School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-Sen University, Guangzhou, China.
FEMS Microbiol Ecol. 2011 Dec;78(3):439-50. doi: 10.1111/j.1574-6941.2011.01178.x. Epub 2011 Aug 25.
Microorganisms are important in soil development, inputs and biogeochemical cycling of nutrients and organic matter during early stages of ecosystem development, but little is known about their diversity, distribution, and function in relation to the chemical and physical changes associated with the progress of succession. In this study, we characterized the community structure and activity of nitrogen-fixing microbes during primary succession on a copper tailings. Terminal fragment length polymorphism (T-RFLP) and clone sequencing of nifH genes indicated that different N(2) -fixing communities developed under primary succession. Phylogenetic analysis revealed a diversity of nifH sequences that were mostly novel, and many of these could be assigned to the taxonomic divisions Proteobacteria, Cyanobacteria, and Firmicutes. Members of the Cyanobacteria, mostly affiliated with Nostocales or not closely related to any known organisms, were detected exclusively in the biological soil crusts and represented a substantial fraction of the respective diazotrophic communities. Quantitative PCR (and statistical analyses) revealed that, overall, copy number of nifH sequences increased with progressing succession and correlated with changes in physiochemical properties (including elementary elements such as carbon and nitrogen) and the recorded nitrogenase activities of the tailings. Our study provides an initial insight into the biodiversity and community structure evolution of N(2) -fixing microorganisms in ecological succession of mine tailings.
微生物在土壤发育、生态系统发展早期的养分和有机物质的输入和生物地球化学循环中起着重要作用，但对于与演替进程相关的化学和物理变化有关的微生物多样性、分布和功能，我们知之甚少。在这项研究中，我们研究了在铜矿尾矿的初级演替过程中固氮微生物的群落结构和活性。末端片段长度多态性（T-RFLP）和 nifH 基因的克隆测序表明，在初级演替过程中形成了不同的固氮微生物群落。系统发育分析揭示了 nifH 序列的多样性，这些序列大多是新的，其中许多可以归为变形菌门、蓝细菌门和厚壁菌门等分类单元。蓝细菌门的成员，主要与念珠藻目或与任何已知的生物体没有密切关系，仅在生物土壤结皮中检测到，并且代表了各自的固氮群落的很大一部分。定量 PCR（和统计分析）显示，总体而言，nifH 序列的拷贝数随着演替的进行而增加，并与理化性质（包括碳和氮等基本元素）的变化以及尾矿的固氮酶活性相关。我们的研究初步揭示了矿尾生态演替过程中固氮微生物的生物多样性和群落结构演化。
