Isolation and identification of the Raoultella ornithinolytica-ZK4 degrading pyrethroid pesticides within soil sediment from an abandoned pesticide plant

Xiaoqing Zhang,Bihua Duan,Kuai Liu,Xinxin Xia,Xiangxiang Hao,Shanshan Huo,Wanzhong Lin

doi:10.1007/s00203-019-01686-0

Abstract

We examined how Raoultella ornithinolytica-ZK4 degraded pyrethroid pesticides within soil sediment from an abandoned pesticide plant. Lambda-cypermethrin and deltamethrin are two pyrethroid insecticides with high insecticidal activity and a wide range of applications. However, their increased use has raised concerns regarding toxicity and accumulation. We isolated a strain of ZK4 (Raoultella ornithinolytica-ZK4) from soil taken from a channel that surrounded a pesticide plant. We used enzyme localization to study degrading bacteria ZK4. The ZK4 strain underwent intracellular enzyme degradation. The degradation rates of lambda-cyhalothrin and deltamethrin were 55% and 53%, respectively. The optimum pH of the two kinds of pyrethroids in ZK4 was 6.5, and their optimum temperature was 37 °C. The intracellular degradation of the crude enzyme produced by the ZK4 strain had a pH of 6.0–8.0 and a temperature of 20–42 °C. The ZK4 strain genome contained 5310 genes with a total length of 4,864,494 bp. Sugar metabolism and exogenous chemical metabolism accounted for the largest proportion of metabolic activities. We used the clusters of orthologous groups (COG) alignment and found numbers for 4686 protein sequences, accounting for 88.25% of the total predicted protein. ZK4 degraded lambda-cyhalothrin and deltamethrin, and may serve as a reference for the preparation of future degrading microbial agents to assist with environmental restoration efforts.

Highlights

Pyrethroid is the second largest class of insecticides, other than organophosphorus pesticides, and accounts for about 20% of the global pesticide market
We further examined the degradation effect of the crude enzyme extract on deltamethrin and lambda-cyhalothrin using Gas chromatography (GC)
Using Pseudomonas aeruginosa (KB) as a control, we determined the degrading rates of two pyrethroid pesticides under identical conditions for each of the selected three bacterial strains

Summary

Introduction

Pyrethroid is the second largest class of insecticides, other than organophosphorus pesticides, and accounts for about 20% of the global pesticide market. Deltamethrin and lambda-cyhalothrin are pyrethroid insecticides with high insecticidal activity. They are used to control various pests and are highly efficient, low cost, and light stable. Deltamethrin accounts for 80.6% of all pesticides used to treat vegetables in Beijing (Huang et al 2008). Pyrethroid pesticides have accumulation toxicity, reproductive toxicity, and neurotoxicity. They are highly toxic to individual non-target organisms such as bees and silkworms, and certain aquatic organisms. Strategies for effective use of pyrethroids to reduce environmental damage are, of considerable interest

Methods

Results

Discussion

Conclusion