Occurrence and distribution of viruses and picoplankton in tropical freshwater bodies determined by flow cytometry

Yi Yang; Xiaoqiong Gu; Shu Harn Te; Shin Giek Goh; Kalaivani Mani; Yiliang He; Karina Yew-Hoong Gin

doi:10.1016/j.watres.2018.11.022

Occurrence and distribution of viruses and picoplankton in tropical freshwater bodies determined by flow cytometry

Water Res. 2019 Feb 1:149:342-350. doi: 10.1016/j.watres.2018.11.022. Epub 2018 Nov 13.

Authors

Yi Yang¹, Xiaoqiong Gu², Shu Harn Te¹, Shin Giek Goh², Kalaivani Mani¹, Yiliang He³, Karina Yew-Hoong Gin⁴

Affiliations

¹ NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore.
² Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore.
³ School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China.
⁴ NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore; Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore. Electronic address: ceeginyh@nus.edu.sg.

PMID: 30469020
DOI: 10.1016/j.watres.2018.11.022

Abstract

This study aimed to examine the drivers in shaping the occurrence and distribution of total viruses and picoplankton in tropical freshwater ecosystems. Flow cytometry was used to quantify the concentrations of total viruses, picoheterotrophs, picophytoplankton, and picocyanobacteria. Three land use patterns (urban-, agriculture- and parkland-dominated) were evaluated using ArcGIS. Significant correlations were observed between water-borne microbial targets and water quality parameters (0.175 ≤ |r| ≤ 0.441), nutrients (0.250 ≤ r ≤ 0.570) and land use factors (0.200 ≤ |r| ≤ 0.460). In particular, the concentrations of total viruses and picoheterotrophic cells were higher in catchments whereas the abundances of picophytoplankton and picocyanobacteria were higher in reservoirs. Total viruses and picoplankton had higher concentrations in urban- and agriculture-dominated areas, probably due to anthropogenic inputs and agricultural inputs, respectively. Although surface water is a complex matrix influenced by niche-based (i.e., physicochemical properties, nutrients, land use impact etc.) and neutral-based factors (i.e., ecological drift, dispersal and species), land use patterns could help to elucidate the occurrence and distribution of the total microbial community at the macroscopic level. Meanwhile, inter-correlations among viruses, picoplankton and picoheterotrophs (0.715 ≤ r ≤ 0.990) also substantiates their mutual interactions in influencing the microbial community. Furthermore, the relationships between total microbial cells and bacterial and viral indicators were also investigated. Concentrations of total viruses, picoplankton and picoheterotrophs were positively correlated with bacterial indicators (0.427 ≤ r ≤ 0.590) and viral indicators (0.201 ≤ r ≤ 0.563). These results indicated that faecal and viral contamination could contribute to the numbers of total viruses and bacteria.

Keywords: Cyanobacteria; Flow cytometry; Occurrence; Phytoplankton; Viruses.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Bacteria
Ecosystem*
Flow Cytometry
Fresh Water
Viruses*