Search Results (2,471)

Abundant non-medicinal byproducts of Polygonatum sibiricum and Gentiana scabra are severely underutilized, resulting in resource waste and environmental burden. A previous study confirmed that triple-microbial co-fermentation enhances their antibacterial activity, yet the temporal metabolic mechanism and optimal process parameters remain unclear due to endpoint-only metabolomics limitations. This study aimed to optimize the staged solid-state fermentation (SSF) system for maximum antibacterial activity, verify the triple-microbial consortium’s synergistic enhancement effect, and elucidate the dynamic metabolic mechanism via time-series metabolomics. A staged SSF strategy was established: Aspergillus niger monoculture (0–48 h) followed by Bacillus subtilis and Saccharomyces cerevisiae co-culture (48–72 h). Key parameters were optimized via single-factor experiments and a Box–Behnken design. Under optimal conditions, inhibition zones against Staphylococcus aureus and Escherichia coli reached 20.8 ± 0.3 mm and 17.6 ± 0.2 mm, respectively, with a 17.5% increase in S. aureus inhibition and markedly improved E. coli inter-batch consistency. Time-series untargeted LC-MS/MS metabolomics (2681 identified metabolites) revealed a three-stage metabolic relay model driving antibacterial enhancement: 0–48 h shikimate pathway activation for phenolic precursor accumulation; 48–60 h dipeptide conversion and ABC transporter enrichment initiating antibacterial synthesis; 60–72 h metabolic flux redirected to indole alkaloid biosynthesis for complex antibacterial compound accumulation. This work provides a mechanistic paradigm for the high-value valorization of herbal byproducts, with applications in natural antibacterial agents and functional feed additives. Full article

Cellulose-derived gel films are promising matrices for the immobilization and delivery of beneficial microorganisms in sustainable plant protection. This study evaluated the effects of polymer molecular weight and chemical structure on the physicochemical properties and biocontrol performance of hydroxyethyl cellulose (HEC) films of low, medium, and high molecular weight, as well as sodium carboxymethyl cellulose (CMC-Na), loaded with Bacillus subtilis. The films were characterized in terms of morphology, swelling behavior, mechanical properties, microbial viability, and antifungal activity against Fusarium avenaceum and Alternaria solani. Increasing HEC molecular weight produced progressively denser and more homogeneous gel networks, resulting in improved structural integrity, whereas CMC-Na formed dense but less stable networks. Swelling studies at pH 4, 7, and 9 showed high water uptake for all HEC systems, with enhanced structural stability observed in high-molecular-weight films, whereas CMC-Na dissolved rapidly under all conditions. Mechanical testing further confirmed that increasing molecular weight enhanced stiffness and tensile strength but reduced flexibility. Immobilized in gel matrices, B. subtilis remained viable after 12 months of storage and rapidly reactivated after rehydration. All biohybrid films inhibited fungal growth, with stronger formulation-dependent responses against F. avenaceum than against A. solani. In general, polymer molecular weight and structure were identified as key parameters controlling network organization, hydration behavior, mechanical performance, and biological functionality. These findings highlight the potential of cellulose-derived gel matrices as tunable carriers for microbial biocontrol applications. Full article

Prophylactic antibiotic use in intensive aquaculture promotes antimicrobial resistance, necessitating the development of microbial-based interventions. This study evaluated the individual, complementary, and synergistic effects of Bacillus subtilis natto (BSN) and Lactobacillus plantarum (LP) on the physiological performance and intestinal microecology of juvenile Japanese flounder (Paralichthys olivaceus). Over a 60-day trial, juveniles (initial weight: 5.81 ± 0.03 g) received a basal diet (CON) or a diet supplemented with 10⁷ CFU/g of BSN, LP, or both (BSN+LP). The BSN+LP consortium elicited complementary improvements in final body weight (21.39 ± 0.75 g vs. 18.66 ± 0.44 g in CON) and feed conversion efficiency (p < 0.05). Transcriptomic analysis revealed synergistic upregulation of digestive proteases (trypsin, chymotrypsin). Notably, an in pro-inflammatory markers (IL-1β, TNF-α) was counterbalanced by substantial upregulation of anti-inflammatory cytokines (IL-10, 5.65-fold; TGF-β1, 4.48-fold), suggesting the induction of mucosal tolerance rather than pathological enteritis. High-throughput 16S rRNA sequencing showed that the control cohort had a potential baseline microbial, characterized by a high relative abundance of Proteobacteria. BSN+LP administration significantly altered this microbial community into a fermentative eubiosis enriched in Firmicutes and Bacteroidota. Correlation network analyses confirmed negative interaction dynamics: increased abundance of Lactobacillus, Bacteroides, and Muribaculaceae was negatively correlated with baseline pathobiont abundance. These findings indicate that co-administration of BSN and LP hypothetically enhances metabolic energy harvest via short-chain fatty acid-producing taxa, strengthens the gut–immune axis, and competitively mitigates opportunistic pathogens. Full article

