Kuang Bo, Xiao Rong, Hu Yanping, Wang Yaping, Zhang Ling, Wei Zhuoqun, Bai Junhong, Zhang Kegang, Acuña Jacquelinne J, Jorquera Milko A, Pan Wenbin
College of Environment and Safety Engineering, Fuzhou University, Fuzhou, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
Front Microbiol. 2023 Jan 11;13:1112669. doi: 10.3389/fmicb.2022.1112669. eCollection 2022.
As the largest shallow freshwater lake in the North China Plain, Baiyangdian lake is essential for maintaining ecosystem functioning in this highly populated region. Sediments are considered to record the impacts of human activities.
The abundance, diversity and metabolic pathways of microbial communities in sediments were studied by metagenomic approach to reveal patterns and mechanism of C, N, P and S cycling under the threat of lake eutrophication.
Many genera, with plural genes encoding key enzymes involved in genes, belonging to Proteobacteria and Actinobacteria which were the most main phylum in bacterial community of Baiyangdian sediment were involved in C, N, S, P cycling processes, such as (Actinobacteria), , , and (Proteobacteria).For instance, the abundance of were positively correlated to TN, EC, SOC and N/P ratio in pathways of phytase, regulation of phosphate starvation, dissimilatory sulfate reduction and oxidation, assimilatory sulfate reduction, assimilatory nitrate reduction and reductive tricarboxylic acid (rTCA) cycle. Many key genes in C, N, P, S cycling were closely related to the reductive citrate cycle. A complete while weaker sulfur cycle between SO and HS might occur in Baiyangdian lake sediments compared to C fixation and N cycling. In addition, dissimilatory nitrate reduction to ammonia was determined to co-occur with denitrification. Methanogenesis was the main pathway of methane metabolism and the reductive citrate cycle was accounted for the highest proportion of C fixation processes. The abundance of pathways of assimilatory nitrate reduction, denitrification and dissimilatory nitrate reduction of nitrogen cycling in sediments with higher TN content was higher than those with lower TN content. Besides, with plural genes encoding key enzymes involved in and gene were involved in these pathways.
involved in the processes of assimilatory nitrate reduction, denitrification and dissimilatory nitrate reduction of nitrogen cycling may have important effects on nitrogen transformation.
作为华北平原最大的浅水淡水湖，白洋淀对于维持这个人口密集地区的生态系统功能至关重要。沉积物被认为记录了人类活动的影响。
采用宏基因组学方法研究沉积物中微生物群落的丰度、多样性和代谢途径，以揭示在湖泊富营养化威胁下碳、氮、磷和硫循环的模式及机制。
许多属于变形菌门和放线菌门的属参与了碳、氮、硫、磷循环过程，这些属在白洋淀沉积物细菌群落中是最主要的门类，并且具有多个编码参与相关基因的关键酶的基因，例如（放线菌门）、、、和（变形菌门）。例如，在植酸酶、磷酸盐饥饿调节、异化硫酸盐还原和氧化、同化硫酸盐还原、同化硝酸盐还原以及还原性三羧酸（rTCA）循环途径中，的丰度与总氮、电导率、有机碳和氮磷比呈正相关。碳、氮、磷、硫循环中的许多关键基因与还原性柠檬酸循环密切相关。与碳固定和氮循环相比，白洋淀湖泊沉积物中可能存在一个完整但较弱的介于亚硫酸盐和硫化氢之间的硫循环。此外，确定异化硝酸盐还原为氨与反硝化作用同时发生。甲烷生成是甲烷代谢的主要途径，还原性柠檬酸循环在碳固定过程中占比最高。总氮含量较高的沉积物中，氮循环的同化硝酸盐还原、反硝化和异化硝酸盐还原途径的丰度高于总氮含量较低的沉积物。此外，具有多个编码参与和基因的关键酶的基因也参与了这些途径。
参与氮循环的同化硝酸盐还原、反硝化和异化硝酸盐还原过程可能对氮转化有重要影响。
