塔克拉玛干沙漠腹地胡杨林土壤细菌多样性分析

摘要

[Objective]The aim of study was to investigate bacterial diversity of Populus Euphratica forest in the hinterland of Taklimakan desert.All the isolateds were be used as inoculants for silage and biofertilizer.[Methods]Strains were isolated by culture-dependent method.Gram staining, NaCl tolerance, enzyme activity (including amylase, esterase, cellulase) were determined by strand methods.Phylogenetic trees based on 16S rRNA gene sequences were constructed by using the neighbour-joining.[Results]A total of 27 strains were obtained.Phylogenetic analysis of the bacterial 16S rRNA gene showed that all isolates fell into one of the following four bacterial lineages: Actinobacteria( 16 strains) ,Proteobacteria (4 strains) ,Firmicutes(6 strains) and Bacteroidetes( 1 strains).Gram staining indicated that 5 strains were gram-negative and the others were gram-positive.Among these, 15 strains showed amylase activity,9 strains showed esterase activity and 9 strains showed cellulase activity.All strains growth occurred at in presence of 2％ NaCl,22 strains growth occurred at in presence of 5％ NaCl and only 1 strain tolerated up to 15％ NaCl.[Conclusion]The bacterial population diversity is abundant in soil of Populus Euphratica Forest in the hinterland of Taklimakan Desert, which is worthy of futher investigation.%[目的]对塔克拉玛干沙漠腹地胡杨林土壤细菌多样性进行初步探索,为下一步从中筛选可用于生物饲料或生物肥料的微生物奠定基础.[方法]采用可培养方法,进行细菌的分离纯化.对各菌株进行革兰氏染色及淀粉酶、酯酶、纤维素酶和NaCl耐受浓度的测定,并提取各菌株基因组DNA,进行16S rRNA基因扩增、测序及系统进化树的绘制,分析其多样性.[结果]共分离得到27株菌,其中放线菌门(Actinobacteria)16株,变形菌门(Proteobacteria)4株,厚壁菌门(Firmicutes)6株,拟杆菌门(Bacteroidetes)1株.革兰氏染色结果表明,5株菌为革兰氏阴性,其余为革兰氏阳性;酶活测定结果表明,15株菌具有淀粉酶活性,9株菌具有酯酶活性,9株菌具有纤维素酶活性;NaCl耐受浓度测定结果显示,NaCl浓度为2%时所有菌株均能生长,5%时能生长的有22株,15%时能生长的有1株.[结论]塔克拉玛干沙漠腹地胡杨林土壤中存在较丰富的细菌类群,且具有一定的酶学活性和NaCl耐受性,具有进一步研究开发的价值.