Sun Tingting, Zhu Linlin, Huang Tao, Tao Pengliang, Bao Yan, Wang Bo, Sun Qingye, Chen Kaining
School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China.
School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China; Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Hefei 230601, China.
J Environ Sci (China). 2025 Aug;154:226-237. doi: 10.1016/j.jes.2024.07.028. Epub 2024 Aug 4.
Understanding the coupling relationships among lake physicochemical properties, internal nutrient recycling, and related microbes is key for the control of freshwater eutrophication. In this study, seasonal variations in microorganisms at the sediment-water interface (SWI) of the eutrophic Lake Chaohu in China were analyzed, in order to reveal changes in phosphorus (P)-cycling-related microbes in the sediments and its association with internal P release during the cyanobacterial life cycle. The identified P-cycling-related microbes include phosphorus-solubilizing bacteria (PSB) (dominant of Bacillus, Thiobacillus and Acinetobacter), sulfate-reducing bacteria (SRB) (dominant of Sva0081_ sediment_ group, norank_ c__ Thermodesulfovibrionia and Desulfatiglans) and iron-reducing bacteria (FeRB) (dominant of Geothermobacter, Anaeromyxobacter, Thermoanaerobaculum and Clostridium_sensu_stricto_1). Increased PSB and reduced proportions of iron-aluminum-bound P (Fe/Al-P) and calcium-bound P (Ca-P) from the benthic stage to initial cyanobacterial growth indicated that internal phosphorus was released through the solubilization of Fe/Al-P and Ca-P by PSB. Growth of cyanobacteria was accompanied by cyanobacteria death, deposition, and degradation during early algal blooms, which increased SRB caused by high organic matter and the net deposition of phosphorus in the western lake. Conversely, phosphorus release in eastern lake was observed because of organic phosphorus mineralization. High linear discriminant analysis effect size of SRB and FeRB and the decreased Fe/Al-P in sediments indicated sulfide-mediated chemical iron reduction (SCIR) and FeRB-mediated microbial iron reduction mechanisms for internal phosphorus release during late algal blooms. The observed seasonal pattern of P-cycling-related microbes and its mediation on internal phosphorus release provides a foundation for internal P management in Lake Chaohu.
了解湖泊理化性质、内部养分循环及相关微生物之间的耦合关系是控制淡水富营养化的关键。本研究分析了中国富营养化巢湖沉积物 - 水界面（SWI）微生物的季节变化，以揭示沉积物中与磷（P）循环相关微生物的变化及其与蓝藻生命周期内磷内部释放的关联。鉴定出的与磷循环相关的微生物包括解磷细菌（PSB）（以芽孢杆菌属、硫杆菌属和不动杆菌属为主）、硫酸盐还原细菌（SRB）（以Sva0081_沉积物_组、未分类的c__热脱硫弧菌目和脱硫腺菌属为主）和铁还原细菌（FeRB）（以地热杆菌属、厌氧粘细菌属、嗜热厌氧芽孢杆菌属和严格梭菌属1为主）。从底栖阶段到蓝藻初始生长阶段，PSB增加，铁铝结合磷（Fe/Al - P）和钙结合磷（Ca - P）比例降低，表明内部磷通过PSB溶解Fe/Al - P和Ca - P而释放。蓝藻生长伴随着早期水华期间蓝藻的死亡、沉积和降解，这增加了由高有机质导致的SRB以及西湖中磷的净沉积。相反，由于有机磷矿化，东湖出现了磷释放。SRB和FeRB的高线性判别分析效应大小以及沉积物中Fe/Al - P的降低表明，在水华后期存在硫化物介导的化学铁还原（SCIR）和FeRB介导的微生物铁还原机制促进内部磷释放。观察到的与磷循环相关微生物的季节模式及其对内部磷释放的介导作用为巢湖的内部磷管理提供了基础。