The olive tree (Olea europaea L.) is one of the oldest known cultivated trees worldwide and an iconic species within the Mediterranean Basin. This study evaluated the impact of three bacterial strains, Bacillus subtilis D3, Paenibacillus tundrae M4, and Streptomyces tricolor HM10, on the mortality of the following four mite pests: Oxycenus niloticus, Tegolophus hassani, Aceria olivi, and Tetranychus urticae. B. subtilis D3 confirmed the highest efficacy, causing 91.84–85.36% mortality in laboratory tests and 88.90–84.12% in field trials after five days. In addition, P. tundrae M4 ranked second, achieving 90.49–84.26% mortality in the lab and 87.87–83.81% in the field after one week. S. tricolor HM10 produced 80.06–74.09% mortality in laboratory assays and 76.73–73.36% under the field conditions. Effects on the predatory mites Agistemus exsertus and Amblyseius swirskii were minimal, with mortality ranging from 13.28 to 18.55% in the lab work and 12.46–16.74% in the field experiment. Genome analysis of strain HM10 revealed a biosynthetic gene cluster with predicted terpenes production. Terpenes can cause chemo-osmotic stress and broad membrane-disrupting capabilities. These results highlight the promise of microbial agents for sustainable mite management and provide a foundation for further optimization of bacterial biocontrol strategies. Full article

The Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET-ATRP) of vanillin methacrylate (VMA), a bio-based methacrylic monomer derived from vanillin, was systematically studied for the first time. The reaction conditions were optimized aiming at achieving good monomer conversions while preserving the antimicrobial aldehyde functionality. Bipyridine-based catalysts showed limited effectiveness, whereas polydentate aliphatic amines displayed higher activity. Kinetic studies showed linear profiles during the early stages of the polymerization before reaching a conversion plateau accountable to the depletion of the reducing agent, as confirmed by reactivation experiments. The resulting polymer (PVMA) exhibited a glass transition temperature comparable to that of poly(styrene), emerging as a potential bio-derived alternative to fossil-based thermoplastic materials. Furthermore, preliminary in vitro tests demonstrated that PVMA has potential antimicrobial activity against both Escherichia coli (Gram-negative) and Bacillus subtilis (Gram-positive). Full article

The increasing demand for sustainable plant protection products has intensified interest in microbial biocontrol agents (BCAs). This study aimed to evaluate the antifungal activity of selected Streptomyces, Bacillus, and Trichoderma asperellum strains against phytopathogenic fungi and to assess their potential as BCAs under in vitro conditions. The antifungal activity of ten Streptomyces strains was first evaluated against Botrytis cinerea, Colletotrichum salicis, Fusarium oxysporum, and F. graminearum using a dual-culture assay. All isolates exhibited antifungal activity, with Streptomyces venezuelae MSCL 350 showing the strongest inhibition. In addition, the antifungal activity of T. asperellum MSCL 309 and three Bacillus strains was assessed against twelve Fusarium spp. isolates obtained from oats. T. asperellum demonstrated broad-spectrum inhibition, with growth inhibition ranging from 44.6% to 78.4%, primarily due to soluble metabolites, while volatile compounds showed no significant effect. Among the other tested Bacillus strains, only Bacillus subtilis MSCL 1441 exhibited antifungal activity, inhibiting all tested isolates. These results demonstrate strong strain-dependent antifungal activity and highlight T. asperellum MSCL 309, S. venezuelae MSCL 350, and B. subtilis MSCL 1441 as promising candidates for the development of environmentally friendly biocontrol agents. Full article

