Assessment of residual chlorine in soil microbial community using metagenomics

Chlorine-containing disinfectants have been widely used around the world for the prevention and control of the COVID-19 pandemic. However, at present, little is known about the impact of residual chlorine on the soil micro-ecological environment. Herein, we treated an experimental soil-plant-microbiome microcosm system by continuous irrigation with a low concentration of chlorine-containing water, and then analyzed the influence on the soil microbial community using metagenomics. After 14-d continuous chlorine treatment, there were no significant lasting effect on soil microbial community diversity and composition either in the rhizosphere or in bulk soil. Although metabolic functions of the rhizosphere microbial community were affected slightly by continuous chlorine treatment, it recovered to the original status. The abundance of several resistance genes changed by 7 d and recovered by 14 d. According to our results, the chlorine residue resulting from daily disinfection may present a slight long-term effect on plant growth (shoot length and fresh weight) and soil micro-ecology. In general, our study assisted with environmental risk assessments relating to the application of chlorine-containing disinfectants and minimization of risks to the environment during disease control, such as COVID-19. (C) Higher Education Press 2022

Automated summary

This study investigated the impact of residual chlorine on soil microbial communities. The results showed that continuous chlorine treatment did not have a lasting effect on the diversity and composition of soil microbial communities, and slightly affected the metabolic functions of rhizosphere microbial communities, which later recovered to their original status. Due to the potential slight long-term effects on plant growth and soil micro-ecology, conducting environmental risk assessments and minimizing risks to the environment are crucial.