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

摘要

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.