The sensitivity and stability of bacterioplankton community structure to wind-wave turbulence in a large, shallow, eutrophic lake

Jian Zhou,Zhiping Wang,Decai Jin,Boqiang Qin,Xiaoxia Han

doi:10.1038/s41598-017-17242-z

Abstract

Lakes are strongly influenced by wind-driven wave turbulence. The direct physical effects of turbulence on bacterioplankton community structure however, have not yet been addressed and remains poorly understood. To examine the stability of bacterioplankton communities under turbulent conditions, we simulated conditions in the field to evaluate the responses of the bacterioplankton community to physical forcing in Lake Taihu, using high-throughput sequencing and flow cytometry. A total of 4,520,231 high quality sequence reads and 74,842 OTUs were obtained in all samples with α-proteobacteria, γ-proteobacteria and Actinobacteria being the most dominant taxa. The diversity and structure of bacterioplankton communities varied during the experiment, but were highly similar based on the same time of sampling, suggesting that bacterioplankton communities are insensitive to wind wave turbulence in the lake. This stability could be associated with the traits associated with bacteria. In particular, turbulence favored the growth of bacterioplankton, which enhanced biogeochemical cycling of nutrients in the lake. This study provides a better understanding of bacterioplankton communities in lake ecosystems exposed to natural mixing/disturbances.

Highlights

Different microbiological studies aiming at biomedical, environmental, agricultural, and bioenergy applications share a common challenge: predict how microbial community functions and composition respond to disturbances[1]
We wondered how do the changes of bacterial community composition (BCC) and function affect the matter degradation and nutrient cycling, and affect the growth of phytoplankton
To address these knowledge gaps, we investigated the changes in bacterial community composition and their abundances under wind-driven wave turbulent conditions in a large, shallow, and eutrophic lake concordant with cyanobacterial bloom periods

Summary

Introduction

Different microbiological studies aiming at biomedical, environmental, agricultural, and bioenergy applications share a common challenge: predict how microbial community functions and composition respond to disturbances[1]. Climate change, which has repercussions on the world’s atmospheric system and weather patterns, may change the hydrodynamics of aquatic systems by increasing the frequency and intensity of tropical cyclones[18,19] These physical disturbances strongly affect the stability of the water column and turbulent conditions in lakes. This highlights the importance of understanding the ecology of bacterioplankton community To address these knowledge gaps, we investigated the changes in bacterial community composition and their abundances under wind-driven wave turbulent conditions in a large, shallow, and eutrophic lake concordant with cyanobacterial bloom periods. We used high-throughput Illumina MiSeq sequencing and flow cytometry to generate profiles of the BCC before, during, and after exposure to turbulence This approach has enabled us to examine the growth of bacterioplankton, and their community composition and potential roles in driving algal blooms under wind wave environments. Understanding the effects of turbulence on bacterial community across time and space will provide further insights into the ecology of microorganisms, as well as enhance the ability to predict microbial responses to environmental changes, especially in the wake of the changing climate[8]

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Results

Conclusion