Efficient degradation of ivermectin by newly isolated Aeromonas taiwanensis ZJB-18,044

• DOI: 10.1007/s10532-020-09909-8
• Publication Date: 2020-09-16T05:02:30Z
• Authors: Yuanshan Wang; Meihua Gong; Xianlin Wang; Xiaolun Peng; Yuwei Wang; Jiahui Guan; Dongyuan Cheng; Chunyue Weng; Yuguo Zheng
• Keywords: 0301 basic medicine; Original Paper; 03 medical and health sciences; Biodegradation, Environmental; Ivermectin; Antiparasitic Agents; Aeromonas; 3. Good health

Ivermectin (IVM) is a widely used antiparasitic agent and acaricide. Despite its high efficiency against nematodes and arthropods, IVM may pose a threat to the environment due to its ecotoxcity. In this study, degradation of IVM by a newly isolated bacterium Aeromonas taiwanensis ZJB-18,044 was investigated. Strain ZJB-18,044 can completely degrade 50 mg/L IVM in 5 d with a biodegradation ability of 0.42 mg/L/h. Meanwhile, it exhibited high tolerance (50 mg/L) to doramectin, emamectin, rifampicin, and spiramycin. It can also efficiently degrade doramectin, emamectin, and spiramycin. The IVM degradation of strain ZJB-18,044 can be inhibited by erythromycin, azithromycin, spiramycin or rifampicin. However, supplement of carbonyl cyanide m-chlorophenylhydrazone, an uncoupler of oxidative phosphorylation, can partially recover the IVM degradation. Moreover, strain ZJB-18,044 cells can pump out excess IVM to maintain a low intracellular IVM concentration. Therefore, the IVM tolerance of strain ZJB-18,044 may be due to the regulation of the intracellular IVM concentration by the activated macrolide efflux pump(s). With the high IVM degradation efficiency, A. taiwanensis ZJB-18,044 may serve as a bioremediation agent for IVM and other macrolides in the environment.