Inflammatory bowel disease is a significant health concern not only in humans but also in companion animals and livestock, where it manifests as chronic diarrhoea, abdominal pain, and mucosal injury. Probiotics have gained increasing attention as potential therapeutic agents due to their immunomodulatory effects and ability to restore intestinal homeostasis. This study investigated the therapeutic efficacy of Bacillus coagulans and Lactobacillus acidophilus in an acetic acid-induced ulcerative colitis model in Wistar rats. Forty male rats were randomly assigned to control, colitis, mesalazine, B. coagulans, and L. acidophilus treatment groups. Disease severity was evaluated by macroscopic and histopathological scoring, colon length and weight, pro-inflammatory cytokine levels (IL-1β, IL-17), and inflammasome-associated gene expression (NLRP3, Caspase-1, IL-18, TNF-α). The results showed that colitis induction significantly increased pro-inflammatory cytokine expression and histological damage compared with controls. Both probiotics markedly reduced inflammatory markers, improved colon morphology, and attenuated inflammasome activation. Their protective effects were comparable to mesalazine, the standard treatment. These findings suggest that B. coagulans and L. acidophilus can serve as effective adjunct therapies for ulcerative colitis in veterinary practice, with potential translational applications for companion animals and livestock.

Bacilli have become one of the most commercially significant groups of microorganisms used in agricultural biocontrol products in Brazil. Their ability to form endospores and produce a wide range of metabolites allows them to control plant diseases, promote plant growth, and alleviate stress, supporting their extensive adoption in crop protection systems. This study analyzes the Brazilian market for Bacillus-based products used in plant disease management and summarizes their mechanisms of action. Data on commercial registrations, active strains, product formulations, and target diseases were compiled from Brazilian national regulatory databases. Market indicators, such as potential area treated (PAT) and turnover, were estimated using structured agricultural surveys conducted across Brazil during the 2019/2020 and 2024/2025 crop seasons, the latter encompassing more than 16,000 interviews with farmers and agricultural managers. By December/2025, 297 Bacillus-based products containing 126 strains were commercialized in Brazil, with Bacillus amyloliquefaciens, B. subtilis, B. velezensis, and B. pumilus being the most prominent species. These products are applied via seed treatment, soil drenching, furrow, and foliar spraying to manage fungal, bacterial, and nematode diseases. During the analyzed period, PAT increased from 7.5 to 37.2 million hectares (391% growth) and turnover increased from US$114.31 to US$403.17 million (252% growth). Currently, Bacillus-based products accounted for approximately 48% of the Brazilian biological control market, highlighting the prevalence of this genus in the sector. Overall, these results demonstrate how advances in microbial biotechnology, regulatory development, and farmer adoption have positioned Bacillus spp. as key components of the rapidly expanding biocontrol industry.

Tobacco root rot is a destructive soil-borne disease that constrains sustainable tobacco production in Yunnan. Fusarium oxysporum and Fusarium solani species complex are currently considered the principal pathogens associated with this disease. Therefore, effective biocontrol agents are needed, and understanding their pathogen-side modes of action is essential for improving biological management strategies. This study screened 100 bacterial strains isolated from the tobacco rhizosphere using plate confrontation assays and identified A5 as a broad-spectrum antagonistic strain. A5 consistently inhibited four tobacco root rot-associated Fusarium species, with hyphal growth inhibition rates of 63.31%, 59.42%, 69.64%, and 68.82%, respectively. Phylogenetic analyses of 16S rRNA and gyrB sequences placed A5 close to Bacillus aerophilus, supporting its classification as a B. aerophilus-related biocontrol candidate. To investigate the fungal response to A5, F. solani was exposed to 10% sterile A5 fermentation supernatant and analyzed using transcriptomic sequencing. GO and KEGG enrichment analyses showed differentially expressed genes (DEGs) involved in UDP-N-acetylglucosamine biosynthesis and associated cell wall precursor metabolic processes. Because F. oxysporum has a more established genetic manipulation system in tobacco root rot research, this species was used for downstream functional validation. RT-qPCR confirmed the significant expression responses of FOXG_19023, FOXG_10443, and FOXG_12345 after the treatment with A5 supernatant. Subsequent construction of knockout mutants demonstrated that deletion of FOXG_19023 significantly restricted colony growth, suggesting that FOXG_19023 may contribute to vegetative growth of F. oxysporum, although its specific role in UDP-N-acetylglucosamine-related cell wall metabolism remains to be explored. Overall, A5 was identified as a tobacco root rot biocontrol bacterium with activity against Fusarium pathogens. These results further suggest that A5 may affect expression of genes involved in pathogen UDP-N-acetylglucosamine-related metabolism, and this response may be associated with impaired Fusarium hyphal growth. This study provides a potential biocontrol resource for sustainable tobacco root rot management and offers candidate pathogen-side targets for future studies on the molecular mechanisms underlying Bacillus-mediated suppression of Fusarium.