Naturally abundant endophytes colonize plants internally without causing harm to their host plants. Endophytes are likely to occupy the same ecological niches as phytopathogens and thus have a high potential to be effective biological control agents. Their demonstrated ability to suppress more than one plant pathogen suggests that they can offer a viable alternative to chemical fungicides and a strategy for decreasing the inoculum potential of soil-borne pathogens. Some biocontrol endophytes are also known to improve soil health and the overall health of plants. However, the results in greenhouse studies do not always translate to consistent field efficacy. In this study, the efficacy of three endophytic bacterial isolates (PRT (Bacillus subtilis), PSL (Bacillus amyloliquefaciens), and IMC8 (Bacillus thuringiesis) were evaluated against Phytophthora capsici in a field environment and compared with two commercial biological fungicides, Serenade^® (Bayer Crop Science, St Louis MO, USA) and Double Nickel^® (Certis Biologicals, Columbia, MO, USA), and water control. Plants were inoculated with the bacteria strains using seed treatment for early plant colonization before transplanting to a field infested with P. capsici. Treatments with commercial bio-fungicides followed label recommendations. Data on plant growth vigor, disease severity, number of fruits, fruit size, total yield per plant, and percent of diseased fruits displayed significant differences between the bacteria treatments. While PRT was the best treatment for most traits, followed by PSL on pepper, PSL and Double Nickel were the best treatments on tomatoes. IMC8 was best for plant vigor and larger fruit size, but with fewer fruits per plant on both crops. This study suggests bacterial isolates PRT, PSL, and IMC8 can provide additional products for growth promotion and P. capsici disease management in pepper and tomatoes. Full article

Aflatoxin B₁ (AFB₁) is a highly stable mycotoxin that can persist during conventional food processing and therefore poses a serious risk to food and feed safety. In this study, two enzymes (CotA and Prx) were heterologously expressed in Bacillus subtilis, purified by Ni–NTA affinity chromatography, and evaluated for their ability to degrade AFB₁. Both enzymes exhibited remarkable thermostability and distinct catalytic optima. CotA exhibited its highest activity at 80 °C with an AFB₁ removal of 38.4%, whereas Prx showed its highest activity at 90 °C with a removal of 82.6%. The optimal pH values were near neutral, with CotA performing best at pH 7.0 and Prx at pH 7.5, and both reactions approached maximal conversion within approximately 10 h. When the two enzymes were combined, a clear cooperative effect was observed. The mixed system achieved 91.0% AFB₁ removal at 80 °C after 10 h, with the best degradation activity occurring at a CotA to Prx ratio of 1:3. At 50 °C, neither enzyme alone caused appreciable AFB₁ degradation, but the addition of hydrogen peroxide markedly enhanced catalytic activity. Both enzymes also retained substantial activity after boiling and autoclaving. In a maize flour model, the mixed-enzyme system showed strong AFB₁ degradation capacity, and peroxide-assisted treatment further improved activity. These results establish a thermostable and peroxide-responsive enzymatic platform for AFB₁ degradation and support future development of enzyme-based detoxification strategies for food and feed applications. Product identification and toxicological validation will be needed to confirm the safety of the treated products. Full article

Mungbean (Vigna radiata) is an important cash crop, yet the production is significantly compromised by continuous cropping. Beneficial microbial inoculation offers a promising strategy to alleviate the stresses through rhizosphere modulation and host physiological reprogramming. This study evaluated the efficacy of two biological control agents, Bacillus subtilis (B. subtilis) and Trichoderma harzianum (T. harzianum), in promoting mungbean growth under continuous-cropping conditions. Both individual applications of B. subtilis and T. harzianum significantly improved plant biomass, root system architecture, and yield. Combined metagenomic and transcriptomic analyses were conducted to unravel the underlying mechanisms. According to metagenomic analysis, both B. subtilis and T. harzianum were responsible for significant changes in beta diversity without significantly affecting the alpha diversity of the rhizosphere microbial community. T. harzianum recruited Chitinophagaceae unclassified, Abditibacterium, Hydrogenophilaceae unclassified, Methylophilaceae unclassified, and Chimaeribacter, while Bs recruited Candidatus Saccharibacteria unclassified. Transcriptomic analysis indicated that T. harzianum induced more extensive transcriptional reprogramming than B. subtilis. The enrichment analysis revealed both shared and distinct responses triggered by the two treatments. These findings suggest that B. subtilis and T. harzianum alleviate continuous-cropping stress through distinct yet complementary mechanisms involving rhizosphere microbiome modulation and mungbean transcriptional reprogramming. This study provides a sustainable strategy for legume cultivation. Full article

