从土壤中选择性分离放线菌,并进行抗菌活性评价,以期筛选到具有潜在应用开发价值的菌株.以改良的HV培养基为分离培养基,添加萘啶酮酸、制霉菌素作为抑制剂,对从安徽、重庆、河北、湖北、江苏、吉林、山东、四川、天津、云南及德国莱比锡等地采集的45份土壤样品中的放线菌进行了选择性分离.以植物病原菌黑曲霉、棉花枯萎病菌、稻瘟病菌、辣椒疫霉、茄青枯病菌为指示菌,通过平板琼脂块初筛,并结合摇瓶复筛和盆栽防效进行评价.共选择性分离到570株放线菌;初筛显示,212个菌株代谢产物显示了抗真菌或抗细菌活性,占总菌株数量的37.2%,33个菌株代谢产物兼具抗真菌活性和抗细菌活性,占菌株数量的5.8%;摇瓶复筛显示,其中2株放线菌TJ231、TJ430发酵液对黑曲霉、棉花枯萎病菌、稻瘟病菌、辣椒疫霉、茄青枯病菌显示了强烈的抑制效果;1株放线菌TJ561发酵液对黑由霉、棉花枯萎菌、稻瘟菌、辣椒疫霉显示了强烈的抑制效果;盆栽试验表明,放线菌TJ231、TJ430、TJ561发酵液对辣椒疫霉病的保护效果分别为56.2%、87.2%、61.4 %.%The objective of the present study was to isolate actinomycetes, to study their antimicrobial activity and to determine their inhibitory effects on the growth of common phytopathogen.HV agar media supplemented with nalidixic acid and nystatin as inhibitors were applied to isolate actinomycetes from 45 soil samples collected in different ecosystems of Anhui, Chongqing, Hebei, Hubei, Jiangsu, Jilin, Shandong, Sichuan, Tianjin and Yunnan provinces and Leipzig (Germany).The isolates were rapidly tested for antagonistic activity against Aspergillus niger, Fusarium oxysporum f.sp.vasinfectum, Magnaporthe grisea, Phytophthora capsici and Ralstonia solanacearum by agar block screening method in petri dishes.Isolates had broad-spectrum antimicrobial activity were tested further for antiphytopathogenic activity using well diffusion in vitro.In addition, the strains with potent antimicrobial activity were tested against the infection of Phytophthora capsici in Capsicum frutescens in vivo.A total of 570 actinomycetes colonies were obtained.of all the isolates, about 37.19％ showed antagonistic activity against fungal or bacterial plant pathogens, and about 5.79％ showed antagonistic activity against both fungal and bacterial plant pathogens.Three isolates with potent antimicrobial activity were obtained by well diffusion in vitro.In addition, the 3 isolates with potent antiphytopathogenic activity suppressed the infection of Phytophthora capsici in Capsicum frutescens in vivo were 56.22％, 87.22％ and 61.43％, respectively.The study showed that these actinomycetes were an important group for producing antimicrobial metabolites.Agar block screening method combined with well diffusion test in vitro and infection test in vivo was more effective for finding potential producers of metabolites.
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