This study employed the predicted data mining approach (PDMA) to guide the biotransformation of scutellarin methyl ester by Bacillus megaterium tyrosinase (BmTYR). While the enzymatic conversion yielded 6-hydroxyluteolin 7-O-methylglucuronide, a known derivative, this study highlights the ability of PDMA to predict and synthesise single products with high specificity. This approach presents a valuable alternative to the extraction of bioactive compounds from traditional medicinal herbs, which inherently contain a complex mixture of secondary metabolites. It facilitates the efficient production of 6-hydroxyluteolin 7-O-methylglucuronide, circumventing the necessity for intricate extraction and purification procedures. Furthermore, this study provides the first full nuclear magnetic resonance characterisation of 6-hydroxyluteolin 7-O-methylglucuronide. The compound exhibited potent antioxidant activity and also demonstrated anti-inflammatory properties. The study demonstrates the potential of PDMA to facilitate targeted biotransformation of known compounds for the development of bioactive products with potential biomedical applications.

Magnetic nanoparticles (NPs) are maintained in the body for a significantly longer duration than small molecule antibiotics, potentially facilitating prolonged therapeutic effects. In this study, a novel nanoantibiotic formulation (l-glu-Fe3O4-Amp NPs) was prepared, and its antibacterial efficacy was evaluated. For this purpose, l-glutamic acid (l-glu) was used for surface modification of iron oxide nanoparticles (Fe3O4 NPs), and ampicillin (Amp) was then conjugated l-glu-Fe3O4 NPs structure. Fourier transform infrared analyses revealed that the final nanoantibiotic formulation l-glu-Fe3O4-Amp NPs was successfully prepared. The size distribution of the formulation was determined to be 164 nm by ZETAsizer. It exhibited a controlled drug release profile over a certain period of time, with a slightly increased release and then exhibited a stable profile. Agar well diffusion assay and the LIVE/DEAD BacLight fluorescent assay showed that the formulation had an antibacterial effectiveness against both Bacillus cereus and Staphylococcus aureus. The formulation has a lower minimal inhibitory concentration value against S. aureus. It significantly increased the accumulation of reactive oxygen species in both bacteria when compared with the Amp group. Its cellular uptake and bacterial interaction were confirmed by confocal and transmission electron microscopy images. The in vitro assay revealed that this formulation is nontoxic to fibroblast cells. This study highlights the potential of l-glu-Fe3O4-Amp NPs conjugate as a potentially effective antibacterial agent. This is the first report on the use of l-glu as a surface modifier of Fe3O4 NPs and Amp. Use of l-glu increases the drug-carrying capacity of NPs and reduces the possible side effects of Amp.

