一株极端耐盐菌的分离鉴定及特性

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 rDNA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、pH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%,pH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Ca²⁺和Mg²⁺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。

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

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 Ca²⁺ and Mg²⁺ 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.