中文摘要：

对黄土中3株优势细菌（DZ023、DZ029、DZ033）进行分子鉴定和16SrDNA同源性分析,同时在实验室条件下模拟测试了这3株富含多糖细菌的持水能力.利用上海申能博彩生物公司试剂盒（K713）进行细菌基因组DNA提取,通过16SrDNA扩增与序列测定,BLAST网上比对表明,3菌株都属于芽孢杆菌属（Bacillus）.以甘肃庆阳市黄土样品为试验材料,利用对比法研究了3个菌株在黄土中的持水作用,初步研究结果表明,3个菌株均有明显持水效果,其中DZ029菌株的持水效果最佳.对于研究干旱地区的地质微生物及其应用具有借鉴意义.

英文摘要：

Three strains of bacteria（DZ023, DZ029 and DZ033）were isolated and identified from loess soil obtained from Qingyang, Gansu province, north-west part of China. Water-retaining capability is one of the most important indexes that indicate drought resistance capacity of bacteria, so the experimental test for water retention ability in soil using these bacteria were conducted in laboratory. 16SrRNA gene is widely used to classify and identify bacteria because of its special sequence in evolution. By reagent kit K713, three strains of bacteria genome were extracted, amplified and sequenced. The results showed that three strains of bacteria all belonged to Bacillus. The three strains had significant effects on the water conservation compared with the CK, especially the strain DZ029. The mechanism for the ability of bacterial water-retention in soil was attributed to their extracellular polysaccharides which have powerful water-absorbing capacity and also water retention. These can be as a good reference for loess geo-microbe studying area and fighting with drought especially in the dry land area.