蓝藻水华消亡对湖泊表层沉积物中氨氧化细菌丰度和群落结构的影响

摘要

为探索蓝藻水华消亡对湖泊表层沉积物中氨氧化细菌（ ammonia⁃oxidizing bacteria，AOB）的影响，设计了室内沉积物－水微宇宙模拟体系，体系中分别添加野外收集蓝藻和室内培养蓝藻，运用荧光定量PCR和克隆建库等分子生物学方法分析氨氧化细菌的丰度、群落结构和多样性。结果表明：（1）添加蓝藻处理组的氨氧化细菌丰度和群落多样性高于未添加蓝藻的空白对照组；（2）属于亚硝化单胞菌属（ Nitrosomonas）的N． oligotropha类群在表层沉积物的氨氧化细菌中占有绝对优势，相对丰度达75％；（3）与空白对照组相比，添加蓝藻处理组的氨氧化细菌中新出现了N． communis和Nitrosospira类群。添加蓝藻会提高沉积物中氨氧化细菌的丰度并增加其群落多样性。%A simulation system was constructed to investigate effect of withering of Cyanobacteria bloom on abundance and community composition of ammonia⁃oxidizing bacteria ( AOB) in surface sediments. The system consisted of three treat⁃ments, [i.e. (1) CK, (2) addition of lab⁃cultured Cyanobacteria and (3) addition of wild Cyanobacteria collected from a lake] . Abundance, community composition and diversity of AOB were analyzed with the real⁃time qPCR and molecular bi⁃ological methods, like clone library, etc.. Results show that (1) Treatments 2 and 3 were much higher than Treatment 1 in abundance and community diversity of AOB;( 2) N. oligotropha group of Nitrosomonas was the dominant AOB group, ac⁃counting for approximately 75% of the total AOB community in the surface sediments;and ( 3) Compared to Treatment 1, Treatments 2 and 3 were found to have some new AOB groups, such as N. communis and Nitrosospira. The findings indi⁃cate that N. oligotropha is absolutely the dominant group in all the treatments, and withering of Cyanobacteria bloom may improve AOB in the surface lake sediments in both abundance and diversity.