以四川自贡大公古盐井盐卤为研究对象, 分离获得112株中度嗜盐菌。经形态特征、生理生化特征和16S rRNA同源序列分析表明：112菌株分属于细菌域的Planococcus、Halomonas、Halobacillus、Oceanobacillus和Virgibacillus属, 与P. rifitiensis和H. venusta、H. trueperi、H. blutaparonensis、V. picturae在16S rRNA基因水平分别有100%和99%的高相似性。但菌株QW06、QW12、QW15和QW18分别与O. profundus、H. trueperi和H. blutaparonensis在菌落形态、革兰氏染色、产酸、明胶水解和淀粉水解等表型特征上有明显的差异。同时, 16S-23S rRNA ISR-PCR基因指纹图谱也表明QW06、QW12、QW15和QW18不同于参考菌株O. profundus KCCM 42318和H. trueperi DSM 1040T、H. blutaparonensis ATCC BAA 1217T, 说明QW06、QW12、QW15和QW18分类地位有待进一步确定。实验结果不仅揭示了大公古盐井中可培养中度嗜盐菌的多样性和系统发育关系, 而且也表明了16S rRNA高度相似菌的16S-23S rRNA ISR在进化的过程中发生了某些突变
Abstract: 112 aerobic moderate halophilic bacteria were isolated from Daong Ancient Brine Well located in Zigong city, Sichuan Province, China. And they were subjected to the analysis of phenotype, physiology, 16S rRNA sequence. Furthermore, the intra specific phylogeny of closely related strains was also screened by PCR fragment length polymorphism of 16S-23S ribosomal RNA intergenic spacer regions (ISR). The re-sult showed that the halophilic isolates found in current study were closely related to the following genera: Planococcus, Halomonas, Halobacillus, Oceanobacillus and Virgibacillus, a lineage of the domain Bacteria. 16S rRNA analysis revealed that their sequences sharing 100% and 99% similarity were obtained from the GenBank database for P. rifitiensis, H. venusta, H. trueperi, H.blutaparonensis, O. profundus and V. pciturae. However, isolates QW06、QW12、QW15 and QW18 exhibited differences from their corresponding reference strains to some degree, including colony pigmentation, gram staining, acid production and hydrolysis of gelatin, casein and starch. The ISR analysis disclosed variation of banding pattern in these isolates related to Oceanobacillus and Halobacillus which was observed with phenotypic and physiological characterizations as well. It was clear that these halophiles have adapted to the special man-made hypersaline environment by the basic physiological evolution during phylogenesis. So they could be determined according to further polyphasic taxonomy data. The current primary result also indicated the diversity of species of culture-dependent moderately halophilic bacteria colonizing in Dagong Ancient Brine Well as well as phenotypic and genotypic and phylogenetic diversity.