Carrot production regions worldwide incur enormous annual economic losses due to postharvest white mold caused by Sclerotinia sclerotiorum. Biological control is a promising approach for controlling postharvest pathogens. This study investigated the biocontrol efficacy of using Bacillus velezensis JR4 against Sclerotinia rot and its potential mechanisms of action. The results showed that the JR4 strain achieved 91.1% inhibition of S. sclerotiorum in a dual-culture assay. B. velezensis JR4 was able to produce extracellular enzymes such as protease, cellulase, and chitinase. Applying JR4 bacterial suspension at 1 × 10[8] CFU mL[- 1] on postharvest carrots infected with the pathogen reduced rot incidence by 65.4% and lesion length by 80.6% on day 5. The same concentration increased the levels of total phenolics and total flavonoids, as well as the activity of defense-related enzymes, including peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL). It also increased the expression of three defense-related genes in postharvest carrots over four days. Compared to untreated carrots, it exhibited lower levels of cell membrane permeability, malondialdehyde (MDA), superoxide anion (O2[-]), and hydrogen peroxide (H2O2). Furthermore, the cell-free culture filtrate of JR4 showed minimal to no toxicity on WI-38 and Vero cells across all concentrations. The results suggest that B. velezensis JR4 could be an effective and sustainable biocontrol agent for controlling white mold in postharvest carrots. However, further safety assessments are needed for its successful application.

In this study, Cinnamomum cassia bark essential oil (CEO) was extracted with a yield of 2.51% and characterised by its organoleptic properties, physicochemical characteristics, and gas chromatography-mass spectrometry (GC-MS) profiling. Seven phytoconstituents were identified, with (E)-cinnamaldehyde predominating (87.14%). CEO inhibited Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853, with inhibition zones of 16.0 ± 1.0-47.0 ± 1.0 mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 0.52-1.04 and 0.52-2.08 mg/mL, respectively, with greater susceptibility observed among the gram-positive strains. Antifungal evaluation revealed potent activity against Alternaria alternata and moderate activity against Aspergillus niger, with direct-contact exposure showing greater inhibition of As. niger than vapour-phase treatment. Molecular docking identified coumarin, a minor constituent, as exhibiting the strongest predicted binding, with binding energies of -7.7 kcal/mol against the bacterial targets TEM-1 β-lactamase and D-alanine:D-alanine ligase, and -7.0 kcal/mol against tyrosyl-tRNA synthetase. Coumarin also showed favorable predicted binding to the fungal targets cytochrome P450 51B (CYP51B) and epoxide hydrolase. These findings support the potential of CEO as a natural antimicrobial preservative, although further validation in real food systems is required.

Astragalus mongholicus is one of the most commonly traditional Chinese herbal medicines in China and other Asian countries. However, the root rot disease caused by Fusarium oxysporum can severely reduce root yield and quality, resulting in significant large economic losses. Although biological control has attracted widespread attention due to its safety, environmental friendliness and sustainability, the biocontrol efficiency and potential mechanism of Bacillus velezensis against root rot of A. mongholicus have been rarely investigated. In the present study, a rhizosphere bacterium GNB3-7 was isolated from the rhizosphere soil of wild A. mongholicus and possessed the strong broad-spectrum antagonistic activity on multiple pathogenic fungi, which was identified as B. velezensis on the basis of whole-genome sequence analyses. Further genomic analyses revealed that the B. velezensis GNB3-7 has 12 biosynthetic gene clusters encoding antifungal secondary metabolites (e.g., surfactin, bacillibactin, bacilysin). In addition, a total of 36 volatile organic compounds (VOCs) were detected by GC-MS, among which benzothiazole, disulfide-dimethyl and 2-nonanone showed the strongest antifungal activities, with an inhibition rate of 99.41%, 96.87% and 92.69%, respectively. In pot experiments, the treatment rate and prevention efficiency of B. velezensis GNB3-7 against A. mongholicus root rot achieved 44.44% and 72.22%, respectively. Notably, the genes involved in plant induced systemic resistance (ISR, e.g., AmNPR1, AmCHI2 and AmCOI1) were significantly up-regulated in treatment and prevention plants, indicating the activation of ISR in A. mongholicus. These results indicated that B. velezensis GNB3-7 could efficiently control root rot by synergistic action involving the production of metabolites and VOCs, activation of plant ISR, which deepens our understanding on the biocontrol mechanism of B. velezensis against root rot in medicinal plant A. mongholicus.

