Singlet oxygen, a neglected but important environmental factor: short-term and long-term effects on bacterioplankton composition in a humic lake
Singlet oxygen, a neglected but important environmental factor: short-term and long-term effects on bacterioplankton composition in a humic lake
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DOI：
10.1111/j.1462-2920.2010.02285.x
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发表时间：
2010-12-01
影响因子：
5.1
通讯作者：
Glaeser, Jens
中科院分区：
文献类型：
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作者：
Glaeser, Stefanie P.;Grossart, Hans-Peter;Glaeser, Jens
溶解性有机物（DOM）的光解对浮游细菌的动力学有不同的影响，即对细菌活性的刺激和抑制。特别是，短寿命的活性氧（ROS），如单线态氧（1 O（2）），在改变微生物活性和物种组成的作用几乎没有研究。因此，我们已经人为地增加了自然率1 O（2）的形成在短期（类似于4小时）的原位和长期（72小时）的实验室培养的地表水样品从腐殖酸丰富的湖泊。变性梯度凝胶电泳（DGGE）图谱显示，1 O（2）暴露后，大量浮游细菌的发生显着变化。DGGE图谱聚类分析表明，1 O（2）暴露量的适度增加导致不同年份的相似变化，表明适应1 O（2）暴露的细菌群落的建立。在这些条件下，浮游细菌的优势类群属于β-Ⅱ类的β-变形菌（如多核细菌necessarius）和与湖沼生境相关的β-Ⅰ类（R-BT亚类），以及隶属于嗜酸新鞘氨醇菌的α-变形菌。相比之下，淡水acI-B簇的放线菌甚至对中等1 O（2）暴露敏感。我们的结论是，1 O（2）暴露，由于DOM的光解是一个重要的自然选择性因素，影响细菌物种动态的水生生态系统在许多方面。
P>Photolysis of dissolved organic matter (DOM) leads to contrasting effects on bacterioplankton dynamics, i.e. stimulation and inhibition of bacterial activity. In particular, the role of short-lived reactive oxygen species (ROS), e.g. singlet oxygen (1O(2)), in altering microbial activity and species composition has scarcely been investigated. Therefore, we have artificially increased the natural rate of 1O(2) formation in short-term (similar to 4 h) in situ and long-term (72 h) laboratory incubations of surface water samples from a humic acid-rich lake. Denaturing gradient gel electrophoresis (DGGE) patterns revealed significant changes in occurrence of abundant bacterioplankton phylotypes upon 1O(2) exposure. Cluster analysis of DGGE patterns showed that a moderate increase in 1O(2) exposure leads to similar changes in different years indicating the establishment of bacterial communities adapted to 1O(2) exposure. Bacterioplankton phylotypes favoured under these conditions belonged to Betaproteobacteria of the beta II cluster (e.g. Polynucleobacter necessarius) and the beta I cluster related to Limnohabitans (R-BT subcluster) as well as Alphaproteobacteria affiliated to Novosphingobium acidiphilum. In contrast, Actinobacteria of the freshwater acI-B cluster were sensitive even against moderate 1O(2) exposure. We conclude that 1O(2) exposure due to DOM photolysis represents an important natural selective factor affecting bacterial species dynamics in aquatic ecosystems in many ways.