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. 2019 Dec 10;695:133785. doi: 10.1016/j.scitotenv.2019.133785. Epub 2019 Aug 5.
Polybrominated diphenyl ethers (PBDEs) are typical persistent organic pollutants (POPs) in the environment. However, little is known about their effects on phosphorus mineralizing bacteria (PMB) in eutrophic lake sediments, despite the critical role of PMB in phosphorus (P) biogeochemical cycling. In this study, we carried out a 60-day microcosm experiment to understand the effects of 2 and 20 mg kg dry weight decabromodiphenyl ether (BDE-209) on the activity, abundance, diversity, and community composition of PMB in the sediment of Taihu Lake, a typical eutrophic lake in China. The results showed that BDE-209 contamination, regardless of the contamination levels, significantly increased the orthophosphate concentration in overlying water and available phosphorus concentration in sediments on day 60. Such increases may be explained by the stimulatory effects of BDE-209 on alkaline phosphatase (ALP) activity and PMB abundance. Moreover, based on Miseq sequencing of the phoD gene encoding ALP, Actinobacteria was the dominant PMB phylum in all treatments, and BDE-209 significantly increased the diversity of PMB and altered their community composition. In particular, the relative abundances of some PMB genera such as Bradyrhizobium were increased significantly after 60 days of the High treatment. A co-occurrence network analysis further revealed that the high level of BDE-209 contamination strengthened the connectivity and interspecific co-operative relationships in the PMB community. These results will help us to understand the effects of POPs on P biogeochemical cycling in eutrophic lakes and the associated microbial mechanisms.
多溴联苯醚（PBDEs）是环境中典型的持久性有机污染物（POPs）。然而，尽管磷矿化细菌（PMB）在磷（P）生物地球化学循环中起着关键作用，但人们对其在富营养化湖泊沉积物中的影响知之甚少。在这项研究中，我们进行了 60 天的微宇宙实验，以了解 2 和 20mg/kg 干重十溴联苯醚（BDE-209）对中国典型富营养化湖泊太湖沉积物中 PMB 的活性、丰度、多样性和群落组成的影响。结果表明，无论污染水平如何，BDE-209 污染都会在第 60 天显著增加上覆水中的正磷酸盐浓度和沉积物中的有效磷浓度。这种增加可能是由于 BDE-209 对碱性磷酸酶（ALP）活性和 PMB 丰度的刺激作用。此外，基于 phoD 基因（编码 ALP）的 Miseq 测序结果表明，在所有处理中，放线菌是 PMB 的主要门，BDE-209 显著增加了 PMB 的多样性并改变了它们的群落组成。特别是，在高浓度 BDE-209 处理 60 天后，一些 PMB 属（如 Bradyrhizobium）的相对丰度显著增加。共现网络分析进一步表明，高水平的 BDE-209 污染增强了 PMB 群落中的连接性和种间合作关系。这些结果将有助于我们了解 POPs 对富营养化湖泊中 P 生物地球化学循环的影响及其相关的微生物机制。