This study explores the bioinorganic potential of selenium nanoparticles (SeNPs) biosynthesized by Bacillus sp. (AKS_bp1, PQ824612) in mitigating hexavalent chromium [Cr(VI)] toxicity in chickpea (Cicer arietinum L.). SeNPs were produced via microbial reduction of sodium selenite and characterized by nanoscale size (~ 100-150 nm), negative surface charge (- 20 mV), and biomolecular capping. Under controlled hydroponic Cr(VI) exposure (0-100 ppm), SeNP treatment significantly reduced Cr accumulation in plant tissues, with decreases of 24% in roots and 45% in shoots, indicating restricted translocation and improved metal homeostasis. This suggests a Se-mediated modulation of Cr mobility within the plant system. At the physiological and biochemical levels, SeNPs alleviated Cr-induced oxidative stress, as evidenced by reductions in superoxide (65%) and hydrogen peroxide (52%) levels, along with enhanced antioxidant defense and photosystem II efficiency (a 21% increase in photochemical performance). Improved chlorophyll fluorescence and stomatal regulation further indicated restoration of cellular functionality under metal stress. Importantly, SeNPs exhibited intrinsic redox activity with catecholase-like catalytic behavior (kcat = 3.11 × 10[6] s[- 1]), suggesting a potential role in electron-transfer processes relevant to oxidative stress modulation. Overall, bacteriogenic SeNPs mitigate Cr(VI) toxicity through a combination of reduced metal uptake, altered intracellular metal dynamics, and attenuation of reactive oxygen species. These findings highlight the bioinorganic functionality of SeNPs as redox-active nanomaterials influencing metal-plant interactions and oxidative stress pathways.

Xanthomonas campestris pv. campestris, the causal agent of black rot, is one of the most important bacterial pathogens affecting Brassicaceae crops worldwide. Its seed-borne nature, multiple routes of dissemination, and limited availability of resistant cultivars make black rot difficult to manage and underscore the importance of early and reliable pathogen detection. This review summarizes current knowledge on the epidemiology of X. campestris pv. campestris, with emphasis on advances in conventional and molecular approaches used for its detection and characterization, as well as on the currently used disease management strategies. Particular attention is given to biological control as a promising and sustainable alternative to conventional approaches. Recent studies on the use of Bacillus spp. for black rot control are discussed, with emphasis on their secondary metabolites and antimicrobial potential. Despite promising results including disease suppression, comparable to that achieved with chemical control, the translation of laboratory findings into reliable field applications remains challenging, particularly with regard to formulation and consistent efficacy under variable environmental conditions. Future research should focus on integrating current knowledge of pathogen epidemiology, diagnostics, and biological control to facilitate the development of sustainable and practically applicable strategies for black rot management in Brassica crops.

4-hydroxy-3-methyl-2-alkenylquinolines (HMAQs) belong to an emerging sub-class of naturally synthesized alkaloids with several prominent biological properties. HMAQ-7 is a novel variant recently identified in Burkholderia contaminans MS14 which was previously shown to impede normal cellular behaviors in Bacillus subtilis, including multiple colonization phenotypes such as motility, pellicle formation, and sporulation. While the list of biological and chemical characteristics among HMAQ's and related molecules is extensive, the mechanistic basis of these responses has been far more elusive. Using a combination of RNA-seq and bioinformatics, we have determined that several of the physiological defects induced by HMAQ-7 are strongly correlated with alterations in systems related to phospho-transduction. Specifically, HMAQ-7 augments gene expression in elements associated with late stationary phase growth, including those involved in phosphate assimilation and regulation of the spo0A phosphorelay. We also note that HMAQ-7 promotes dysregulated transcription of flagellar assembly genes which would normally be downregulated during late stationary phase. This study constitutes one of the first extensive investigations into an HMAQ's mode of action, providing vital insight into the ecological dynamics between B. contaminans and B. subtilis.

