Search Results (223)

The development of novel plant-based products using unconventional food matrices increases the risk of introducing mycotoxins into the food system. Biological detoxification methods, particularly those involving lactic acid bacteria (LAB), are considered sustainable and safe strategies. In this study, we screened 142 plant-derived LAB strains across 17 species for their fermentation performance and mycotoxin removal capacity during faba fermentation. Among them, 84 strains showed rapid acidification. The plating of 11 selected strains confirmed robust growth with cell densities ranging from 4 × 10⁸ to 2.18 × 10⁹ CFU/mL. Screening for aflatoxin B1 (AFB1) removal in complex medium identified several strains that could reduce AFB1 in the supernatant. However, complete toxin extraction after faba fermentation indicated that AFB1 was not enzymatically degraded. Similarly, no significant degradation of ochratoxin A or zearalenone was observed during faba fermentation. Additionally, a cell binding test with 11 selected strains showed that all strains bound AFB1, with efficiencies from about 10% to 35%. Notably, Lentilactobacillus hilgardii NFICC857 demonstrated the highest binding capacity, which has never been reported before. Our study provides preliminary insight into plant-derived LAB in mycotoxin removal. Given the vast unexplored diversity of LAB in nature, the discovery of novel strains with enhanced mycotoxin-binding capacity and potential enzymatic degradation remains promising. Full article

Naturally fermented tofu whey is a nutrient-rich byproduct of tofu production that harbors diverse lactic acid bacteria (LAB) with potential probiotic properties. However, the antioxidant mechanisms of these LAB, particularly the roles of different cellular fractions and their metabolic basis, remain unclear. This study aimed to isolate LAB from naturally fermented tofu whey and evaluate their antioxidant activities across cellular fractions, combining in vitro assays, 16S rDNA-based identification, metabolomic profiling, and cellular validation to elucidate the underlying mechanisms. Six LAB strains were isolated and screened for 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging capacity and environmental stress tolerance. Among the identified isolates, Lactiplantibacillus plantarum MCS1903 exhibited the highest extracellular antioxidant activity. Non-targeted metabolomic analysis of cell-free supernatant revealed distinct metabolic profiles compared with the MRS control, with significant enrichment of antioxidant-related metabolites and pathways. In Caco-2 cells, MCS1903 supernatant (<5%, v/v) showed no significant cytotoxicity and effectively alleviated H₂O₂-induced oxidative stress by modulating the Nrf2/Keap1-HO-1 signaling pathway. These findings indicate that tofu whey is a valuable source of functional LAB, and MCS1903 represents a promising candidate for probiotic and functional food applications, supporting the valorization of tofu whey and development of natural antioxidant probiotics derived from fermented food byproducts. Full article

Baijiu distillers’ grains (BDG), a major fermented cereal by-product of baijiu production, represent an underutilized source of structurally modified dietary fiber with potential value for functional food development. Here, we found that BDG-derived dietary fiber (BDG-DF), mainly composed of mannose (34.83 ± 0.38%) and xylose (35.14 ± 0.25%), promoted short-chain fatty acid production during in vitro fermentation, and its fermentation supernatants reduced IL-1β and TNF-α levels and modestly decreased IL-6 production in a Caco-2/HepG2 co-culture model. In T2D mice, BDG-DF improved glucose tolerance, with high-dose BDG-DF reducing the OGTT area under the curve by 12.4% compared with the T2D group, and alleviated hepatic steatosis. These effects were accompanied by enrichment of Akkermansia and Bifidobacterium and remodeling of bile acid profiles. High-dose BDG-DF was also associated with elevated CA and CDCA levels, altered TGR5/GLP-1 signaling, increased hepatic FXR expression, and reduced CYP7A1 expression. Integrated hepatic proteomics and metabolomics further indicated that BDG-DF was associated with changes in unsaturated fatty acid biosynthesis and PPAR-γ-related metabolic signaling. Overall, these findings suggest that BDG-DF may improve glucose–lipid homeostasis in association with gut microbiota and bile acid remodeling and hepatic PPAR-γ-related metabolic signaling. Full article

