盐碱土中可培养中度嗜盐菌的研究

为了调查大庆盐碱地的中度嗜盐菌资源,采集重度盐碱化的土壤样本进行嗜盐微生物的分离纯化,获得45株中度嗜盐细菌。形态学特征显示,40%菌落呈黄色,其余为乳白色;细胞为直线或弯曲的杆状,G+和G-细菌比例为19:26。进一步的生理生化特征分析筛选出8株进行16S rDNA基因序列的测定及系统发育分析。结果表明,它们分别属于Bacillus(3株),Halomonas(2株)和Alkalibacillus(3株)属的菌株。菌株15-2应为现有种Bacillus agaradhaerens,X10-1(或X10-7)可能为Bacillus属潜在的新种,15-7(或X10-2)可能为Halomonas潜在的新种,有待于进一步的验证。研究虽然仅获得了有限的中度嗜盐菌资源,但却丰富了我们对大庆盐碱土中可培养中度嗜盐菌多样性的认识,为今后合理开发和利用大庆地区的嗜盐微生物资源提供了素材和参考。

Culturable moderately halophilic bacteria isolated from saline-alkali soil

To investigate the resources of moderately halophilic bacteria from the saline-alkaline soils of Daqing city, 45 halophilic strains were isolated and purified from the heavy saline soil. The morphological characteristics showed that 40%of the colonies were yellow and the others were creamy, cells were line or curved rod-shaped. The ratio of gram-positive and gram-negative was 19:26. Eight repetitive strains were screened out using further physiological and biochemical analyses and their phylogenetic positions were determined by 16S rDNA gene sequence analysis. Sequence similarity analysis of the 16S rDNA gene showed that three strains were closely related to the genus Bacillus, two strains were closely related to the genus Halomonas and three strains were closely related to the genus Alkalibacillus. Strain 15-2 may be one of the existing species Bacillus agaradhaerens, strain X10-1 (or X10-7) may be a potential new species of the genus Bacillus, strain 15-7 (or X10-2) may be a potential new species of the genus Halomonas, which needs further verification. Although limited resources of moderately halophlilic bacteria were isolated in this study, a deeperunderstanding of the diversity of moderately halophilic bacteria from saline soil from Daqing may be obtained. We provided a source of reference for future rational exploitation and utilization of halophilic microorganism resources in Daqing.