2026· Brazilian Journal of Biology· 0 citations· 68 references
TL;DR
Overall, these results confirm that B. amyloliquefaciens EG6.1, in its new formulation consisting of pellet fractions and sonicated culture, shows great potential as a green biocide and contributes to the development of disease management strategies, while supporting SDG’s 2 and 12.
Abstract
Abstract The soil-borne fungal pathogen Fusarium oxysporum is a major contributor to reduced agricultural productivity and degradation of agroecosystem health. Meanwhile, a molecular approach using microbial biocontrol agents offers a sustainable alternative to the use of chemical fungicides. This study aims to evaluate the potential of biosurfactant produced by Bacillus spp. in controlling Fusarium which integrated with Whole Genome Sequencing (WGS) analysis. Biosurfactant activity was screened using a hemolytic assay (qualitative), an emulsification assay and surface tension measurements (quantitative). Species identification was performed using 16S rRNA gene detection via the CTAB method. Antifungal activity was tested using swab and block methods with a completely randomized factorial design (3x3x3). The presence of biosurfactant biosynthesis gene clusters was detected using Whole Genome Sequencing (WGS) analysis. The results showed that isolates ES7.1, ESD1.6, and EG6.1 were identified as B. velezensis, B. cabrialesii, and B. amyloliquefaciens, with positive potential in producing biosurfactant compounds through indications of b-hemolysis in emulsification activity, a decrease in surface tension value > 20 mN/m, and the presence of an emulsion layer. Among the isolates, B. amyloliquefaciens EG6.1 showed the strongest antifungal activity against F. oxysporum, achieving 78% inhibition in both sonicated pellet and culture fractions. A complete genome analysis of B. amyloliquefaciens EG6.1 was performed the presence of non-ribosomal peptide synthetase (NRPS) gene clusters that encode the biosynthesis of surfactin, bacillomycin D, and fengisin, with significant potential to support antifungal activity. The presence of multiple biosynthesis clusters indicates the genetic capacity of strain EG6.1 to produce bioactive compounds with synergistic fungal inhibition mechanisms. Overall, these results confirm that B. amyloliquefaciens EG6.1, in its new formulation consisting of pellet fractions and sonicated culture, shows great potential as a green biocide and contributes to the development of disease management strategies, while supporting SDG’s 2 and 12.
In this work, genes and biosynthetic pathways linked to secondary metabolite production, biocontrol activity, and plant interactions were identified and supported the experimentally validated capability of DEF39 to protect plants from fungal diseases, highlighting the potential of genomics studies.
Irene Valenti, A. Motta, M. Saracchi et al.· BMC Genomic Data· 0 citations
Endophytic bacteria represent a promising, sustainable alternative to synthetic agrochemicals for plant disease management by actively antagonizing phytopathogens and stimulating host immune responses. Despite its traditional use as an antimicrobial remedy, Wedelia chinensis remains underexplored as a source of beneficial endophytes. This study aimed to isolate and screen endophytic bacteria from W. chinensis for their antifungal activity against Fusarium oxysporum. Among 14 endophytic isolates, Bacillus subtilis LS1-5 showed the strongest antifungal activity by dual culture assay. Its cell-free culture filtrate effectively inhibited fungal spore germination by 91.3% at a 20% concentration. Crucially, B. subtilis LS1-5 produced several extracellular enzymes, including cellulase, amylase, chitinase, pectinase, gelatinase, lipase, and protease. Furthermore, the LS1-5 strain exhibited a broad array of plant growth-promoting and environmental resilience traits. Notably, it synthesized indole-3-acetic acid (IAA) at 2.11 ± 0.27 µg/mL in an LB medium without L-tryptophan, significantly promoted a 34.19% increase in root elongation, and demonstrated remarkable tolerance to extreme conditions, including high salinity (11% NaCl) and broad pH levels ranging from 6 to 12. Additionally, volatile organic compounds (VOCs) emitted by LS1-5 significantly inhibited the severe bacterial pathogens Xanthomonas oryzae (45.83%) and Xanthomonas citri (47.99%). These findings highlight B. subtilis LS1-5 as a highly effective candidate for biological control and sustainable agricultural applications.