Lactic acid bacteria (LAB) have been widely utilized in the production of fermented foods worldwide due to their well-established health-promoting benefits for both humans and animals. In addition to their nutritional value, LAB exhibit antagonistic activity against foodborne pathogens, particularly Salmonella spp., which are commonly associated with livestock and animal production systems. LAB exert a range of biological effects that can inhibit the growth of Salmonella and modulate its virulence. In the present study, the antagonistic potential of Weissella confusa WM36 was evaluated based on its ability to inhibit S. Typhimurium growth, disrupt biofilm formation, and suppress the expression of virulence-associated genes. A preliminary safety assessment of W. confusa WM36 was conducted through hemolytic activity and antibiotic susceptibility profiling. In addition, the biofunctional properties of its cell-free supernatant (CFS), herein referred to as postbiotic metabolites, were investigated with a particular focus on antioxidant activity. Experimental results demonstrated that W. confusa WM36 and its CFS at 40% (v/v) achieved a complete reduction (100%) of S. Typhimurium cell counts within 6 to 12 h of treatment. Furthermore, CFS at 20% and 40% (v/v) significantly impaired biofilm formation, while treatment with 20% (v/v) CFS markedly downregulated the expression of key virulence genes. The strain WM36 exhibited α-hemolytic activity and showed susceptibility to most of the antibiotics tested, although resistance to ceftriaxone and trimethoprim–sulfamethoxazole was observed. These findings provide preliminary information regarding its safety characteristics; however, further molecular and in vivo investigations are required to comprehensively evaluate its safety for practical applications. Additionally, the CFS exhibited notable antioxidant activity, with DPPH radical scavenging capacity of 8.90 ± 0.06 mM Trolox equivalents and ABTS radical scavenging power of 13.10 ± 1.42 mM Trolox equivalents. Collectively, these findings highlight the potential of W. confusa WM36 and its postbiotic metabolites as promising biocontrol and functional agents against S. Typhimurium, while further safety validation remains necessary. Full article

Indole-3-acetic acid (IAA) is an essential phytohormone that regulates several tropic responses in plants and serves as signaling molecule in plant–bacteria interactions. In this study, a high indolic-compound-producing actinobacterial strain, designated OP15, was isolated from the roots of Opuntia ficus-indica as an endophyte and identified as a member of the Streptomyces genus based on 16S rRNA gene sequence analysis. Synthetic dairy wastewater (SDWW) was used as a low-cost fermentation substrate for the production of IAA-equivalent compounds, providing a sustainable approach that links microbial metabolite production with agro-industrial waste valorization. Fermentation conditions were optimized using a Box–Behnken design coupled with response surface methodology. To address model overfitting, a backward elimination procedure was applied, yielding a reduced statistical model (R² = 0.658, adjusted R² = 0.628, predicted R² = 0.583) with adequate predictive performance. Under the optimized conditions (1 g/L NaCl, 1 g/L L-tryptophan, 100% SDWW, 7.5% inoculum, 4.5 days), the model predicted a maximum response of 278.2 µg/mL (95% prediction interval: 230.0–326.4 µg/mL). Experimental validation yielded a response of 296.838 µg/mL, falling within the prediction interval and confirming the model’s reliability within the experimental domain. This agreement supports the model’s utility for process optimization within the experimental domain. In addition, treatment of wheat seeds with the culture supernatant of OP15 isolate significantly (p < 0.05) promoted root length and root dry weight. Overall, these findings highlight the potential of the OP15 strain for the sustainable production of IAA-equivalent compounds using SDWW and support the valorization of dairy effluents as low-cost substrates for biotechnological applications. Full article