Efficient cultivation is essential for the rose industry. Both substrate formulation and plant growth-promoting rhizobacteria (PGPR) application both critical, yet their synergistic effects remain limited. This study investigated the synergistic effects of Bacillus subtilis (Bs) and Priestia megaterium (Pm) combined with five substrate formulations on the growth physiology, photosynthetic characteristics, and soil properties of Rosa × hybrida ‘Ruby’. Two-way ANOVA revealed significant interactions between substrate and PGPR treatments for most growth and physiological indicators. Orthogonal experiments demonstrated that specific PGPR–substrate combinations significantly enhanced plant growth and photosynthetic performance of the studied cultivar, as well as soil quality. Principal component analysis and membership function analysis identified four substrate–PGPR combinations as optimal, with the T4 substrate (humus/perlite/vermiculite/coconut coir/peat/biochar = 5:1.5:1:1:1:0.5) showing the most pronounced effects. In this T4 substrate, PGPR inoculation significantly altered the rhizobacterial community structure. LEfSe analysis revealed 67 enriched microbial biomarkers—substantially more than single-strain treatments. The relative abundance of beneficial genera such as Acidibacter and Chryseotalea increased, and the combined bacterial treatment enhanced functional pathways associated with signal transduction, cell motility, and RNA processing. Compared to single-strain treatments, the combined bacterial application demonstrated superior regulatory effects on plant growth. The optimal combined treatments increased plant height by up to 42.7%, root activity by 103.0%, soluble protein content by 302.8%, and soil ammonium nitrogen by 168.8%. These findings demonstrated that tailored combinations of PGPR and cultivation substrates highlight the potential for optimizing rose cultivation and improving the rhizosphere microecological environment. Full article

Probiotics are commonly applied to maintain the balance of gut microbiota and regulate the intestinal metabolic function of companion animals. In the present study, complex probiotics (Bacillus coagulans SNZ-1969, Bacillus subtilis, and Bacillus licheniformis) were added into the basal diet of domestic cats to investigate their influence on the intestinal microbiome and metabolic characteristics. Results revealed that the alpha diversity of the gut microbiota in the probiotic group was enhanced when compared to the control group. The beta diversity of the gut microbiota was also altered by the oral consumption of the complex probiotics. Compared to the control group, the relative abundance of beneficial microbes (such as Clostridium, Bacteroides, Phocaeicola, and Ruminococcus) in the probiotic group was enhanced, while the relative abundance of opportunistic pathogens (such as Escherichia, Gallibacter, Corynebacterium) was decreased. Additionally, the intestinal metabolic characteristics of domestic cats were also changed. The metabolomic analysis identified 408 differential metabolites between the two groups, and the KEGG function pathway analysis proved that the dominant pathway related to the differential metabolites were the amino acid metabolism, lipid metabolism, carbohydrate metabolism, energy metabolism, endocrine system, digestive system, immune system, and other metabolic pathways. Spearman’s correlation analysis revealed that the beneficial microbes had positive correlations with the differential metabolites. In conclusion, the current study demonstrated that oral administration of complex probiotics could regulate overall health and well-being in domestic cats through modulating the gut microbiome and metabolic characteristics. Full article

Municipal wastewater represents an underutilized secondary biomass resource rich in organic carbon and nutrients that can be valorized through biotechnological conversion. In this study, we developed an integrated multi-microbial biorefinery platform to transform municipal wastewater into value-added biofuel via sequential bacterial treatment, microalgal biomass generation, and fungal-assisted harvesting. Wastewater was first pretreated with Bacillus subtilis to enzymatically hydrolyze complex organic substrates and enrich the medium with bioactive metabolites, including auxins and gibberellins. The conditioned wastewater was subsequently used to cultivate Chlorella vulgaris, followed by biomass recovery using Trichoderma viride pellets as a sustainable bioflocculant. The integrated consortium significantly enhanced nutrient removal efficiency and promoted algal biomass accumulation, lipid enrichment, and biodiesel productivity compared to monoculture controls. Elevated hydrolytic enzyme activities (cellulase, protease, and amylases) facilitated organic matter conversion into bioavailable substrates, while increased phytohormone levels stimulated algal growth and lipid biosynthesis. Additionally, fungal bioflocculation substantially improved biomass recovery efficiency, reducing the need for energy-intensive harvesting technologies. This work highlights the potential of a biotechnology-driven approach for integrating wastewater remediation with biofuel production. By integrating microbial metabolism, enzymatic transformation, and sustainable separation processes, the proposed biorefinery system suggests a potentially low-carbon approach for simultaneous environmental remediation and biomass valorization, although further life cycle and energy balance analyses are required to validate this aspect. Full article

