安徽定远盐矿可培养嗜盐微生物多样性

Species diversity of culturable halophilic microorganisms isolated from Dingyuan salt mine, Anhui

摘要:

【背景】嗜盐微生物多生活于高盐环境，具有独特的生理代谢特征，是一类重要的极端环境微生物资源。【目的】为更好地认识我国陆相盐矿的嗜盐微生物多样性组成，更好地开发利用嗜盐微生物资源积累丰富的微生物菌种。【方法】对安徽定远盐矿盐芯样品进行嗜盐微生物的纯培养分离，并对所分离菌株进行基于16S rRNA基因的测序和序列相似性分析，并对所分离菌株进行物种多样性分析。在此基础上，对代表菌株进行菌落形态和耐盐度及酶活测定。【结果】通过纯培养共分离获得了嗜盐微生物264株，其中嗜盐古菌150株，占56.8%；嗜盐细菌114株，占43.2%。嗜盐古菌物种分别来自于Halorubrum、Halopenitus、Haloterrigena、Natrinema、Natronoarchaeum和Natronomonas等6个属；嗜盐细菌物种分别来自于Pseudomonas、Aliifodinibius、Halobacillus、Halomonas和Halospina等5个属。通过代表菌株的酶活平板检测，发现产胞外蛋白酶菌株1株，酯酶1株，淀粉酶2株；能液化明胶菌株2株。在物种多样性组成方面，发现嗜盐古菌的物种多样性指数高于嗜盐细菌。【结论】本研究对我国安徽定远陆相盐矿的可培养嗜盐微生物多样性进行探究，积累了丰富的嗜盐微生物菌株资源。

Abstract:

[Background] Halophilic microorganisms living in hypersaline environment, and conceiving unique physiological and metabolic characteristics, are one type of important microbial resources from extreme environment. [Objective] To uncover species diversity of cultivable halophilic microorganisms in athalassohaline salt mines in China, and to accumulate strains of halophilic microorganisms, this research was conducted. [Methods] Culture-dependent approach was applied to analyze the halophilic microorganisms from salt core samples of Dingyuan salt mine, Anhui province, China. Classification of the culturable halophilic microorganisms was performed based on 16S rRNA gene sequencing and sequence similarity search. On this basis, some representative strains were subjected to colony morphology, salt tolerance and enzyme activity assay. [Results] In total, 264 strains were obtained via culture-dependent approach, of which 150 strains were classified as halophilic archaea, accounting for 56.8%, and 114 strains were affiliated to halophilic bacteria, accounting for 43.2%. Results of 16S rRNA gene sequence similarity search showed that those strains belonged to six haloarchaeal genera, i.e. Halorubrum, Halopenitus, Haloterrigena, Natrinema, Natronoarchaeum and Natronomonas, and five bacterial genera, i.e. Pseudomonas, Aliifodidinibius, Halobacillus, Halomonas and Halospina. Through the enzyme activity assay, one strain producing extracellular protease, one strain conceiving esterase activity and two strains presenting amylase activity, two strains hydrolyzing the gelatin, were found among these selected species. Furthermore, species diversity index of the halophilic archaea was higher than that of halophilic bacteria. [Conclusion] This study reported the species diversity of the culturable halophilic microorganisms isolated from the Dingyuan athalassohaline salt mine (Anhui, China). This study gives us a better understanding of the microbial resources in athalassohaline salt mines, and accumulates rich microbial resources for further application.