猪笼草中产蛋白酶内生菌的分离及鉴定

采用研磨法分离纯化猪笼草各组织器官中的内生菌,并采用水解圈法和摇瓶发酵法分别进行初筛与复筛,对筛选出的菌株进行16SrDNA分析鉴定。结果表明:在猪笼草叶片、捕虫囊、根和茎等4种器官中共分离出25株内生菌;进一步从中筛选出2株可产胞外蛋白酶的细菌A3、L5,其中菌株A3的产酶能力较高,水解圈/菌落直径比(D/d)值为6.5,发酵液的蛋白酶活力为17.58U/mL;菌株L5的D/d值为3.0,发酵液的蛋白酶活力为15.77U/mL;16SrDNA鉴定结果表明,菌株A3、L5与芽孢杆菌属成员具有99%的同源性,其中A3是枯草芽孢杆菌(Ba-cillus subtilis),L5可能是其的新变种或新亚种。

Isolation and Identification of the Protease Producing Endophyte Bacteria from Nepenthes mirabilis

By using grinding method,we successfully separated and purified the endophyte bacteria from the surface disinfected Nepenthes mirabilis organs.Then we respectively used casein plate hydrolysis spot method and shaking flask culture method to conduct primary screening and secondary screening tests to the endophyte bacteria,following by the 16S rDNA identification method to the isolated bacteria strains.As a result,from the leaves,ampulla,roots and stems of N.mirabilis,25 endophytes were isolated,among which the A3 and L5 could produce extracellular protease.A3 had a stronger ability to produce protease:the D/d value of A3 was 6.5,and the protease activity of the fermentation broth was 17.58 U/mL;while,the D/d value of L5 was 3.0 and the protease activity of the fermentation broth was 15.77 U/mL;furthermore,both A3 and L5 showed 99% homologous to Bacillus.Between the two endophytes,A3 was the Bacilus subtilis and L5 might be one new subspecies or new varieties of the B.subtilis.