云南榧内生放线菌FTY2的分子鉴定及其抑菌活性

Molecular Identification and Antimicrobial Activity of Endophytic Actinomycete FTY2 Strain Isolated from Torreya Yunnanensis

为探明菌株FTY2的分类地位及其发酵液的抑菌活性,采用改进的CTAB法和抑制菌丝生长速率法对从云南榧新鲜茎叶上分离得到的1株内生放线菌FTY2进行分子鉴定及其发酵液的抑菌活性研究。结果表明:FTY2初步鉴定为链霉菌属(Streptomyces sp.)放线菌,其发酵液对小麦雪腐病菌、油菜菌核病菌、淡色生赤壳菌、腐皮镰刀菌、尖孢炭疽菌和水稻稻瘟病菌等6株植物病原真菌的EC50分别为5.90mL/L、9.48mL/L、11.56mL/L、227.19mL/L、12.35mL/L和61.87mL/L;在121℃下处理30min后,对尖孢炭疽菌的抑菌活性开始大幅下降,抑制率从93.79%(4℃)降至26.73%(121℃);不同pH处理发酵液的抑菌率基本不变,均达92%以上。

The molecular identification of FTY2,an endophytic actinomycete strain isolated from fresh stems and leaves of Torreya Yunnanensis was analyzed by the improved CTAB method, and the antibacterial activity of its fermentation liquor was determined by the inhibiting mycelium growth rate method to study taxonomic status of FTY2 strain and antibacterial activity of the fermentation liquor.The results showed that FTY2 strain is identified as Streptomyces actinomycetes （Streptomyces sp）,and EC50 of the fermentation liquor against Typhla incarnata ,Sclerotinia sclerotiorum ,Bionectria ochroleuca , Fusarium solani , Colletotrichum acutatum and Pyricularia oryzae is 5.90 mL/L, 9.48 mL/L, 11.56 mL/L,227.19 mL/L, 12.35 mL/L and 61.87 mL/L separately.The inhibition rate of the fermentation liquor treated for 30 min at 121 ℃ against Colletotrichum acutatum decreases from 93.79%（4℃）to 26.73% （121℃）.The antibacterial rate of the fermentation liquors treated with different pH condition still is above 92%.