Lv Jiaming, Yang Guijun, Zhang Yuqing, Shao Keqiang, Tang Xiangming
State Key Laboratory of Lakes and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, China.
College of Environment and Ecology, Jiangnan University, Wuxi, China.
PeerJ. 2025 Jul 16;13:e19704. doi: 10.7717/peerj.19704. eCollection 2025.
Cyanobacterial blooms present a significant global water challenge, often accumulating in lakeside wetlands and impacting water quality. Despite this, wetland characteristics influencing bacterial diversity during cyanobacterial bloom degradation remain unclear.
To address this gap, we conducted a 30-day simulation experiment near Lake Taihu, China, to investigate the effects of density, algae concentration and water velocity on bacterial diversity and water quality. An orthogonal design with three factors and levels was used with 18 tanks, each with a soil layer. density, algae concentration and water velocity were adjusted to simulate lake conditions. Physicochemical parameters were measured within a month, and water samples were collected for bacterial biomass and DNA extraction. Bacterial 16S rRNA gene sequencing was performed to assess diversity, and statistical analyses including α-diversity, β-diversity, and analysis of similarities (ANOSIM) were conducted to evaluate the impact of the experimental factors on water quality and bacterial community structures.
Algal concentration and water velocity had a greater impact on water quality than density. Employing 16S rRNA gene sequencing technology, we discovered that bacterial α-diversity was significantly affected by density, water velocity, and time ( < 0.01), whereas bacterial β-diversity was significantly influenced by algal concentration and time ( < 0.001). The bacterial community structure was significantly impacted by density, water velocity, algal concentration, and time ( < 0.001). During the degradation of cyanobacterial blooms, the most abundant bacteria were Proteobacteria (36.8%), Bacteroidetes (20.4%), Cyanobacteria (19.1%), and Actinobacteria (10.3%). Algal density had a stronger influence on bacterial community structure than density or water velocity. Orthogonal test results indicated that high algal concentration, coupled with reduced density and increased water velocity, rapidly decreased nitrogen, phosphorus concentrations, and bacterial diversity. These findings deepen our understanding of wetland effects on cyanobacterial blooms, offering insights for water ecological conservation and resource management in cyanobacteria-affected lakes.
蓝藻水华是全球重大的水问题，常积聚在湖滨湿地并影响水质。尽管如此，在蓝藻水华降解过程中影响细菌多样性的湿地特征仍不清楚。
为填补这一空白，我们在中国太湖附近进行了为期30天的模拟实验，以研究密度、藻类浓度和水流速度对细菌多样性和水质的影响。采用三因素三水平的正交设计，设置18个水箱，每个水箱都有一层土壤。调整密度、藻类浓度和水流速度以模拟湖泊条件。在一个月内测量理化参数，并采集水样用于细菌生物量和DNA提取。进行细菌16S rRNA基因测序以评估多样性，并进行包括α多样性、β多样性和相似性分析（ANOSIM）在内的统计分析，以评估实验因素对水质和细菌群落结构的影响。
藻类浓度和水流速度对水质的影响比密度更大。采用16S rRNA基因测序技术，我们发现细菌α多样性受密度、水流速度和时间的显著影响（P < 0.01），而细菌β多样性受藻类浓度和时间的显著影响（P < 0.001）。细菌群落结构受密度、水流速度、藻类浓度和时间的显著影响（P < 0.001）。在蓝藻水华降解过程中，最丰富的细菌是变形菌门（36.8%）、拟杆菌门（20.4%）、蓝藻门（19.1%）和放线菌门（10.3%）。藻类密度对细菌群落结构的影响比密度或水流速度更强。正交试验结果表明，高藻类浓度，再加上密度降低和水流速度增加，会迅速降低氮、磷浓度和细菌多样性。这些发现加深了我们对湿地对蓝藻水华影响的理解，并为受蓝藻影响湖泊的水生态保护和资源管理提供了见解。