Background/Objectives: Plant-derived soluble fibers are being explored as sustainable prebiotic ingredients; however, tropical legumes such as Leucaena leucocephala remain understudied. This study evaluated soluble fibers from L. leucocephala seeds after simulated gastrointestinal digestion, focusing on rheological properties, microbial selectivity, metabolite production, and intestinal safety. Methods: The anatomical parts of the seed underwent INFOGEST 2.0 digestion. Soluble fibers were characterized by GC-MS monosaccharide profiling, viscosity, and SEM/EDS analyses, and were used as substrates for both probiotic and pathogenic bacteria. Fermentation supernatants were analyzed for short-chain fatty acids and lactate, and cytotoxicity was assessed using Caco-2 cells. Results: Endosperm polysaccharides exhibited high apparent viscosity (>300 cP) and pseudoplastic behavior. Monosaccharide profiles revealed the presence of galacto-oligosaccharides and arabinoxylo-oligosaccharides in the oligosaccharide fraction, and galactomannans, xylans, and arabinoxylans in the polysaccharide fraction. Polysaccharides selectively promoted the growth of Lacticaseibacillus rhamnosus GG and Bifidobacterium spp., comparable to or exceeding that of fructo-oligosaccharides (p < 0.05), while limiting pathogenic bacteria. Fermentation produced acetate and lactate concentrations of >4500 ppm and >1000 ppm, respectively. Caco-2 viability remained >90% across all treatments. Conclusions: Compartment-resolved analysis identified the endosperm as the principal source of digestion-resistant viscous fiber, selectively fermented by probiotic bacteria at levels matching or exceeding fructo-oligosaccharides. These findings position L. leucocephala endosperm fiber as a candidate prebiotic substrate, warranting further preclinical evaluation. Full article

Plant extracts and microbiological supernatants were subjected to qualitative and compositional analyses to characterize their bioactive profiles and assess their potential agricultural applications. The garlic (Allium sativum) extract was rich in allicin and selected free amino acids, contained betulin as the dominant triterpene, and displayed a favorable elemental profile with high levels of potassium, phosphorus, sulfur, calcium, and magnesium, with no detectable heavy metals. Detectable amounts of B-group vitamins and vitamin E isoforms were also identified. Qualitative phytochemical screening confirmed the presence of saponins and flavonoids in the garlic extract. The Jerusalem artichoke (Helianthus tuberosus) extract exhibited a significantly higher total phenolic content compared to the garlic extract, with qualitative analysis confirming the presence of saponins, tannins, and flavonoids, suggesting a broader spectrum of bioactive compounds. The two bacterial supernatants were characterized by HPLC analysis and differed in their metabolic profiles: the Enterobacter sp. fermentation broth contained glycerol, 2,3-butanediol, and acetic acid, while the Paenibacillus sp. supernatant additionally contained lactic acid, ethanol, and succinic acid, reflecting distinct fermentation pathways. The in vitro and greenhouse studies aimed to evaluate biological preparations for controlling wheat diseases caused by fungi of the Fusarium genus as well as diseases affecting the stem base. Plant extracts (garlic—Allium sativum, Jerusalem artichoke—Helianthus tuberosus) and supernatants (fermentation broths) obtained with the Paenibacillus and Enterobacter bacteria were tested at three concentrations. In laboratory experiments, the degree of inhibition of the growth of the mycelium of the tested fungal species was determined, while in greenhouse studies, the effectiveness in limiting the development of stem base diseases and the impact of the applied biopreparations on plant growth were evaluated. Among the plant extracts, H. tuberosus demonstrated superior antifungal activity, achieving up to 100% inhibition of R. cerealis mycelial growth at 10% concentration and reducing disease severity by 34.3% compared to the untreated control under greenhouse conditions. Paenibacillus sp. supernatant demonstrated strong in vitro antifungal activity. The results indicate that H. tuberosus extract represents a promising candidate for further field evaluation as a component of sustainable wheat protection programs. Full article

