Early warning of MIB episode based on gene abundance and expression in drinking water reservoirs

Tengxin Cao; Jiao Fang; Zeyu Jia; Yiping Zhu; Ming Su; Qi Zhang; Yichao Song; Jianwei Yu; Min Yang

doi:10.1016/j.watres.2023.119667

Early warning of MIB episode based on gene abundance and expression in drinking water reservoirs

Water Res. 2023 Mar 1:231:119667. doi: 10.1016/j.watres.2023.119667. Epub 2023 Jan 26.

Authors

Tengxin Cao¹, Jiao Fang², Zeyu Jia³, Yiping Zhu⁴, Ming Su⁵, Qi Zhang⁶, Yichao Song⁴, Jianwei Yu⁷, Min Yang⁸

Affiliations

¹ Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing, 100049, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China.
³ Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; Yangtze Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing, 100038, China.
⁴ Yangtze Eco-Environment Engineering Research Center, China Three Gorges Corporation, Beijing, 100038, China.
⁵ Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: mingsu@rcees.ac.cn.
⁶ Institute of Hydrobiology, Chinese Academy of Sciences, No. 7 Donghu South Road, Wuchang, Wuhan, 430072, China.
⁷ Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; National Engineering Research Center of Industrial Wastewater Detoxication and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
⁸ Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; Shanghai Chengtou Raw Water Co. Ltd., Beiai Rd. 1540, Shanghai, 200125, China; University of Chinese Academy of Sciences, Beijing, 100049, China. Electronic address: yangmin@rcees.ac.cn.

PMID: 36724724
DOI: 10.1016/j.watres.2023.119667

Abstract

Cellular 2-methylisoborneol (MIB) yield of cyanobacteria varies under different conditions according to culture studies and field investigations, the causal mechanism remains unclear and results in ineffective MIB prediction. Through an intensive field survey during an MIB episode produced by Pseudanabaena cinerea in QCS reservoir, we demonstrated that MIB synthesis (mic) gene abundance (DNA) and expression (RNA) might be useful as parameters for early warning of MIB production. It was found that the abundance of mic DNA and RNA peaked ahead of MIB concentrations by 10 and 7 days, respectively. In addition, the RNA abundance (R² = 0.45, p < 0.01) showed a slightly higher correlation with MIB compared to DNA abundance (R² = 0.37, p < 0.01), suggesting that the conditions for the growth of Pseudanabaena cinerea might be slightly different from those for mic gene expression, which was verified by a culture experiment. The highest cell growth was obtained under 36 μmol photons m^-2 s^-1, while the highest cellular MIB yield and mic gene expression level were obtained under 85 μmol photons m^-2 s^-1. Our results clearly supported that light intensity was the virtual regulator governing the mic gene expression within the controlled culture experiment and the actual MIB episode in the reservoir. Besides these results, we developed an early warning model using mic gene abundance as an indicator of MIB episodes, which was verified in two other reservoirs. Our findings highlight the effect of light intensity on mic gene expression and MIB synthesis and provide an early warning tool targeting MIB episode prediction, which therefore should be of importance for source water authorities.

Keywords: 2-methylisoborneol (MIB); Gene expression; Light intensity; MIB synthesis gene; Prediction; Pseudanabaena; Reservoir.

MeSH terms

Camphanes
Cyanobacteria* / metabolism
Drinking Water* / microbiology
Odorants / analysis
Water Supply

Substances

Drinking Water
Camphanes