新疆罗布泊嗜碱细菌的分离及其生理学特性的初步研究

从新疆罗布泊“大耳朵”地区的湖盆沉积物中分离得到151个细菌菌株。研究比较了不同培养基的分离效果,测定了嗜碱细菌生长的pH值范围,对不同碱性物质KOH、K2CO3、NaOH、Na2CO3的选择性和对NaCl、KCl的耐受性。结果表明,添加了罗布泊盐壳浸提物的培养基更有利于嗜碱细菌的富集培养和分离。分离菌株中专性嗜碱菌、兼性嗜碱菌和耐碱菌的比例分别为29.8%,39.7%和30.5%。54.3%的嗜碱菌菌株对4种碱性物质具有广泛的适应性,13.2%菌株对Na^＋有一定的依赖性,对含K^＋碱性物质敏感,只有1.9%的菌株对CO32-碱性物质敏感。77.1%嗜碱细菌可以耐受7%-15%的NaCl和10%-20%的KCl,具有较强的耐盐特性,其中是否存在嗜盐碱双极端因子的古菌,尚有待进一步研究确定。

Preliminary Studies on Isolation of Alkaliphilic Bacteria from Lop Nor Region and Their Physiological Characteristics

One hundred and fifty one bacteria stains were isolated from the sediment samples from ＂great ear＂ of Lop Nor region,Xinjiang. Effects of different medias on alkaliphile isolation,growth pH range, selectivity to different alkaline materials KOH, K2 CO3, NaOH and Na2 CO, NaCl, KCl tolerance concentration of the isolates were studied. The result indicated that the media,to which was added the extract of the salt crust,was proved to be more advantageous to the enrichment culture and isolation of the alkaliphilic bacteria. According to growth pH range,the isolates were classified into obligate alkalophile,facultative alkaliphile and alkalotolerant, the proportion were 29.8%, 39.7% and 30. 5%, respectively. The alkaliphile of 54.3 % were extensive adaptability to the alkaline materials, 13.2% of them were obligately dependent on Na^＋ ,and sensitive to K^＋ alkaline materials. Only 1.9 % of the alkaliphile were CO3^2- sensitive. It was also showed that 77.1% of the alkaliphilc bacteria had tolerance to 7%-15% NaCl and 10%-20% KCl,and further study should be conducted on confirm the possibility for the existent of haloalkaliohilic archaea in the strains.