Isolation of a diazinon-degrading strain Sphingobium sp. DI-6 and its novel biodegradation pathway

Guangli Wang; Xiang Li; Jiaxin Zheng; Xuedong Li; Lingling Bai; Wenlong Yue; Li Jiang

doi:10.3389/fmicb.2022.929147

Isolation of a diazinon-degrading strain Sphingobium sp. DI-6 and its novel biodegradation pathway

Front Microbiol. 2022 Aug 23:13:929147. doi: 10.3389/fmicb.2022.929147. eCollection 2022.

Authors

Guangli Wang¹, Xiang Li¹, Jiaxin Zheng¹, Xuedong Li¹, Lingling Bai¹, Wenlong Yue², Li Jiang³

Affiliations

¹ Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, School of Life Sciences, Huaibei Normal University, Huaibei, China.
² Laboratory of Applied Microbiology and Biotechnology, School of Pharmaceutical Engineering & Life Science, Changzhou University, Changzhou, China.
³ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi, China.

Abstract

Diazinon is one of the most widely used organophosphate insecticides, one that is frequently detected in the environment. In this study, a diazinon-degrading bacterium, DI-6, previously isolated from diazinon-contaminated soil in China has been subsequently identified as Sphingobium sp. on the basis of its physiological and biochemical characteristics, as well as by virtue of a comparative analysis of 16S rRNA gene sequences. This strain is capable of using diazinon as its sole carbon source for growth and was able to degrade 91.8% of 100 mg L^-1 diazinon over a 60-h interval. During the degradation of diazinon, the following seven metabolites were captured and identified by gas chromatography/mass spectrometry (GC-MS) analysis: diazoxon, diazinon aldehyde, isopropenyl derivative of diazinon, hydroxyethyl derivative of diazinon, diazinon methyl ketone, O-[2-(1-hydroxyethyl)-6-methylpyrimidin-4-yl] O-methyl O-hydrogen phosphorothioate, and O-(6-methyl pyrimidin-4-yl) O,O-dihydrogen phosphorothioate. Based on these metabolites, a novel microbial biodegradation pathway of diazinon by Sphingobium sp. DI-6 is proposed. This research provides potentially useful information for the application of the DI-6 strain in bioremediation of diazinon-contaminated environments.

Keywords: 16S rRNA; Sphingobium sp. DI-6; diazinon-biodegradation metabolites; environmental remediation; novel metabolic pathway.

Grants and funding

This work was supported by the National Key Research and Development Program of China (2018YFD1000903), the Provincial Natural Science Foundation of Anhui (2108085MC70), and the Natural Science Foundation from the Educational Commission of Anhui Province (KJ2020204).