Key Laboratory of Integrated Regulation and Resource Department on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China.
Key Laboratory of Integrated Regulation and Resource Department on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing 210098, PR China.
Sci Total Environ. 2022 Oct 15;843:157073. doi: 10.1016/j.scitotenv.2022.157073. Epub 2022 Jun 30.
Although sulfate (SO) reduction by sulfate-reducing bacteria (SRB) is an important sulfur cycling processes, little is known about how the persistent organic pollutants affect the SO reduction process in the eutrophic lake sediments. Here, we carried out a 120-day microcosm experiment to explore the effects of decabromodiphenyl ether (BDE-209) on SO reduction mediated by SRB in sediment collected from Taihu Lake, a typical eutrophic lake in China. The results showed that BDE-209 contamination significantly enhanced the activity of dissimilatory sulfite reductase (DSR) (r = 0.83), which led to an increased concentration of sulfide produced by SO reduction. This stimulatory effect of BDE-209 on DSR activity was closely related to variations in the dsrA- and dsrB-type SRB communities. The abundances and diversities of the dsrA- and dsrB-containing SRB increased and their community composition varied in response to BDE-209 contamination. The gene copies (r = 0.72), Chao 1 (r = 0.50), Shannon (r = 0.55), and Simpson (r = 0.70) indices of dsrB-containing SRB was positively correlated with BDE-209 contamination. Co-occurrence network analysis revealed that network complexity, connectivity, and the interspecific cooperative relationship in SRB were strengthened by BDE-209 contamination. The keystone species identified in the SRB community mainly belonged to the genera Candidatus Sulfopaludibacter for the dsrA-containing SRB and Desulfatiglans for the dsrB-containing SRB, and their relative abundances were positively correlated with DSR activity in the sediment. The relative abundance of the keystone species and SRB diversity were important microbial factors directly contributing to the variations in DSR activity based on structural equation modeling analysis. Notably, the results of abundance, community structure, and interspecific relationships showed that the dsrB-containing SRB may be more sensitive to the BDE-209 contamination than the dsrA-containing SRB. These results will help us understand the effects of BDE-209 on microbial sulfate reduction in eutrophic lakes.
虽然硫酸盐还原菌 (SRB) 介导的硫酸盐还原作用是一种重要的硫循环过程，但对于持久性有机污染物如何影响富营养化湖泊沉积物中的硫酸盐还原过程，人们知之甚少。在这里，我们进行了一项为期 120 天的微宇宙实验，以探讨十溴二苯醚 (BDE-209) 对中国典型富营养化湖泊太湖沉积物中由 SRB 介导的硫酸盐还原的影响。结果表明，BDE-209 污染显著增强了异化亚硫酸盐还原酶 (DSR) 的活性 (r = 0.83)，导致硫酸盐还原产生的硫化物浓度增加。BDE-209 对 DSR 活性的这种刺激作用与 dsrA-和 dsrB 型 SRB 群落的变化密切相关。dsrA-和 dsrB 型 SRB 的丰度和多样性增加，群落组成也因 BDE-209 污染而发生变化。dsrB 型 SRB 的基因拷贝数 (r = 0.72)、Chao1 (r = 0.50)、Shannon (r = 0.55) 和 Simpson (r = 0.70) 指数与 BDE-209 污染呈正相关。共现网络分析表明，BDE-209 污染增强了 SRB 网络的复杂性、连通性和种间协同关系。SRB 群落中的关键种主要属于 Candidatus Sulfopaludibacter 属（dsrA 型 SRB）和 Desulfatiglans 属（dsrB 型 SRB），其相对丰度与沉积物中 DSR 活性呈正相关。基于结构方程模型分析，关键种的相对丰度和 SRB 多样性是直接导致 DSR 活性变化的重要微生物因素。值得注意的是，丰度、群落结构和种间关系的结果表明，dsrB 型 SRB 可能比 dsrA 型 SRB 对 BDE-209 污染更为敏感。这些结果将有助于我们了解 BDE-209 对富营养化湖泊中微生物硫酸盐还原的影响。
