新疆罗布泊地区可培养嗜盐古菌多样性及其功能酶筛选

Biodiversity and functional enzymes of cultured halophilic archaeon in Lop Nur region

摘要:

摘要: 【目的】探索新疆罗布泊地区高盐环境可培养嗜盐古菌的多样性及其功能酶应用潜力。【方法】采集罗布泊地区13 份土样，用纯培养并结合基于16S rRNA 基因系统发育分析的方法来研究样品中嗜盐古菌的多样性。按系统进化树的聚类关系，挑选出一些菌株进行盐度耐受及淀粉酶、蛋白酶、酯酶的酶活检测。【结果】从13 份土样中共分离到56 株嗜盐古菌，经16S rRNA 基因克隆测序，通过MEGA 4.0构建N-J 树分析，56 株菌分布于嗜盐古菌的10 个生效发表属和5 个潜在新属。运用Shannon-Wiener 方法计算其多样性指数为1. 820。挑选17 株嗜盐古菌所测试盐浓度实验结果表明这一批嗜盐古菌的大部分生长范围在10%－35%之间，最适盐浓度在20%－25%之间。不同酶活检测结果为: 淀粉酶酶活率为70.6%，蛋白酶酶活率为35.3%，酯酶酶活率为82.4%。【结论】新疆罗布泊周边地区由于气候及地理位置的独特性，蕴藏丰富的嗜盐古菌资源。本实验所设计的分离方法对嗜盐古菌的分离是极其有效的，为进一步研究新疆罗布泊及周边地区嗜盐古菌资源提供了技术基础。盐度耐受实验结果验证在低盐环境中分离嗜盐古菌新物种的可行性。同时，嗜盐古菌的酶活比率较高且活性较强为进一步开发利用嗜盐古菌资源提供了理论依据。

Abstract:

Abstract: ［Objective］In order to explore the diversity of cultured halophilic archaeon from hypersaline environments in Lop Nur region and their potential application． Methods］ Total 13 soil samples were collected from Lop Nur regions．Halophilic archaea strains were isolated and identified by 16S rRNA gene sequence analysis．In addition，17 strains were selected based on different branches in pylogenetic tree，and their salt concentration tolerance and amylase，protease，esterase activities were further detected by conventional methods．［Results］The 16S rRNA gene sequences of 56 selected strains were determined，and the phylogenetic analysis was carried out．These strains were classified into 10 known genera and 5 new potential genera，and the Shannon index was 1.820．The range of salt concentration tolerance of most strains was 10%－35% (optimum at 20%－25%)．Amylase positive rate was 70.6%，protease positive rate was 35.3% and esterase positive rate was 82.4%．［Conclusion］Diverse halophilic archaeon were discovered in Lop Nur regions．The isolation methods that we used were successful for isolating halophilic archaeon from these areas，which provided the technical basis to future explore the resources of halophilic archaeon in Lop Nur regions．