A highly potent benzene-degrading bacterial strain from petroleum-contaminated soils: isolation and characterization

Abstract

Benzene is an essential component of crude oil and petroleum products. Given its toxicity, it is imperative to eliminate benzene when it leaks into the environment. Microorganisms is a sustainable, eco-friendly, and cost-effective tool to remove benzene in soil and water. In this study, a noval Pseudomonas mendocina strain (DBH1) was isolated from an oil-contaminated soil in China and characterized for its ability to degrade benzene. The results of culture experiments shown that Pseudomonas mendocina DBH1 was capable of completely degrading benzene, toluene and ethylbenzene within 24 h under pure culture conditions with a substrate concentration of 200 mg L−1. Growth conditions optimization experiments shown DBH1 could grow fast at temperature ranging from 20 °C to 35 °C, pH levels between 6 and 7, and retained biological activity at high benzene concentration (1000 mg L−1). In particular, more than 50% of the benzene could be degraded after 40 h of incubation when the benzene concentration was 800 mg L−1 at the optimum condition. Pseudomonas mendocina DBH1 exhibited a high growth rate, high efficiency, good tolerance, and mild reaction conditions, rendering it a promising candidate for the bioremediation of benzene and other benzene-related compounds. It would be beneficial to conduct further research to elucidate the metabolic pathways of Pseudomonas mendocina DBH1 and to establish specific microbial consortia that can remediate petroleum-contaminated soils more efficiently.