东南极格罗夫山土壤可培养细菌的分离鉴定及其产胞外酶和抗菌活性

Exrtacellular enzyme activity and antimicrobial activity of culturable bacteria isolated from soil of Grove Mountains，East Antarctica

摘要:

摘要:【目的】获得东南极格罗夫山地区土壤中可培养细菌组成信息，分析菌株胞外水解酶产生及抗菌活性情况。【方法】稀释直接涂布平板法获得可培养细菌菌株并根据其16S rRNA 基因序列对其进行系统发育分析。平板法初步鉴定菌株的胞外酶产生情况，琼脂块法分析菌株对5 种供试菌的抗性。【结果】所有土壤样品共分离出39 株可培养细菌，分属于厚壁菌门(Firmicutes，19株，48.7%)、变形菌门(Proteobacteria，分属于α-、β-、γ-变形菌纲，共计10株，25.6%)、放线菌门(Actinobacteria，8株，20.5% )、拟杆菌门(Bacteroidetes，1株，2.6%)和异常球菌-栖热菌门(Deinococcus-Thermus，1株，2.6%)等5门20个菌属，优势菌属为芽孢杆菌(Bacillus)。不同冻存温度的土壤样品分离菌株有所不同。33株细菌具有至少一种的胞外酶活力，其中产淀粉酶的菌株最多(25株，64.1%)。6株细菌可抑制至少一种供试菌的生长。【结论】格罗夫山土壤可培养细菌组成在大分类上与南极其他地区一致，但在属的水平上有所不同。分离出的具有胞外酶活性和抗菌活性的适冷菌株为进一步开发利用南极低温酶和抗菌活性物质提供了良好的菌种资源。

Abstract:

Abstract:［Objective］To investigate the composition of culturable bacteria from soil of Grove Mountains，East Antarctica and analyze the production of extracellular hydrolytic enzymes and antibacterial and antifugal activities of these culturable bacteria.［Methods］We used spread plate method to obtain culturable bacteria.Phylogenetic relationship was analysed based on their 16S rRNA gene sequences. We used plate method and agar block method to detect the production of extracellular enzymes and antibacterial and antifungal activities of these bacteria，separately．［Results］We obtained a total of 39 isolates from all the soil samples. They belonged to 20 genera and grouped into Firmicutes，Proteobacteria，Actinobacteria，Bacteroidetes，Deinococcus-Thermus lineages，of which each group occupied 48.7%，25.6%，20.5%，2.6%，2.6% of the total，respectively．Bacillus was dominant．We isolated different strains from soil stored at different temperatures，and this may be explained as viable bacteria were different at diverse temperatures．Of the 39 isolates 33 showed the activity of producing at least one extracellular enzyme．Amylase-producing strains were the most (64.1%)，6 strains were able to inhibit the growth of at least one tested bacterium or fungus.［Conclusion］Strains with extracellular enzyme activity and antibacterial and antifungal activity would contribute to the exploration of cold-active enzymes and antibacterial (antifungal) material in Antarctica．