Wang Kai, Zhang Demin, Xiong Jinbo, Chen Xinxin, Zheng Jialai, Hu Changju, Yang Yina, Zhu Jianlin
School of Marine Sciences, Ningbo University, Ningbo, China 2011 Center of Modern Marine Aquaculture of East China Sea, Ningbo, China.
School of Marine Sciences, Ningbo University, Ningbo, China 2011 Center of Modern Marine Aquaculture of East China Sea, Ningbo, China
Appl Environ Microbiol. 2015 Jan;81(1):231-40. doi: 10.1128/AEM.02562-14. Epub 2014 Oct 17.
Multiple anthropogenic disturbances to bacterial diversity have been investigated in coastal ecosystems, in which temporal variability in the bacterioplankton community has been considered a ubiquitous process. However, far less is known about the temporal dynamics of a bacterioplankton community responding to pollution disturbances such as toxic metals. We used coastal water microcosms perturbed with 0, 10, 100, and 1,000 μg liter(-1) of cadmium (Cd) for 2 weeks to investigate temporal variability, Cd-induced patterns, and their interaction in the coastal bacterioplankton community and to reveal whether the bacterial community structure would reflect the Cd gradient in a temporally varying system. Our results showed that the bacterioplankton community structure shifted along the Cd gradient consistently after a 4-day incubation, although it exhibited some resistance to Cd at low concentration (10 μg liter(-1)). A process akin to an arms race between temporal variability and Cd exposure was observed, and the temporal variability overwhelmed Cd-induced patterns in the bacterial community. The temporal succession of the bacterial community was correlated with pH, dissolved oxygen, NO3 (-)-N, NO2 (-)-N, PO4 (3-)-P, dissolved organic carbon, and chlorophyll a, and each of these parameters contributed more to community variance than Cd did. However, elevated Cd levels did decrease the temporal turnover rate of community. Furthermore, key taxa, affiliated to the families Flavobacteriaceae, Rhodobacteraceae, Erythrobacteraceae, Piscirickettsiaceae, and Alteromonadaceae, showed a high frequency of being associated with Cd levels during 2 weeks. This study provides direct evidence that specific Cd-induced patterns in bacterioplankton communities exist in highly varying manipulated coastal systems. Future investigations on an ecosystem scale across longer temporal scales are needed to validate the observed pattern.
在沿海生态系统中，人们已经对多种人为干扰对细菌多样性的影响进行了研究，浮游细菌群落的时间变异性被视为一个普遍存在的过程。然而，对于浮游细菌群落响应诸如有毒金属等污染干扰的时间动态，我们所知甚少。我们使用了用0、10、100和1000微克/升镉（Cd）扰动2周的沿海水微宇宙，来研究沿海浮游细菌群落的时间变异性、Cd诱导模式及其相互作用，并揭示细菌群落结构是否会在一个随时间变化的系统中反映Cd梯度。我们的结果表明，浮游细菌群落结构在培养4天后沿Cd梯度持续变化，尽管它在低浓度（10微克/升）时对Cd表现出一定抗性。观察到一个类似于时间变异性和Cd暴露之间军备竞赛的过程，并且时间变异性在细菌群落中压倒了Cd诱导模式。细菌群落的时间演替与pH、溶解氧、NO3 (-)-N、NO2 (-)-N、PO4 (3-)-P、溶解有机碳和叶绿素a相关，并且这些参数中的每一个对群落变异的贡献都比Cd更大。然而，升高的Cd水平确实降低了群落的时间周转率。此外，隶属于黄杆菌科、红杆菌科、赤杆菌科、鱼立克次氏体科和交替单胞菌科的关键分类群在2周内与Cd水平相关的频率很高。这项研究提供了直接证据，表明在高度变化的受控沿海系统中存在浮游细菌群落特定的Cd诱导模式。未来需要在更长时间尺度上进行生态系统规模的调查，以验证观察到的模式。
