School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
Environ Sci Pollut Res Int. 2018 Aug;25(22):21801-21810. doi: 10.1007/s11356-018-2310-x. Epub 2018 May 23.
The retention of aquatic plant debris in freshwater systems favors a reduction in soluble reactive phosphorus (P) in overlying water through microbe-mediated mechanisms in sediment. For a more complete view of the changes in sediment microbial structure and functioning when receiving plant debris, the enzyme activities and microbial community structure in sediments incubated with or without plant debris were investigated. Significantly higher fluorescein diacetate (FDA) hydrolysis, alkaline phosphatase, polyphenol oxidase, cellulase, β-glucosidase, and dehydrogenase activities were observed with plant debris treatment. High-throughput pyrosequencing showed that the number of total operational taxonomic units (OTUs) of bacteria estimated by using the Chao1 analysis was 2064 (in the control) and 1821 (with the plant debris treatment). The Shannon index, functional organization, and Venn diagrams revealed that the enriched OTUs in plant debris-treated community were less diversified than those in the control sample. The prominent bacterial phyla Firmicutes and Bacteroidetes were more diverse after plant debris addition. At the class level, the relative abundance of Alphaproteobacteria increased by 114% when plant debris was added, whereas the relative abundances of Beta-, Delta-, and Gammaproteobacteria decreased by 42, 78, and 86%, respectively. Azospirillum and Dechloromonas, the dominant phylogenetic groups at the genus level, increased with plant debris addition. Our study showed the importance of the above microbial genera in plant debris-mediated P retention in sediment.
在淡水系统中保留水生植物碎屑通过微生物介导的机制有利于减少上覆水中的可溶解性反应磷（P）。为了更全面地了解沉积物中接收植物碎屑时微生物结构和功能的变化，研究了用或不用植物碎屑孵育的沉积物中的酶活性和微生物群落结构。在有植物碎屑处理的情况下，荧光素二乙酸酯（FDA）水解、碱性磷酸酶、多酚氧化酶、纤维素酶、β-葡萄糖苷酶和脱氢酶活性显著更高。高通量焦磷酸测序显示，通过 Chao1 分析估计的细菌总操作分类单元（OTU）数量在对照组中为 2064 个，在有植物碎屑处理组中为 1821 个。Shannon 指数、功能组织和 Venn 图表明，与对照样品相比，植物碎屑处理组中富集的 OTU 多样性较低。添加植物碎屑后，厚壁菌门和拟杆菌门等优势细菌门的多样性增加。在纲水平上，添加植物碎屑后α变形菌的相对丰度增加了 114%，而β-、δ-和γ-变形菌的相对丰度分别下降了 42%、78%和 86%。在属水平上，优势的系统发育组 Azospirillum 和 Dechloromonas 随着植物碎屑的添加而增加。我们的研究表明了这些微生物属在植物碎屑介导的沉积物中 P 保留中的重要性。
