【摘要】 为筛选新型有效的番茄灰霉病菌天然抑制产物,采用平板对峙法和菌丝生长速率法从44株采自辽宁各地的放线菌中筛选植物病原真菌拮抗放线菌,通过孢子萌发生长法和系统发育树分析番茄灰霉病菌拮抗放线菌的抑菌活性和分类地位,测试高抑菌活性菌株无菌发酵液活性物质的稳定性,并以高分辨率飞行质谱扫描鉴定稀有放线菌发酵液的抑菌产物。结果表明,筛选到13株具有抑菌活性的放线菌,其中SA32、SA33、SA37、SA39、SA45、SA51这6株菌对番茄灰霉病菌的生长及其孢子萌发有抑制效果,SA37和SA45对番茄灰霉病菌菌丝生长的抑制率分别高达75.13%和79.27%,对番茄灰霉病菌孢子萌发的抑制率分别高达86.25%和93.43%。系统发育树分析表明,SA45聚类于稀有放线菌北里孢菌属,其余5株菌均聚类于链霉菌属。对比高活性菌株SA37和SA45发酵液在-20～120℃、pH值1～14和3种酶(蛋白酶K、胰蛋白酶和胃蛋白酶)处理条件下的抑菌稳定性表明,SA45发酵液的抑菌活性和稳定性均高于SA37。高分辨率质谱分析不同溶剂提取的SA45活性物质表明,SA45发酵液中不存在已报道的活性物质。综上所述,北里孢菌SA45发酵液对番茄灰霉病菌具有高效和稳定的抑菌活性,可能存在新型抑菌物质,其菌株及发酵液具有较高的应用价值和研究价值。更多还原

【Abstract】 In order to obtain new and effective natural antifungal products against Botrytis cinerea, 44 actinomycetes collected from Liaoning province were screened for antagonistic strains with antifungal activity.The antifungal activity and taxonomic status of antagonistic actinomycetes against Botrytis cinerea were analyzed by spore germination method and phylogenetic tree construction.Comparison tests of stability of active substances were performed between the aseptic fermentation broth of strains with significant antifungal activity.The antifungal products from fermentation broth of rare actinomycetes were identified by high resolution flight mass spectrometry.The results showed that 13 antifungal actinomycetes were isolated.SA32,SA33, SA37,SA39,SA45 and SA51 had antagonistic effects against the growth and spore germination of Botrytis cinerea.The inhibition rates of SA37 and SA45 against the mycelium growth of Botrytis cinerea were 75.13% and 79.27%, and their inhibition rates against the spore germination of Botrytis cinerea were 86.25% and 93.43%,respectively.Phylogenetic analysis showed that SA45 was clustered to rare actinomycetes Kitasatospora,and the other 5 strains were clustered to the genus Streptomyces.Under the conditions of-20—120 ℃,pH 1—14 and three enzymes(protease K, trypsin and pepsin),when high-activity strains SA37 and SA45 were compared,the antifungal activity and relative stability of SA45 fermentation broth were higher than those of SA37.The bioactive substances extracted from SA45 with different solvents were detected by high-resolution mass spectrometry,and the result showed that there was no reported active substance in fermentation broth of SA45.In summary,the fermentation broth of Kitasatospora sp.SA45 has efficient and stable antifungal activity against Botrytis cinerea,may contain new antifungal compounds,and its strain and fermentation broth have high application and research value.更多还原