Bioactive glass (BAG) S53P4 is a clinically approved bone substitute with antibacterial, osteoconductive and osteostimulatory properties. Its antibacterial effect is associated with ion release, local pH elevation and osmolality, but the precise biochemical and biophysical mode-of-action is unclear. This study investigates the antibacterial mechanism of BAG S53P4 eluates. BAG eluates, collected at 2, 4, 8, and 24 h, eradicated Staphylococcus aureus. Elemental analysis revealed an early increase in concentrations of Si and Na, a later rise in Ca, depletion of P over time and rapid loss of Mg. Membrane disturbances occurred within 5 min, evident by permeability for SYTOX, aligning with time-kill kinetics for S. aureus and Bacillus subtilis. In B. subtilis, 2h-BAG-eluate induced rapid delocalization of marker proteins for cell division and DNA repair, signaling membrane potential collapse and nucleoid condensation. Transcriptomics revealed early transcription remodeling reflecting ionic and energetic imbalance, including disruption of central metabolism, redox homeostasis, and translational stability. Scanning electron microscopy revealed severe cell surface damage and particulate deposits on S. aureus. Transmission electron microscopy showed cell envelop disruptions and cytoplasmic leakage. Energy dispersive X-ray analysis identified Si on bacterial cell surface at 4 h and intracellular accumulation in punctured, empty cells at 24 h. Overall, BAG ionic dissolution products kill bacteria through a stepwise mechanism involving membrane damage, protein delocalization and metabolic impairment, accompanied by Si deposition on bacterial surfaces and loss of Mg. This finally leads to cell wall degradation, cytoplasmic content leakage and further Si deposition on the cells and inside cell ghosts. Full article

In the sustainability framework, valorization of organic by-products as reservoirs of phytochemicals useful for human health represents a hot topic. Therefore, this study evaluated Norway spruce bark and twigs (NSB, NST), chestnut tree wood (CTW), and pomegranate fruit waste/pomace (PFW) as sources of bioactive compounds by employing green technologies. Microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), applied individually or sequentially, were optimized by modulating solvent composition, temperature, time, microwave power, and ultrasound amplitude. Hydroalcoholic extraction (50% ethanol) combined with MAE yielded the highest phenolic recovery and antioxidant activity across all matrices. PFW exhibited the highest antioxidant activity assessed through FRAP, ORAC, and DPPH assays. Phytochemical profiling by HPLC-DAD identified stilbenes in spruce extracts, ellagic acid in chestnut wood, and ellagic acid and punicalagins in pomegranate waste as major bioactive constituents. Additionally, NSB and PFW exhibited α-amylase inhibitory activity. Antimicrobial testing demonstrated dose-dependent activity against Gram-positive (Staphylococcus epidermidis and Bacillus subtilis) and Gram-negative (Pseudomonas stutzeri) strains, with PFW exhibiting the strongest inhibition and NSB displaying broad-spectrum effects. Total phenolic content changed moderately after 21 days of storage. These results demonstrate that sustainable extraction enables efficient recovery of bioactive compounds from plant by-products, supporting their further functional, dietary, and medicinal applications. Full article

Muskmelon (Cucumis melo L.) is an economically important crop that remains highly susceptible to destructive fungal diseases, including gummy stem blight, downy mildew, Fusarium wilt, and anthracnose. Although fungicides and resistant cultivars are widely used, reliance on chemical control raises concerns regarding environmental safety, food quality, and the emergence of fungicide-resistant pathogen populations. Consequently, microbial biopesticides, particularly Bacillus species, have attracted increasing attention as sustainable alternatives. In this study, muskmelon plants exhibiting leaf wilting, chlorosis, and stem yellowing were collected from Guangming Farm in Wufeng, Taichung, Taiwan, and associated pathogens were isolated from stem tissues and identified to determine the causal agent of these symptoms. In addition, the biocontrol efficacy of Bacillus subtilis strain MCLB2 against melon fruit rot, as well as its underlying mechanisms, was evaluated. Pathogenicity assays confirmed that isolate F01 was the causal agent. Based on morphological characteristics and internal transcribed spacer (ITS) sequence analysis, this isolate showed 99.8% identity to Fusarium pernambucanum URM 7559 (GenBank accession no. NR_163754), and phylogenetic analysis further placed it within the Fusarium incarnatum-equiseti species complex (FIESC). Antagonistic assays demonstrated that B. subtilis MCLB2 significantly inhibited mycelial growth and suppressed the spore germination of F. pernambucanum. In addition, culture filtrates of strain MCLB2 effectively reduced Fusarium-induced fruit rot in melon and disrupted fungal cellular respiration. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis revealed that the strain produced surfactin-family lipopeptides. In conclusion, B. subtilis MCLB2 exhibits potential as a sustainable biocontrol agent for managing Fusarium fruit rot in melon, likely through surfactin-mediated disruption of fungal cellular respiration. Full article