Soybean root rot, primarily caused by Fusarium oxysporum, leads to severe root decay and substantial yield losses in Glycine max. This study screened ten entomopathogenic nematode-associated symbiotic bacteria for antagonistic activity against F. oxysporum. Among them, Xenorhabdus budapestensis XH-4 exhibited the strongest in vitro inhibition, suppressing mycelial growth by more than 73%. Antifungal activity was primarily attributed to extracellular metabolites, as both fermentation broth and cell-free culture supernatant were effective, whereas bacterial cell suspensions showed no significant inhibition. In greenhouse experiments, 40% (v/v) XH-4 reduced the disease index by 75–80%, comparable to the chemical fungicide metalaxyl–hymexazol. Genome mining revealed 20 biosynthetic gene clusters encoding diverse secondary metabolites, including fabclavine, fabclavine pyrrolizixenamide A, and putrebactin/avaroferrin, which likely underpin the strain antifungal efficacy. Additionally, XH-4 enhanced soybean antioxidant capacity and activated the phenylpropanoid pathway, indicating a dual mechanism involving direct antagonism and induced systemic resistance. These findings support the development of XH-4 as an environmentally friendly biofungicide for sustainable management of soybean root rot. Full article

Miang, a traditional fermented tea produced from Camellia sinensis var. assamica, is of notable cultural and socio-economic relevance in Northern Thailand. Traditionally, the non-filamentous fungi-based process (NFP) in western Lanna uses only young tea leaves, resulting in substantial amounts of mature leaves being discarded as agricultural waste. This study aimed to utilize the mature tea leaves by adapting the filamentous fungi growth-based process (FFP) of eastern Lanna using selected tannin-tolerant microorganisms, including Aspergillus niger MLF3, Cyberlindera rhodanensis P3, and Lactiplantibacillus pentosus A14-6. Study on fermentation dynamics and bioactive compound formation based on a 2-step fermentation process: 3-day solid-state fermentation with A. niger MLF3, followed by 7-day submerged fermentation by co-culture of C. rhodaninsis P3, and L. pentosus A14-6 in 500 mL sterile distilled water at 30 °C. Increased activities of polysaccharide-degrading enzymes and organic acids were clearly observed during solid-state fermentation, while the significant changes in polyphenol, antioxidant, and reducing sugar content in cell-free supernatant (CFS) were found after submerged fermentation. The obtained CFS shows inhibitory effects of 90 ± 2.5% and 95 ± 1.8% on α-glucosidase and α-amylase, respectively. Analysis of CFS by E-tongue and E-nose clearly indicated the influence of microbial mixture on the taste and aroma of the fermented products. These results demonstrate not only a high-yielding strategy for the effective biotransformation of mature tea leaves into functional drink products but also significant implications for reducing agricultural waste. Full article

This study investigates the degradation characteristics, pathways, and mechanisms of ochratoxin A (OTA) by Weizmannia coagulans CGMCC 9951 (W. coagulans CGMCC 9951), as well as its detoxification effect on Cornus officinalis pulp through fermentation. The strain efficiently degraded 300 ng/mL of OTA within 72 h (98% degradation) under optimal conditions of 37 °C, pH 5.0, and 180 rpm. Active degradation substances were primarily localized in the cell-free supernatant (CF). The degradation activity was significantly inhibited by heat treatment, proteinase K, EDTA, Cu²⁺, and organic reagents, suggesting an enzymatic mechanism. UHPLC-MS and MS/MS analysis indicated that OTA appears to be degraded to a product consistent with ochratoxin α (OTα). Based on homology to known OTA-degrading carboxypeptidases, the gene encoding WGU28473.1 was selected, expressed in E. coli, and confirmed to possess OTA-degrading activity. Molecular docking suggested potential interactions between the enzyme and OTA. Under optimal conditions, co-fermentation with Cornus officinalis pulp contaminated with 300 ng/mL OTA for 96 h resulted in a 74% degradation of OTA. The fermentation process increased the pulp’s sugar content and ABTS⁺ free radical scavenging capacity, reduced acidity, and improved the safety of the pulp. These findings demonstrate that W. coagulans CGMCC 9951 efficiently degrades OTA and improves pulp quality, highlighting its potential as a starter culture for detoxifying OTA-contaminated food. Full article

