蓝藻生消对巢湖沉积物phoD碱性磷酸酶基因细菌群落结构的影响  

Effects of cyanobacterial growth and decline on the phoD-harboring bacterial community structure in sediments of Lake Chaohu

作　　者：孙婷婷 黄涛[1] 刘雨昕 孙庆业[1] Sun Tingting;Huang Tao;Liu Yuxin;Sun Qingye(Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration,School of Resources and Environment Engineering,Anhui University,Hefei 230601,P.R.China)

机构地区：[1]安徽大学资源与环境工程学院,湿地生态保护与修复安徽省重点实验室,合肥230601

出　　处：《湖泊科学》2022年第6期1854-1865,共12页Journal of Lake Sciences

基　　金：安徽省重点研究与开发计划项目(201904a07020071);安徽合肥巢湖湖滨国家湿地公园科研监测项目(2021ABBBN001772)联合资助。

摘　　要：phoD基因编码的碱性磷酸酶驱动沉积物有机磷矿化并释放生物可利用磷,促进了富营养化湖泊蓝藻的生长与暴发,但对富营养化湖泊蓝藻生消周期phoD基因细菌群落动态变化的认识依然有限.本文研究了中国典型富营养化湖泊巢湖蓝藻生消过程沉积物碱性磷酸酶活性(APA)、phoD基因细菌多样性和群落结构的动态变化及其与环境的关系.结果显示:巢湖沉积物APA活性在蓝藻生长与暴发阶段显著升高,且与水温、pH、溶解氧(DO)等环境因子显著相关.蓝藻生消各阶段沉积物phoD基因细菌群落的优势菌属均由Pseudonocardia和Friedmanniella构成;与蓝藻潜伏期和衰亡期相比,生长初期与暴发期大多数样点沉积物Pseudonocardia的丰度显著降低而Friedmanniella显著升高.携带phoD基因的菌属丰度呈显著的时空变化,其中菌属丰度的空间异质性较高.蓝藻生长初期与暴发期的phoD基因细菌群落的Ace指数与Shannon多样性指数显著大于潜伏期与衰亡期.研究表明,携带phoD基因细菌群落结构的变化主要受APA、DO、叶绿素a、水温、总磷以及无机磷的驱动;春季蓝藻的生长消耗大量上覆水溶解性无机磷,激发了沉积物APA活性并诱发Friedmanniella生长从而缓解水体磷限制.The alkaline phosphatase encoded byphoDgene drives the mineralization of organic phosphorus in sediments and thus the release of bioavailable phosphorus,and promotes the growth and blooms of cyanobacteria in eutrophic lakes.The dynamic variations of phoD-harboring bacterial community during the annual cyanobacterial growth and decline in eutrophic lakes,however,remain unclear.In this study,we analyzed the alkaline phosphatase activity(APA),phoD-harboring bacterial community diversity and structure and their associations with the physicochemical factors in a typical eutrophic lake(Lake Chaohu) in China during the entire cyanobacterial growth and decline.The results showed that the APA in sediments increased significantly during the initial growth and outbreaks of cyanobacteria.Pseudonocardia and Friedmanniella are the predominantphoD-harboring genera in sediments during the entire cyanobacterial growth and decline.In contrast to the abundance of Pseudonocardia and Friedmanniella in the incubation and decline stages of cyanobacteria,Pseudonocardia decreased significantly while Friedmanniella in creased significantly in the early growth and outbreak stages.The abundance ofphoDgene bacteria varies spatiotemporally,especially for its high spatial heterogeneity.The Ace and Shannon diversity index ofphoD-harboring bacterial community during the early and outbreak stages of cyanobacteria were much higher than those in the incubation and decline stages.The changes of phoD-harboring bacterial community were mainly driven by APA,dissolved oxygen,chlorophyll-a,water temperature,total phosphorus and inorganic phosphorus.The rapid decline of dissolved inorganic phosphorus in overlying waters due to the increasing cyanobacterial photosynthesis in the early growth of cyanobacteria induces the APA,promotes the growth of Friedmanniella and alleviates the phosphorus restriction.

关 键 词：巢湖 沉积物 有机磷矿化 环境因子 蓝藻水华 phoD 碱性磷酸酶 

分 类 号：X524[环境科学与工程—环境工程]