浑善达克沙地生物土壤结皮细菌群落特征

CHARACTERIZATION OF BACTERIAL COMMUNITY STRUCTURE IN BIOLOGICAL SOIL CRUSTS FORM DESERT HUNSHANDAKE

微生物可凝聚土壤颗粒形成生物土壤结皮(BSCs),其在荒漠化土壤植被恢复具有举足轻重的作用。通过构建环境样品16S rDNA文库,本文分析了浑善达克沙地生物土壤结皮(BSCs)细菌群落组成特征及其与结皮形成演替的关系。结果表明:浑善达克沙地BSCs中细菌主要类群为α-和γ-变形杆菌。其中,优势菌是γ-变形杆菌门中的假单胞菌科(Pseudomonadaceae),不动杆菌属(Acinetobacter)和α-变形菌门中的鞘氨醇单胞菌属(Sphingomonas),分别占到总细菌数14.5%,18.2%和12.7%。而Cyanobacteria类群很少,仅占全部克隆的1.8%,这使其细菌群落组成特征明显不同于成熟BSCs。因此,在BSCs早期发育或重建早期时期,起先锋拓殖作用的可能是Cyanobacteria之外的其他异养和自养细菌。

Microorganisms play a significant role in vegetation rehabilitation because they can cohere soil particles to form biological soil crusts（BSCs）.This study characterized bacteria community of the BSCs and discussed the relationship between bacteria and BSCs succession in Desert Hunsandake,by constructing and analyzing 16S rDNA literary of the environmental sample.The results showed that the bacterial majority were affiliated to α-,γ-proteobacteria.The dominant bacteria were Pseudomonadaceae and Acinetobacter of γ-proteobacteria（they accounted for 14.5% and 18.2%,of total bacteria,respectively）,as well as Sphingomonas（it accounted for 12.7%） of α-proteobacteria.However,the dominant bacteria,namely Cyanobacteria,in well developed BSCs,was only 1.8% of total clones in this study,which was the distinguished profile of the BSCs and this suggested that it was heterotrophic and other autotrophic bacteria rather than Cyanobacteria,in pioneering colonization during early development and reconstruction of BSCs.