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. 2018 Mar;616-617:1045-1055. doi: 10.1016/j.scitotenv.2017.10.214.
While nitrogen (N) fixation and ammonia oxidation by microorganisms are two important N cycling processes, little is known about how the microbes that drive these two processes respond when sediments are contaminated with persistent organic pollutants. In this study, we carried out a laboratory microcosm experiment to examine the effects of decabromodiphenyl ether (BDE-209), either on its own or combined with a common mangrove species, Avicennia marina, on the abundance, diversity, and community composition of N-fixing bacteria (NFB) and ammonia-oxidizing archaea (AOA) and bacteria (AOB) in mangrove sediments. The sediments were very N-limited after one year. The rates of N fixation and NFB abundance were significantly higher in the sediments that contaminated by BDE-209, especially in the planted sediment, indicating that both BDE-209 and planting stimulated N fixation in N-limited mangrove sediments. In contrast, the potential nitrification rate and abundance of AOA and AOB decreased significantly under BDE-209 and planting, and the inhibitory effects were stronger in the sediment with both planting and BDE-209 than in the sediments with either BDE-209 or planting. The results from pyrosequencing showed that the richness and diversity of NFB increased, while those of AOA and AOB decreased, in the sediments treated with BDE-209 only and with BDE-209 combined with planting. The community compositions of NFB, AOA, and AOB in the sediments shifted significantly because of BDE-209, either alone or particularly when combined with planting, as shown by the increases in some NFB from the Proteobacteria phylum and decreases in AOA in the Nitrosopumilus genus and AOB in the Nitrosospira genus, respectively.
虽然微生物的氮固定和氨氧化是两个重要的氮循环过程，但对于驱动这两个过程的微生物在沉积物受到持久性有机污染物污染时如何响应，我们知之甚少。在这项研究中，我们进行了一项实验室微宇宙实验，以研究十溴二苯醚（BDE-209）单独或与常见红树林物种桐花树（Avicennia marina）一起对红树林沉积物中固氮菌（NFB）和氨氧化古菌（AOA）和细菌（AOB）的丰度、多样性和群落组成的影响。一年后，沉积物中的氮非常有限。在受 BDE-209 污染的沉积物中，氮固定和 NFB 丰度的速率显著更高，特别是在种植的沉积物中，这表明 BDE-209 和种植都刺激了氮有限的红树林沉积物中的氮固定。相比之下，在 BDE-209 和种植的情况下，潜在硝化速率和 AOA 和 AOB 的丰度显著降低，而在同时种植和 BDE-209 的沉积物中，抑制作用比在仅受 BDE-209 或种植的沉积物中更强。焦磷酸测序的结果表明，在仅受 BDE-209 处理和受 BDE-209 与种植结合处理的沉积物中，NFB 的丰富度和多样性增加，而 AOA 和 AOB 的丰富度和多样性减少。由于 BDE-209 单独或特别是与种植结合，NFB、AOA 和 AOB 的群落组成发生了显著变化，分别表现为一些来自变形菌门的 NFB 的增加和硝化螺旋菌属中的 AOA 和亚硝化单胞菌属中的 AOB 的减少。
