Heterogeneous bacterial communities affected by phytoplankton community turnover and microcystins in plateau lakes of Southwestern China

Qi Liu; Hucai Zhang; Yang Zhang; Donglin Li; Youhong Gao; Haoyu Li; Lizeng Duan; Xiaonan Zhang; Fengwen Liu; Jing Xu; Tianbao Xu; Huayu Li

doi:10.1016/j.scitotenv.2023.166303

Heterogeneous bacterial communities affected by phytoplankton community turnover and microcystins in plateau lakes of Southwestern China

Sci Total Environ. 2023 Dec 10:903:166303. doi: 10.1016/j.scitotenv.2023.166303. Epub 2023 Aug 15.

Authors

Qi Liu¹, Hucai Zhang², Yang Zhang¹, Donglin Li¹, Youhong Gao¹, Haoyu Li¹, Lizeng Duan¹, Xiaonan Zhang¹, Fengwen Liu¹, Jing Xu¹, Tianbao Xu³, Huayu Li¹

Affiliations

¹ Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan 650500, China.
² Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan 650500, China; Southwest United Graduate School, Kunming, 650500, Yunnan, China. Electronic address: zhanghc@ynu.edu.cn.
³ Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science, Yunnan University, Kunming, Yunnan 650500, China; Southwest United Graduate School, Kunming, 650500, Yunnan, China.

PMID: 37586523
DOI: 10.1016/j.scitotenv.2023.166303

Abstract

Both phytoplankton and bacteria are fundamental organisms with key ecological functions in lake ecosystems. However, the mechanistic interactions through which phytoplankton community change and bacterial communities interact remain poorly understood. Here, the responses of bacterial communities to the community structure, resource-use efficiency (RUE), and community turnover of phytoplankton and microcystins (MCs) were investigated in Lake Dianchi, Lake Xingyun, and Lake Erhai of Southwestern China across two seasons (May and October 2020). Among phytoplankton, Cyanobacteria was the dominant species in all three lakes and attained greater dominance in October than in May due to variation in the RUE of nitrogen and phosphorus and environmental changes. The production of MCs, including MC_LR, MC_RR and MC_YR, was the result of the massive Cyanobacteria. Decreases in diversity and increases in heterogeneity were observed in the bacterial community structure. Nutrient levels, environmental factors and MCs (especially MC_YR) jointly affected the bacterial community in lakes, namely its diversity and community assembly. The cascading effects in lakes mediated by environmental conditions, phytoplankton community composition, RUE, community turnover, and MCs on bacterial communities were revealed in this study. These findings underscore the importance of relating phytoplankton community change and MCs to the bacterial community, which is fundamental for better understanding the lake ecosystem functioning and potential risks of MCs.

Keywords: Bacterial community; Community turnover; Diversity; Microcystins; Phytoplankton; Resource-use efficiency.