D. Nguyen, Dong Tang Vien, Ngoc-Minh Truong Bui et al.· IOP Conference Series: Earth...· 0 citations
The phytopathogen Fusarium oxysporum threatens global food security, necessitating sustainable biocontrol alternatives to chemical fungicides. Here, we employed an OSMAC-driven dual-layer fast screening (DLFS) approach to identify Streptomyces sp. OUC-HL1638 as a potent antagonist. Through integrated NMR-based lipopeptide signature mapping and LC-MS-assisted NRPS gene mining, we efficiently targeted and isolated two stendomycins (1 and 2). These compounds exhibited potent in vitro antifungal activity (MIC = 1 μM), outperforming hymexazol by 1000-fold, and effectively controlled F. oxysporum infection in radish seedlings and postharvest cherry tomatoes without phytotoxicity. The producing strain intrinsically balances stendomycin production with low plant toxicity and sustains production under high-salinity and alkaline conditions, indicating potential for saline-alkaline agriculture. This work establishes an efficient pipeline for green fungicide discovery and highlights the promise of stendomycins and strain OUC-HL1638 as sustainable biocontrol agents for crop protection.
Jingyi Lyu, Hu Chen, Junjie Liu et al.· Journal of Agricultural and...· 0 citations
Background/Objectives: Wheat root and crown rot, caused by Fusarium pseudograminearum, Fusarium graminearum, and Bipolaris sorokiniana, are devastating soil-borne diseases that cause substantial yield losses worldwide. Endophytic fungi are promising sources of bioactive metabolites for agricultural applications. This study aimed to isolate and characterize an endophytic fungus with antifungal activity against major wheat pathogens, identify its active compound, and investigate the underlying transcriptional response. Methods: An endophytic strain Y2 was isolated from Hedyotis diffusa leaves and identified through morphological and phylogenetic analysis based on TEF-1α and RPB2 sequences. Pathogenicity of strain Y2 was evaluated on wheat stem bases. The bioactive compound was purified by HPLC and identified by HR-ESI-MS and NMR. Antifungal activity was assessed using dual-culture and microbroth dilution assays. Transcriptomic analysis (RNA-seq) was performed on F. pseudograminearum treated with equisetin, with qRT-PCR validation of seven representative differentially expressed genes. Results: Strain Y2 was identified as Fusarium incarnatum or a closely related member of the F. incarnatum–equiseti species complex (FIESC) and confirmed to be non-pathogenic to wheat. The purified bioactive compound was characterized as equisetin, which exhibited significant antifungal activity with MIC values of 16, 32, and 64 μg/mL against F. pseudograminearum, B. sorokiniana, and F. graminearum, respectively. Transcriptomic analysis revealed that equisetin treatment induced a polarized transcriptional response in F. pseudograminearum, characterized by strong upregulation of ribosome and translation-related genes and widespread downregulation of other metabolic pathways, particularly nitrogen metabolism. qRT-PCR validation of seven representative genes confirmed the reliability of the RNA-seq data. Conclusions: Our findings demonstrate that equisetin is the active antifungal metabolite produced by F. incarnatum Y2, with potent in vitro activity against major wheat root and crown rot pathogens. The transcriptomic data provide insights into the potential mechanism of action, while the non-pathogenic nature of strain Y2 supports its biosafety. Although these results highlight equisetin as a promising lead compound for antifungal development, further in planta efficacy and safety studies are required before it can be considered for practical biocontrol.
Miao Liu, Feifan Wang, Luying Han et al.· Genes· 0 citations
The present study is the first to report the antifungal activity of bacillopeptins against Sclerotinia sclerotiorum, a fungus responsible for white mold.
Maria Luiza A. Jesus-Nicoletto, J. P. Baptista, S. Noriler et al.· Scientific Reports· 1 citation
