不同温度影响下除铀厌氧微生物群落结构特征解析

为了考察温度对除铀微生物群落结构的影响，通过高通量测序技术分析15℃、25℃和35℃三个温度条件下除铀厌氧微生物的群落组成及丰度.经过48h对7.2mg/L铀的去除试验，温度为35℃情况下厌氧微生物除铀率（99.1%±0.3%）显著高于15℃和25℃的情况.不同温度除铀厌氧菌群中共有菌属居多（43种）.在细菌门水平上，15℃和25℃条件下的厚壁门细菌（Firmicutes）丰度最高，比例分别为61.7%与63.3%，而35℃下变形菌门（Proteobacteria）丰度最高，比例为68.0%.在细菌属水平上，15℃和25℃样品中的第一大类菌属为Trichococcus；但在35℃样品中，Klebsiella丰度最高，比例达到52%，其他优势微生物有Proteiniclasticum（11%）、Clostridium（8%）、Acinetobacter（6%）、Enterobacteriaceae（5%）、Citrobacter（4）、Sedimentibacter（4%）、Desulfovibrio（3%）等.不同温度影响下，除铀厌氧菌群物种丰度差异极其显著.冗余分析发现温度作为环境因子与35℃样本群落结构为正相关关系.而温度对Klebsiella及Trichococcus影响程度最大，但分别为促进丰度增加（正相关）及显著降低丰度（负相关）.

Characterization of microbial community succession for uranium removal under different temperature

In order to investigate the effect of the temperature on microbial community of uranium removal consortium, the microbial composition and abundance of the anaerobic bacteria in the samples under 15, 25 and 35℃ were detected using high-throughput sequencing technique. After exposed in initial 7.2mg/L uranium for 48h, a removal efficiency of 99.1%±0.3% was obtained for the sample under 35℃, which is much higher than that in 15 and 25℃. A majority of common bacterial genera were found in three samples under different temperatures (43 genera). At the phylum level, Firmicutes predominated in the 15℃ and 25℃ samples, with the proportions of 61.7% and 63.3%, respectively. While Proteobacteria was the dominant phylum in the 35℃ sample whose proportion was as high as 68.0%. At the genus level, the first major genus in samples of both 15℃ and 25℃ was Trichococcus. However, for 35℃ sample, it contained Klebsiella with the highest relative abundance as 52%, and other dominant microorganisms including Proteiniclasticum (11%), Clostridium (8%), Acinetobacter (6%), Enterobacteriaceae (5%), Citrobacter (4%), Sedimentibacter (4%), Desulfovibrio (3%). Therefore, the composition and abundance of anaerobic consortium for uranium removal significantly varied with temperature. A positive correlation between temperature and the microbial community of 35℃ sample was observed by RDA analysis. The increase of temperature significantly promoted the abundance of Klebsiella (positive correlation), but dramatically reduced that of Trichococcus (negative correlation).