Foodborne diseases represent a major public health concern, particularly those associated with dairy products contaminated with Staphylococcus aureus, a pathogen capable of producing heat-stable enterotoxins. This study evaluated the potential of native lactic acid bacteria (LAB) isolated from artisanal kefir grains as natural biocontrol agents in fermented dairy foods. Kefir grains obtained from three artisanal producers were microbiologically characterized, revealing LAB as the dominant group and the absence of Enterobacteriaceae. Strains belonging mainly to the genera Lactobacillus sensu lato, Leuconostoc, and Pediococcus were isolated and exhibited differentiated metabolic profiles. Safety assessment showed no hemolytic activity and an overall susceptibility to clinically relevant antibiotics, although genus-dependent intrinsic resistance patterns were observed. Several strains displayed enzymatic activities related to carbohydrate digestion and high tolerance to simulated gastrointestinal conditions, with survival rates exceeding 90% during both gastric and intestinal phases. Neutralized cell-free supernatant (CFS) demonstrated differential inhibitory activity, with significant antagonism of S. aureus and E. coli, comparable to those of commercial reference strains. In a yogurt model system stored at 4 °C, selected Lactobacillus and Pediococcus strains induced a progressive and significant reduction in S. aureus populations, achieving complete elimination to undetectable levels in shorter times than commercial probiotic strains. Overall, these results demonstrate that native LAB from artisanal kefir grains exhibit an adequate safety and functional profile, together with strong antagonistic activity, supporting their potential application as natural protective cultures to improve the food hygiene of fermented dairy products. Full article

Lactiplantibacillus plantarum MS11, isolated from traditionally fermented yak milk in the high-altitude Gannan region of the eastern Tibetan Plateau, was investigated for its technological and functional potential in food applications. Using whole-genome sequencing combined with targeted experimental verification, this study clarified the genetic determinants and metabolic capacity associated with its production of folate, lactic acid, bacteriocin, and exopolysaccharides (EPS). The MS11 genome consists of one circular chromosome and three plasmids, totaling 3,318,231 bp with a GC content of 44.48%, and encodes 3155 predicted open reading frames. Complete biosynthetic gene clusters were identified for folate (7 genes), L-lactic acid (13 genes), bacteriocin (14 genes), and EPS (17 genes). Phenotypic assays confirmed the strain’s high metabolite productivity, including folate (0.6043 μg/mL), L-lactic acid (76.24 mg/mL), and EPS (544.2 mg/L). The cell-free fermented supernatant exhibited strong antibacterial activity against Escherichia coli, supporting the functional relevance of its bacteriocin-associated gene cluster. To the best of our knowledge, this is the integrated genomic and experimental characterization demonstrating that a L. plantarum strain originating from a unique high-altitude fermented dairy niche can concurrently synthesize high levels of folate together with multiple beneficial metabolites. The multifunctional attributes of MS11—including nutrient fortification, acidification capacity, EPS formation, and antimicrobial activity—indicate substantial promise for its application as a composite starter culture, natural bio-preservative, and nutritionally enhanced probiotic in fermented food systems. Full article

Probiotics hold considerable promise for treating and preventing inflammatory disease; however, their application is often limited by unclear anti-inflammatory mechanisms and reduced viability following lyophilization. In this study, I thoroughly evaluated the anti-inflammatory potential of Lactiplantibacillus plantarum FS4722 (L. plantarum FS4722) and substantially enhanced strain viability through optimization of the lyoprotectant formulation. Functional assays demonstrated that the fermented supernatant, heat-inactivated bacterial suspension, and cell lysate derived from L. plantarum FS4722 effectively suppressed transcription and expression of inflammatory cytokines in LPS-stimulated RAW 264.7 macrophages. The fermented supernatant exhibited the strongest inhibitory effects, surpassing the reference probiotic Lacticaseibacillus rhamnosus GG (LGG). Mechanistic investigations revealed that anti-inflammatory activity is primarily mediated via inhibition of the MAPK and NF-κB signaling pathways. Furthermore, using component screening combined with response surface methodology, the lyoprotectant formulation (10.00% trehalose, 1.00% sodium carboxymethyl cellulose, and 5.00% skim milk) was optimized, resulting in a lyophilization survival rate of 82.32% while maintaining cellular integrity; in this accelerated stability assessment, the strain retained 78.89% of its activity after 28 days of storage at 4 °C. Collectively, this study provides a robust and efficient approach for probiotic formulation while systematically elucidating the underlying anti-inflammatory mechanisms, thereby offering practical guidance for the development and clinical application of high-performance probiotic products. Full article

