天漠嗜盐和耐盐细菌产淀粉酶活性及菌株多样性

采用平板水解圈法对分离自张家口天漠沙土的嗜盐和耐盐细菌（含放线菌）进行淀粉酶活性筛选，运用基于16S rRNA基因序列的分析方法对活菌株进行系统发育多样性分析.结果表明，76个受试菌株中，有34株淀粉水解酶活性呈阳性（44.7%），其中有6株具有较强的淀粉水解酶活性；系统发育分析显示34个阳性菌株类群多样性和物种多样性较高，可以归为18个物种，分属于细菌域（Bacteria）的2门（Actinobacteria，Firmicutes）2科（Streptomycetaceae，Bacillaceae）8属（Streptomyces，Bacillus，Gracilibacillus，Halobacillus，Oceanobacillus，Piscibacillus，Thalassobacillus，Virgibacillus）；产淀粉酶活性较强的6株菌均属于厚壁菌门（Firmicutes）芽孢杆菌科（Bacillaceae），分属于该科的3个属.其中菌株JSM 1684012，JSM 1684041和JSM 1685098属于芽孢杆菌属（Bacillus）；JSM 1684067和JSM 1685082属于纤长芽孢杆菌属（Gracilibacillus）；JSM 1685081属于喜盐芽孢杆菌属（Halobacillus）.以上结果说明分离自张家口天漠沙土的嗜盐和耐盐菌中存在较高比例的产淀粉酶菌株，且这些菌株具有较高的类群多样性和物种多样性.

Activity and Diversity of Halophilic and Halotolerant Amylase-Producing Bacteria Isolated from Sandy Soil from Tianmo Desert

In this study,the amylase activities of 76 halophilic and halotolerant bacteria isolated from the sandy soil samples collected from the Tianmo Desert in Zhangjiakou City,Hebei Province,China,were studied by using the plate hydrolysis spot method.The results showed that the amylase activities of 34 out of the 76 (44.7%) strains tested were observed,in which 6 strains showed relatively strong amylase activities.Then these 34 strains were submitted for 16S rRNA gene amplification and phylogenetic analysis,and the results suggested that the 34 amylase-positive strains represented 18 species,being members of 8 genera (Streptomyces,Bacillus,Gracilibacillus,Halobacillus,Oceanobacillus,Piscibacillus,Thalassobacillus,Virgibacillus) of 2 families (Streptomycetaceae,Bacillaceae) in 2 phyla (Actinobacteria,Firmicutes) of the domain Bacteria.The results also suggested that the 6 strongly amylase-positive strains all belonged to the family Bacillaceae of the phylum Firmicutes and were members of 3 genera:strains JSM 1684012,JSM 1684041 and JSM 1685098 belonged to the genus Bacillus,and strains JSM 1684067 and JSM 1685082 belonged to the genus Gracilibacillus,and strain JSM 1685081 belonged to the genus Halobacillus.In conclusion,the results presented above showed that there are a number of amylase-producing strains in halophilic and halotolerant bacteria isolated from sandy soil samples collected from the Tianmo Desert in Zhangjiakou City,Hebei Province,China,and the amylase-positive strains show abundant phylogenetic biodiversity.