云南洱海沉积物中硫酸盐还原菌的时空分布特征

利用PCR扩增和荧光原位杂交方法分析了云南洱海沉积物中硫酸盐还原菌(Sulfate-reducing bacteria,SRB)类群和数量的时空分布特征。结果表明,秋季沉积物中检测出四个SRB类群(脱硫肠菌属、脱硫叶菌属、脱硫球菌属-脱硫线菌属-脱硫八叠菌属和脱硫弧菌属-脱硫微菌属),而春季沉积物中只检测出三个类群(脱硫肠菌属、脱硫叶菌属和脱硫球菌属-脱硫线菌属-脱硫八叠菌属)。相比春季,秋季沉积物检测出来的SRB类群具有更大的分布范围,同时,检测出的SRB类群主要分布在沉积物上部;从数量上来看,秋季沉积物SRB数量高于春季沉积物。上述结果指示秋季沉积物环境条件更适于SRB群落。此外,相比洱海秋季,洱海春季沉积环境溶解氧含量较高,且温度较低,这可能导致脱硫弧菌属-脱硫微菌属在洱海春季沉积物中处于不可育状态,由于其活性低而无法检测。

Vertical and Temporal Distributions of Sulfate-reducing Bacteria in Sediments of Lake Erhai, Yunnan Province

Vertical and temporal distributions of sulfate-reducing bacteria (SRB) in the sediments of Lake Erhai, Yunnan Province, China were analyzed based on evaluation of the presence and quantity of six main groups of SRB in sediments. Results show that four SRB groups (Desulfotomaculum, Desulfobulbus, Desulfococcus-Desulfonema-Desulfosarcina and Desulfovibrio-Desulfomicrobium) presented in autumn, while onlythree groups (Desulfotomaculum, Desulfobulbus and Desulfococcus-Desulfonema-Desulfosarcina) were detected in spring. The distribution of each SRB group in sediments collected in autumn was wider than that collected in spring, and they were mainly found in the upper sedimentsin spring. They also showed a greater overall presence and quantity in autumn than in spring. These findings indicate that the environmental conditions of autumn are more suitable for SRBs. Furthermore, compared with that in the autumn of Lake Erhai, sediments in spring of Lake Erhai have relatively high dissolved oxygen contents and low temperature, which may result in the inactive status of Desulfovibrio-Desulfomicrobium in the sediments and undetectable Desulfovibrio-Desulfomicrobium due to its low activity.