海岸盐沼湿地细菌抗真菌活性研究

为了开发对植物病原真菌生长有抑制作用的药源微生物,本实验采用平板稀释法从江苏大丰盐沼湿地土壤中分离微生物,并通过菌丝块法检测这些微生物代谢产物对5种植物病原真菌生长的抑制活性,进而利用柱层析分析其活性成分;结果共分离得到235株细菌,其中好氧细菌92株,厌氧细菌143株;体外活性测试结果显示有65株至少对1种测试植物病原真菌的抑制率在30%以上,其中好氧菌39株,厌氧菌26株。从好氧和厌氧菌株中分别选取3株和1株具有不同抗菌类型的菌株进行大批发酵,用不同的方法对发酵液吸附,分离和纯化,获得抗真菌活性组分。可见,海岸盐沼湿地土壤中蕴涵着大量的细菌种群,约有28%的细菌菌株能够产生抗真菌活性物质,其中Y6、Y156和Y96的抗真菌活性物质极性较大,值得进一步开发。

Antifungal activity of bacteria isolated from coast salt marsh

The purpose of this study is to screen microorganisms with growth inhibition against plant fungal pathogens. The plate-dilution method was used to isolate the bacteria from salt marshes at Dafeng, Jiangsu. The antifungal activity of the bacterial broth filtrates against 5 phytopathogens was determined using mycelial disk method. The antifungal compositions of four active bacteria were analyzed primarily with chromatography techniques. Two hundred and thirty-five aerobic (92) and anaerobic (143) bacterial strains have been isolated from the coast salt marsh and sixty-five strains, of which 39 are aerobic and 26 are anaerobic showed greater than 30% of inhibition rate against the growth of at least one of the phytopathogenic fungi on petri dish. Three aerobic and one anaerobic strain representing four different spectra of antifungal activities were selected to do large scale fermentation. The fermentation broths were fractionated and purified with different methods resulting in some antifungal components. To be concluded, coast salt marshes are rich in bacteria;about 28% of them show potential ability to produce antifungal substances. Particularly, strain Y6 ,Y156 and Y96 are worthy to be developed because of the water soluble nature of their active substances.