways but also systematically reduced the abundance of hydrolytic bacteria and acidogenic fermentative bacteria, leading to a disruption in the supply chain of methanogenic precursors, while ammonia-tolerant microbiota became competitively enriched. This study elucidates the multi-level mechanism of ammonia inhibition in high-TS chicken manure digestion at the functional gene level, providing a theoretical basis for the precise regulation of ammonia stress and improvement of system stability. Full article

Daqu is the core saccharifying and fermenting agent in Baijiu production and a pivotal factor in flavor formation. Challenges that often hinder traditional strong-flavor Daqu brewing include low enzymatic activity and insufficient aroma. Therefore, we have developed a novel Daqu brewing system. Furthermore, we investigated the differences in flavor profiles between traditional and novel Daqu by performing headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). We comparatively analyzed the microbial communities, metabolic functions, and flavor compositions in the two Daqu types via absolute quantitative metagenomics. Functional microorganisms were significantly enriched in the novel Daqu, which exhibited enhanced carbohydrate metabolism and a highly robust acidic environment owing to the fostering of core functional genera such as Aspergillus, Saccharomyces, and Pediococcus. This significantly increased the aldehyde and organic acid levels, which resulted in pronounced aldehydic and acidic sensory characteristics. Carbohydrate-Active EnZyme (CAZy) profiling confirmed the significantly elevated abundance of glycoside hydrolases (GHs) and glycosyltransferases (GTs) in novel Daqu, which improved starch bioconversion and synthesis of flavor precursors. Thus, this study shows that novel Daqu promotes ethanol accumulation and the synthesis of flavor compounds like acetals by strengthening the core microbiota and metabolic networks. These findings provide a theoretical foundation for enriching the aromatic complexity of Baijiu. Full article