Alam Jahangir, Olofintila Oluwakemisola E, Moen Francesco S, Noel Zachary A, Liles Mark R, Goodwin Douglas C
Department of Chemistry and Biochemistry, Auburn University, Auburn, AL, United States.
Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.
Front Microbiol. 2025 Aug 29;16:1636481. doi: 10.3389/fmicb.2025.1636481. eCollection 2025.
We evaluated 284 strains from 15 species across five genera in the Phylum Bacillota (, , , , and ) for antibiosis activity against the pathogenic oomycete, . Fifty-eight strains were strong inhibitors, while 41 and 185 were weak and noninhibitors, respectively. Only strains were strong inhibitors, and inhibitory metabolites were most frequently (55 of 58 strains) expressed from five species (, , and ). Strongly inhibitory strains from (all) and (all but one) were also strong inhibitors of the fungal pathogens , , and ; therefore, these strains were designated as . The strong inhibitors from , , and strains only weakly inhibited did not inhibit or ; therefore, these strains were designated as . Lipopeptide-encoding biosynthetic gene clusters (BGCs) were prominently represented within the five bioactive generalist species and virtually absent from the 10 non-inhibitory species. Surfactin-encoding BGCs were observed across all specialists and generalists. strains also carried a fengycin BGC, and some strains were found to encode a novel iturin and fengycin BGC. Iturin (including bacillomycin L), fengycin, and surfactin were the most commonly observed lipopeptide BGCs among the most bioactive species, and many strains contained all three. Lipopeptides from strongly inhibitory JJ334 were isolated, identified, and characterized by LC-MS. Fengycin and bacillomycin L produced strong inhibition of oomycetes and fungi as compared to surfactin. Fengycin was the strongest inhibitor among lipopeptides evaluated. Six to thirteen derivatives of each lipopeptide were observed, varying primarily in fatty acid chain length.
我们评估了芽孢杆菌门五个属（、、、和）中15个物种的284株菌株对致病卵菌的抗菌活性。58株为强抑制剂，41株和185株分别为弱抑制剂和无抑制剂。只有株为强抑制剂，抑制性代谢物最常（58株中的55株）由五个物种（、、和）表达。来自（全部）和（除一株外全部）的强抑制菌株也是真菌病原体、和的强抑制剂；因此，这些株被指定为。来自、和株的强抑制剂仅对有弱抑制作用，对或无抑制作用；因此，这些菌株被指定为。脂肽编码生物合成基因簇（BGCs）在五个具有生物活性的多能物种中显著存在，而在10个无抑制作用的物种中几乎不存在。在所有专一性和多能性物种中都观察到了编码表面活性素的BGCs。菌株还携带了丰原素BGC，并且发现一些菌株编码一种新型伊枯草菌素和丰原素BGC。伊枯草菌素（包括杆菌霉素L）、丰原素和表面活性素是生物活性最强的物种中最常观察到的脂肽BGCs，许多菌株都含有这三种。通过液相色谱-质谱联用对强抑制性菌株JJ334的脂肽进行了分离、鉴定和表征。与表面活性素相比，丰原素和杆菌霉素L对卵菌和真菌有很强的抑制作用。在评估的脂肽中，丰原素是最强的抑制剂。观察到每种脂肽有6至13种衍生物，主要在脂肪酸链长度上有所不同。
