一株极端耐盐菌的分离鉴定及特性

Isolation,identification and characteristics of an extreme salt-tolerant strain

从危险废物填埋场新鲜渗滤液中分离纯化得到1株极端耐盐菌,编号为NY-1。通过形态学观察、革兰氏染色和16S r DNA基因序列分析,鉴定该菌株为无色杆菌属(Achromobacter sp.)。考察不同盐度、培养基和营养液、p H对NY-1生长的影响,并对不同盐度条件下NY-1胞内阳离子变化进行耐盐分析。结果表明,NY-1在盐质量分数为10%~20%,p H为7.0、温度30℃的LB培养基中生长最好;NY-1通过吸收K^+和Na^+来维持细胞内的渗透平衡,同时需释放Ca^(2+)和Mg^(2+)来维持细胞内的电中性环境,当盐质量分数高于20%时,持续向外环境释放Na^+来抵抗外界的高盐度对NY-1细胞的干扰。NY-1可为高盐度废水生物处理和土壤修复提供菌株资源。

An extremely salt-tolerant strain named NY-1 was isolated from the fresh filtrate of Wushan hazardous waste landfill.Based on morphological,gram staining and 16S rDNA sequence analysis,the strain was identified as Achromobacter sp..The strain NY-1 can survive under salinity 0-30%.Effects of different medium,salinity gradient,pH and temperature on the growth of strain NY-1 were studied,the results showed that the optimum conditions were salinity 10%-20%,pH 7.0,30℃in the LB medium.The salt-tolerant mechanism of strain NY-1 was analyzed by the changing of intracellular cation in different salinity.Under low salinity,the strain NY-1 absorbed K+and Na+to maintain the osmotic balance inside the cell,and released Ca 2+and Mg 2+to maintain neutral environment inside the cell.When the salinity was above 20%,the strain NY-1 resisted the interference of high salinity by sustaining to release Na+to the extra-cellular environment.In conclusion,the strain NY-1 shows the potential of application in biological treatment of high salinity wastewater and soil bioremediation.