Celiac disease (CD) is an autoimmune disorder triggered by immunogenic gluten peptides that resist gastrointestinal digestion. The only current treatment is a strict gluten-free diet, which is challenging to maintain. Lactic acid bacteria (LAB) with specific proteolytic systems offer a promising strategy for gluten hydrolysis and potential reduction of immunogenicity. This study aims to isolate and characterize gluten-degrading LAB from traditional Spanish and Algerian dairy products. A total of 27 artisanal dairy samples were collected. LAB were isolated on MRS and Elliker agar. Gluten-degrading activity was screened using a well diffusion assay with cell-free supernatants and a spot assay with live cultures. Active isolates were identified by 16S rRNA gene sequencing. Out of 123 isolates, 40 (32.5%) were positive in the well assay, while 67 (54.5%) were positive in the spot assay, indicating the latter’s higher sensitivity for detecting cell-associated proteases. Halo diameters ranged from 6 to 16 mm. Algerian isolates exhibited significantly stronger activity (mean halo: 12.6 ± 2.1 mm) compared to Spanish isolates (10.2 ± 2.0 mm; p < 0.001). Molecular identification of the 32 most active isolates revealed the following dominant species: Lactiplantibacillus plantarum, L. pentosus, Levilactobacillus brevis, and Enterococcus faecium. This study confirms that artisanal dairy fermentations are rich sources of LAB with robust gluten-degrading potential. The superior activity of Lactiplantibacillus spp. aligns with their complex peptidase systems. The geographical variation highlights the influence of local fermentation practices. Selected strains represent excellent candidates for developing adjunct cultures to produce gluten-reduced foods and warrant further investigation as potential probiotics, pending safety and efficacy validation in vivo and in clinical studies. Full article

The conversion of lignocellulosic biomass (LCB) into biofuels is hindered by its inherent resistance and the drawbacks of conventional pretreatment, which include high cost, intensive energy use, and inhibitor formation. Here, we present a novel, one-pot bioconversion process that bypasses pretreatment by integrating cerium-doped iron oxide nanoparticles (CeFeO₄NPs) with a specialized enzyme system. The system utilizes enzyme supernatant from Penicillium janthinellum mutant EU-30, a strain developed via chemical–physical mutagenesis, which exhibits stable hemicellulase activity and a 25–30% increase in cellulase activity. The integrated approach effectively saccharified raw sugarcane bagasse (SB) within 24 h, generating the highest yields of 12.8 ± 0.5 g/L glucose and 11.54 ± 0.5 g/L xylose compared to other substrates tested. Subsequent fermentation with Saccharomyces cerevisiae yielded 13.47 g/L ethanol (1.21 g/L/h productivity) and demonstrated concurrent consumption of both hexose and pentose sugars. We propose that residual CeFe₃O₄NPs in the hydrolysate mitigate carbon catabolite inhibition, thereby increasing xylose utilization. This was attributed to the residual CeFe₃O₄NPs in the hydrolysate, which are thought to upregulate xylose-metabolism-related genes in S. cerevisiae, thereby alleviating carbon catabolite inhibition. This method offers a streamlined, economical, and sustainable platform for producing carbon-neutral bioethanol from agricultural waste, eliminating costly pretreatment and simplifying downstream processing. Full article