新疆盐碱地土壤耐盐芽胞杆菌的分离和鉴定

Isolation and identification of halophilic Bacillus strains from saline-alkali soils in Xinjiang

为了开发利用新疆盐碱地的耐盐菌资源,从该盐碱地土样中分离并纯化出11株耐盐能力较高的菌株,并从形态特征和16S rDNA序列分析对这些菌株进行鉴定。结果表明,11个菌株均为产芽胞,革兰氏阳性细菌。通过对这11个菌株的16S rDNA进行测序和同源性比较,发现它们与芽胞杆菌的相似性均达到99%。因此,这些菌株被鉴定为Bacillus sp.。11株菌均不能在NaCl质量浓度大于220 g/L条件下生长,属于中度耐盐菌株。耐盐基因的PCR扩增结果表明,只有NYT21、23、25、27、29等5株菌株含有pro耐盐基因,暗示这些耐盐芽胞杆菌具有不同的耐盐机制。

In order to explore and utilize microbial resources from saline-alkali land in Xinjiang,11 strains of the bacteria from the soils of Xinjiang were isolated and cultured.The strains were identified through the morphological characteristics and the 16 S rRNA sequences.The experiment result showed that all the strains were spore-forming Gram positive,16 S rDNA of the 11 strains had more than 99%sequence similarity to those published Bacillus strains,so these strains were identified as Bacillus sp.All the strains could not grow in LB medium with NaCl concentration more than 220 g/L,and belonged to moderate halophytic bacteria.The pro osmoregulatory gene responsible for salt stress tolerance,was shown to be present in NYT21,23,25,27,29 strains via PCR amplification,suggesting that these strains have different salt tolerant mechanism.