需要基于微生物的生态友好型生物物质来保护作物免受植物病原性真菌的侵害,并取代导致严重环境问题的有毒化学杀真菌剂。本研究筛选了土壤抗真菌链霉菌菌株,产生丰富的,多样化,和土壤环境中有价值的生物活性代谢物。对大约2,400个链霉菌属菌株进行基于生物测定的抗真菌筛选,从而分离出149个菌株作为初步的抗真菌生产者。一种对白色念珠菌和尖孢镰刀菌表现出最有效的抗真菌活性的链霉菌菌株被鉴定为推定的抗植物病原土壤分离物,与rubrisoli链霉菌高度同源(命名为S.rubrisoliInha501)。体外抗真菌试验,锅测试,和针对各种植物病原真菌的田间试验证实,S.rubrisoliInha501是一种潜在的新型植物病原杀菌剂生产者,可保护土壤环境中的各种作物。rubrisoliInha501的全基因组测序和抗SMASH基因组挖掘方法揭示了染色体中大约150kb的多烯生物合成基因簇(BGC)。目标化合物的分离及其BGC分析证实,在S.rubrisoliInha501中表现出抗植物病原活性的巨型线性多烯化合物与先前报道的化合物高度同源,这些结果表明,基于生物测定法的新型抗真菌链霉菌菌株的筛选,然后对其基因组进行目标化合物BGC表征,将是分离新型候选植物病原性杀菌剂的有效方法,该杀菌剂可以在土壤环境中保护作物。
Microbial-based eco-friendly biological substances are needed to protect crops from phytopathogenic fungi and replace toxic chemical fungicides that cause serious environmental issues. This study screened for soil antifungal Streptomyces strains, which produce rich, diverse, and valuable bioactive metabolites in the soil environment. Bioassay-based antifungal screening of approximately 2,400 Streptomyces strains led to the isolation of 149 strains as tentative antifungal producers. One Streptomyces strain showing the most potent antifungal activities against Candida albicans and Fusarium oxysporum was identified as a putative anti-phytopathogenic soil isolate that is highly homologous to Streptomyces rubrisoli (named S. rubrisoli Inha 501). An in vitro antifungal assay, pot-test, and field-test against various phytopathogenic fungi confirmed that S. rubrisoli Inha 501 is a potential novel phytopathogenic fungicide producer to protect various crops in the soil environment. Whole-genome sequencing of S. rubrisoli Inha 501 and an anti-SMASH genome mining approach revealed an approximately 150-kb polyene biosynthetic gene cluster (BGC) in the chromosome. The target compound isolation and its BGC analysis confirmed that the giant linear polyene compound exhibiting the anti-phytopathogenic activity in S. rubrisoli Inha 501 was highly homologous to the previously reported compound, neotetrafibricin A. These results suggest that a bioassay-based screening of a novel antifungal Streptomyces strain followed by its genome mining for target compound BGC characterization would be an efficient approach to isolating a novel candidate phytopathogenic fungicide that can protect crops in the soil environment.