五株土壤细菌所产抑菌挥发性物质的生物活性评估及其应用

为研究土壤细菌所产生的抑菌挥发性物质的生物活性及应用潜力,运用固相微萃取-气相色谱-质谱联用技术对5株细菌菌株所产生的活性挥发物进行提取和鉴定,在密封盘内,通过相对标准纯品对鉴定出的各主要化合物的抑菌活性进行确证,并分别通过土壤处理和直接熏蒸处理的方式调查这些活性挥发物对黄瓜菌核病Sclerotinia sclerrotium和白粉病Sphaerotheca fuliginea的温室生防效果。 结果表明, 从5株细菌的TSB-YE培养物及TSB-YE培养基对照分别测定出21~31 个和12个化合物,包括烷烃、醛、醇、酮、脂肪酸、胺、肟、酚及杂环类化合物;糠醛、苯甲醛、1-辛醇、 1-辛烯-3-醇和3,7-二甲基-1,6-二辛烯-3-醇,2-乙基-1-己醇在0.01g的处理量下便能够完全抑制菌核病菌S.sclerotiorum的生长;灭菌土与细菌混合对菌核病的防效为28.57%~71.43%,高于只进行底部处理的防效,并且对黄瓜幼苗有促生作用;直接熏蒸使用时,挥发物能够较明显地降低被熏蒸幼苗白粉病的发生程度。

Bioactive evaluation and application of antifungal volatiles generated by five soil bacteria

To study the bioactivity and application potential of antifungal volatile organic compounds (VOCs)from soil bacteria,the volatiles generated by five bacteria were determined by SPME-GC-MS (Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry)and their bioactivity was given further confirmation with commercially available compounds in sealed plates.Further,the application of these volatile-producing bacteria for the biological control of two main diseases on cucumber caused by Sclerotinia sclerrotium and Sphaerotheca fuliginea,respectively treated by soil and direct fumigation,was investigated in greenhouse.In total,21-31 and 12 compounds were detected from bacterial TSB-YE cultures and TSB-YE medium controls,respectively,which covered a wide range of alkyl,aldehyde,alcohol,ketone,fatty acid,amine,oxime,phenol and heterocyclics.Of the 20 candidate compounds assayed for antifungal activity in sealed plates,furfural,benzaldehyde,1-octanol,1-octen-3-ol,3,7-dimethyl-1,6-octadien-3-ol,2-ethyl-1-hexanol exhibited complete inhibition against S.sclerotiorum at a lowest treatment dosage of 0.01 g.Mixing the autoclaved soil with bacteria caused a higher control effect (28.57%-71.43%)on S.sclerrotium than those of bottom layer treatments,and an obvious growth promotion of cucumber seedlings was shown.When applied directly as fumigation,these volatiles could significantly inhibit the disease severity of powdery mildew on the fumigating seedlings.