Salinity-mediated enhancement of quaternary ammonium compounds resistance and removal in endophytic bacteria LSE01

Xiao Xiao; Junjie Li; Xiaotong Wang; Lin Ding; Shengju Shen; Ting Liu; Zhong Ren; Xubiao Luo

doi:10.1016/j.envres.2024.118688

Salinity-mediated enhancement of quaternary ammonium compounds resistance and removal in endophytic bacteria LSE01

Environ Res. 2024 Mar 15;251(Pt 2):118688. doi: 10.1016/j.envres.2024.118688. Online ahead of print.

Authors

Xiao Xiao¹, Junjie Li², Xiaotong Wang¹, Lin Ding³, Shengju Shen¹, Ting Liu¹, Zhong Ren¹, Xubiao Luo⁴

Affiliations

¹ Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang 330063, PR China.
² The School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; China National Gold Group Jiangxi Mining Co., Ltd, Shangrao 334213, PR China.
³ Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang 330063, PR China. Electronic address: dinglin_hust@126.com.
⁴ Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, PR China; National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resources Utilization, Nanchang Hangkong University, Nanchang 330063, PR China. Electronic address: luoxubiao@126.com.

PMID: 38493855
DOI: 10.1016/j.envres.2024.118688

Abstract

The widespread usage of quaternary ammonium compounds (QACs) as disinfectants during the COVID-19 pandemic poses significant environmental risks, such as toxicity to organisms and the emergence of superbugs. In this study, different inorganic salts (NaCl, KCl, CaCl₂, MgCl₂) were used to induce endophytes LSE01 isolated from hyperaccumulating plants. After five generations of cultivation under 80 g/L NaCl, the minimum inhibitory concentration (MIC) of LSE01 to QACs increased by about 3-fold, while its degradation extent increased from 8% to 84% for C₁₂BDMA-Cl and 5%-89% for C₁₄BDMA-Cl. Transmission electron microscopy (TEM) and three-dimensional fluorescence spectra indicated that the cells induced by high concentration of salt caused plasmolysis and secreted more bound extracellular polymeric substances (B-EPS); these changes are likely to be an important reason for the observed increased resistance and enhanced degradation extent of LSE01 to QACs. Our findings suggest that salt-induction could be an effective way to enhance the resistance and removal of toxic organic pollutants by functional microorganisms.

Keywords: Biodegradation; Endophytes (LSE01); MIC; QACs; Salt-induction.