太湖梅梁湾不同深度沉积物中细菌群落结构组成

摘要

To investigate the vertical distribution and diversity of bacterial community composition in the sediments of Taihu Lake , sediment samples were collected from Meiliang Bay in Taihu Lake .Terminal restriction fragment length polymorphism ( T-RFLP) technology was used to analyze the bacterial community composition and diversity in sediment samples of different depths .High bacterial diversities were observed in the sediments of Taihu Lake , and the bacterial species and relative abundance were found to be consistent with those in previous reports based on the culture-dependent method .Additionally , different T-RFLP patterns were observed for samples collected at different depths .Bacterial community compositions derived from those nearby samples showed greater similarities . The dominant bacterial groups varied at different depths .Moreover, the bacterial community compositions of the top and the bottom sediments showed great differences .Dissolved oxygen decreased with the increase of the depth of sediments, which shows that the variation of dissolved oxygen was the main cause of the differences in bacterial community compositions and diversity .Bioturbation induced by the submerged macrophytes and zoobenthos may be another cause .%为研究湖泊沉积物不同深度处的细菌群落结构组成和多样性，选取太湖梅梁湾作为采样点，应用末端限制性片段长度多态性（ T-RFLP）技术比较湖泊不同深度沉积物样品中细菌群落的结构组成及其多样性。结果表明：太湖沉积物中细菌具有丰富的多样性，细菌种类和相对丰度与当前已有的可培养细菌研究结果一致。细菌群落结构随着沉积物深度的增加呈现一定的变化规律，相邻近的沉积物分层中细菌群落结构的相似度较高；随着沉积物深度的增加，沉积物中优势菌属发生了一定的变化；表层沉积物与底层沉积物的细菌群落结构相差较大。鉴于氧含量随着沉积物深度的增加而逐渐减少，可以推断氧含量的变化是造成湖泊沉积物中细菌群落结构与多样性差异的主要原因。另外，表层沉积物中的生物扰动也是可能的原因。