Biosurfactants are environmentally friendly surface-active compounds with promising applications in environmental remediation. In this study, a biosurfactant-producing bacterium, Bacillus (B.) velezensis SHB.28, was isolated from heavy metal-contaminated soil and evaluated for its ability to produce biosurfactants using date syrup as a low-cost agro-industrial substrate. Screening assays including drop-collapse (DC), oil spreading (OS), and emulsification index after 24 h E24 (%) confirmed strong biosurfactant production. Culture conditions were optimized, revealing that 30 °C, pH 6, and a C/N ratio between 10% and 20% provided optimal production. Under optimized conditions, the crude biosurfactant extract yield reached 2.16 g/L within 24 h, accompanied by a reduction in surface tension from 69 to 29.1 dyn/cm and high emulsification activity. Kinetic modeling showed that emulsification activity followed an exponential growth model (R[2] = 0.985), whereas surface tension dynamics were well described by a spike decay-plateau model (R[2] = 0.998). Structural characterization using Fourier-transform infrared spectroscopy (FTIR), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) spectroscopy revealed that the biosurfactants are surfactin- and iturin-like cyclic lipopeptides composed of a β-hydroxy fatty acid chain (C13-C15) linked to a cyclic peptide moiety. The biosurfactant exhibited a critical micelle concentration of 100 mg/L and an anionic character with a pHpzc of 5.7. Furthermore, it demonstrated high efficiency in removing heavy metals, achieving removal efficiencies of 99.88% for Fe[2+], 99.69% for Pb[2+], and 94.72% for Cu[2+], outperforming conventional surfactants such as SDS and Tween 80. These findings highlight the potential of date syrup-derived surfactin and iturin from B. velezensis SHB.28 as sustainable and efficient biosurfactants for environmental remediation and heavy metal removal applications.

Bacillus cereus sensu lato (B. cereus s.l.) is ubiquitous in soil, but the extent to which urban-adjacent soils act as reservoirs of antimicrobial-resistant and potentially toxigenic lineages remains poorly understood globally. We analysed 243 B. cereus s.l. isolates representing unique sequence types from ten urban locations worldwide. Population structure was assessed by multilocus sequence typing and phylogenetic analyses, antimicrobial susceptibility by disk diffusion and MIC determination, and the presence and expression of nheA, hblA, and cytK by PCR and qPCR. Isolates from the same locations clustered on the phylogenetic tree more frequently than expected by chance, although isolates from different regions remained widely intermingled. Selected lineages also showed significant latitudinal distributions. Antimicrobial susceptibility varied markedly among locations, with frequent ampicillin resistance and geographic differences in cumulative elevated MIC burden that were not consistently associated with local phylogenetic clustering. These patterns may reflect region-specific anthropogenic selective pressures. The nheA gene was detected in all isolates, whereas hblA and cytK occurred in approximately half, and neither gene carriage nor relative expression was associated with elevated MIC burden. Urban-adjacent soils therefore harbour phylogenetically diverse B. cereus s.l. populations with widespread enterotoxin-associated genetic potential and geographically heterogeneous antimicrobial resistance.

Understanding how positive selection shapes molecular evolution at the protein level remains a major challenge, particularly in non-model species. Here, we integrated phylogenetic evidence from candidate genes evolving under lineage-specific positive selection with comparative structural and biophysical analyses to investigate patterns of molecular divergence in the Cereus fernambucensis-C. insularis clade, which occupies contrasting island and continental environments. Based on a previous branch-site analysis, five orthogroups were selected for downstream analyses. Orthologous protein structures were predicted and compared, variability hotspots were identified, pockets proximity were evaluated, and the stability effects of lineage-specific substitutions were estimated. Across orthogroups, global folds were largely conserved, whereas molecular divergence was primarily associated with localized structural variation in flexible loops and surface-exposed regions. Variability hotspots were significantly enriched near predicted cavities in several orthogroups, indicating that molecular diversification was concentrated in structurally permissive regions frequently associated with putative interaction surfaces. Stability analyses of reconstructed branch-specific substitutions revealed heterogeneous energetic effects, ranging from stabilizing to strongly destabilizing changes, while global protein architecture remained largely conserved. Together, these results suggest that evolutionary divergence in Cereus lineages is primarily associated with localized modifications of surface-accessible regions rather than large-scale structural innovation. More broadly, our findings demonstrate how integrating molecular evolutionary analyses with structural bioinformatics provides a robust framework for interpreting candidate adaptive genes in non-model organisms, while highlighting both the potential and limitations of structure-informed evolutionary inference.