内蒙古额吉淖尔盐碱湖一株产视紫红质的极端嗜盐古菌的分离及其bop基因核心序列及最适生长条件的分析

从内蒙古额吉淖尔湖分离得到一株产视紫红质的极端嗜盐古菌,初步鉴定为属于Natrinema属;并扩增出了其bop基因,该bop基因序列已在Genbank中注册,编号为KF863690,分析了其核心序列。结果表明bop基因开放阅读框为303 bp,编码101个氨基酸。blastp结果表明该蛋白属于Bac-rhodopsin蛋白家族,具有典型的细菌视紫红质蛋白结构域。利用BLAST进行相似性分析发现bop编码蛋白氨基酸序列与Genbank中编号AAS87571.1、WP-007110705和AFB77278.1的视紫红质蛋白相似性达到98%以上。此结果表明视紫红质蛋白在细菌及古菌中结构上具有很高的保守性,与其质子泵功能紧密相关。最后分析了该菌株的最适生长条件。该菌株在分离培养基中适宜生长的NaCl浓度范围为1.0~3.0 mol/L,适宜生长pH为6.5~8.5,适宜生长镁离子浓度为0.4~0.8 mol/L。通过分析比较得出该嗜盐古生菌株生长最适NaCl盐浓度为1.5 mol/L,最适pH值为7.5,最适镁离子浓度为0.4 mol/L。该实验结果为今后进一步研究产视紫红质的极端嗜盐古生菌株的生理生化特征及遗传学特征奠定了基础。

Isolation of a rhodopsin producing extreme halophilic archaea from Eejnoor in Inner Mongolia and analysis of its bop gene sequence and optimal growthconditions

In this study a rhodopsin producing extreme halophilic archaea was isolated from Eejnoor in Inner Mongolia . It was preliminary identified as an archaea belonging to the genus Natrinema. Its bop gene was amplified and the core sequence of the bop gene and the optimum growth conditions of the strain have been analyzed. This sequence has been registered in Genbank, NO KF863690.The results show that the bop gen has an open reading frame with a 303 bp, encoding 101 amino acids. Blastp result shows that this protein belongs to bacteriorhodopsin super family and has the typical structure domain of bacteriorhodopsin. Similarity analysis using the BLAST shows that the bop gene encoded amino acid sequence has a similarity of above 98% with the genes AAS87571.1, WP-007110705 and AFB77278.1 in Genbank encoded rhodopsin. This results indicate that rhodopsin proteins in bacteria and archaea are ihighly conserved in their structure, and this is closely related with their proton pump function. The suitable condition for the growth of the strain in the separation medium is 1.0 ~ 3.0mol/L NaCl, pH 6.5 ~8.5, magnesium ion concentration 0.4 ~ 0.8 mol / L. The optimum NaCl concentration is 1.5 mol/L, the optimum pH value is 7.5, and the optimum magnesium ion concentration is 0.4 mol/L for the growth of the strain. The experimental results laid a foundation for the further study of physiological and biochemical characteristics and genetics of the rhodopsin producing extremely halophilic archaea .