烟台海域一株中度嗜盐芽孢杆菌YTM-5的鉴定及其耐盐机制研究

从山东烟台近海盐场泥样中分离得到菌株YTM-5,该菌株能在1%～15%NaCl的培养基中生长,最适宜生长条件为：3%NaCl,温度为37℃,pH值为8。经过形态学观察、生理生化特性分析及16S rDNA序列测定,鉴定该菌株为芽孢杆菌Bacillus。高压液相色谱分析表明YTM-5菌体内含有相容性溶质四氢嘧啶,其含量随培养基内NaCl含量的增加而增加,当NaCl含量达到7%以上时,一直维持较高的水平,以稳定此逆境下的渗透平衡。该菌株的发现为开发烟台海域海洋微生物资源及相关抗盐基因的利用奠定了基础。

Identification of a Moderately Halophilic Bacillus Strain YTM-5 in Yantai Sea Area and the Preliminary Study of its Salt-tolerant Mechanism

The moderate halophilic bacteria have a prosperous prospect in modification of environmental pollution.A moderate halophilic bacterium YTM-5 was isolated from soil samples of salt field near Yantai maritime space.It can grow on the LB medium contained 1%～15% NaCl.The optimal growth salinity of YTM-5 is 3%,the optimum growth temperature and pH value is 37 ℃ and 8,respectively.According to the morphological,physiological and biochemical analysis and the sequence of 16S rDNA,it was identified as Bacillus.HPLC analysis showed that YTM-5 contained compatible solute of ectoine which can stabilize the osmotic pressure balance under the high salinity adversity.The concentration of ectione improved as the increase of medium salinity,and it can keep at a high level when the salinity reaches 7%.The discovery of YTM-5 will lay the groundwork for the exploitation of the microbial resources in Yantai maritime space and will also facilitate the utility of related haloduric gene.