植被恢复的岩溶湿地沉积物细菌群落结构和多样性分析

为研究岩溶地区湿地生态系统的细菌群落在植被恢复过程中的结构和多样性以及环境因子对其产生的影响，以桂林会仙岩溶湿地沉积物中提取的总DNA为模板，采用Illumina HiSeq 2500高通量测序技术，对细菌16S rDNA V4、V5区进行测序并分析，共得到有效序列711 403条，序列平均长度为372.34 bp，聚类产生5 952个OTU（Operational Taxonomic Unit）.结果表明，研究区沉积物具有较高的细菌多样性，包含70个门，150个纲，195个目，325个科，446个属.其中，变形菌门（Proteobacteria）是优势类群，占比为18.33%~44.16%，并以β-变形菌纲（Betaproteobacteria）、γ-变形菌纲（Gammaproteobacteria）及δ-变形菌纲（Deltaproteobacteria）为主要组成部分，这些类群中包含了硫杆菌属（Thiobacillus）和脱硫酸盐橡菌属（Desulfatiglans）等参与硫元素循环的菌群，推测对湿地沉积物中的硫循环有着重要作用；同时，属水平上存在大量（37.85%~84.67%）未分类（Unclassified）细菌类群.在会仙岩溶湿地水质及沉积物化学指标中，与细菌群落相关性较大的是ρ（NO₃--N）、ρ（NO₂--N）、ρ（TP）和ρ（TN）等水质指标.研究显示，桂林会仙岩溶湿地细菌具有很高的多样性，沉积物中蕴藏了许多潜在新物种；并且，水质指标对沉积物细菌群落结构及多样性的影响较大，说明人为因素对于会仙岩溶湿地微生物群落结构的影响较为显著. 

Bacterial Community Structure and Diversity of Sediments in a Karst Vegetation Restoration Wetland

To investigate structure and diversity of bacterial community and the influence of environmental factors on bacterial communities in the karst vegetation wetland ecosystems, based on the total DNA extracted from the sediments of Huixian karst wetland in Guilin, the bacteria were sequenced and analyzed by the Illumina HiSeq 2500 high-throughput sequencing analysis of V4-V5 16S rDNA gene region. Overall, 711,403 effective sequences with an average length of 372.34 bp were obtained from sediment samples and 5,952 OTUs produced by Clustering. The results show that bacterial diversity was very high in these sediment samples which contain 70 phyla, 150 classes, 195 orders, 325 families and 446 genera. Proteobacteria was the dominant phylum, accounting for 18.33% to 44.16%. Among them, Betaproteobacteria, Gammaproteobacteria and Deltaproteobacteria were the main components. These groups included bacteria genus such as Thiobacillus and Desulfatiglans that are involved in the sulfur cycle, which is speculated to play an important role in the material transformation in wetland sediments. Meanwhile, a large number of unclassified bacterial groups (37.85%-84.67%) existed in samples at the genus level. Redundancy analysis of bacterial phyla and chemical parameters of water and sediments showed that NO₃^--N, NO₂^--N, TP and TN in water had more relevance to the bacterial community structure. The study shows that the bacteria in Huixian karst wetland have high diversity, and there are many potential new species in the sediments. Moreover, the water quality has a great influence on the structure and diversity of sediment bacterial community, which indicates that human factors have a significant impact on the structure of the microbial community in Huixian karst wetland.