Cyclohexane, naphthalene, and diesel fuel increase oxidative stress, CYP153, sodA, and recA gene expression in Rhodococcus erythropolis.

Ivan Sazykin,Marina Sazykina,Ludmila Khmelevtsova,Ekaterina Seliverstova,Maksim Makarenko,Alexander Rakin

doi:10.1002/mbo3.855

Ivan Sazykin, Marina Sazykina + Show 4 more

Open Access

https://doi.org/10.1002/mbo3.855

Copy DOI

Abstract

In this study, we compared the expression of CYP153, sodA, sodC, and recA genes and ROS generation in hydrocarbon‐degrading Rhodococcus erythropolis in the presence of cyclohexane, naphthalene, and diesel fuel. The expression of cytochrome P450, sodA (encoding Fe/Mn superoxide dismutase), recA, and superoxide anion radical generation rate increased after the addition of all studied hydrocarbons. The peak of CYP153, sodA, and recA gene expression was registered in the presence of naphthalene. The same substrate upregulated the Cu/Zn superoxide dismutase gene, sodC. Cyclohexane generated the highest level of superoxide anion radical production. Hydrogen peroxide accumulated in the medium enriched with diesel fuel. Taken together, hydrocarbon biotransformation leads to oxidative stress and upregulation of antioxidant enzymes and CYP153 genes, and increases DNA reparation levels in R. erythropolis cells.

Highlights

Hydrocarbon‐ and xenobiotic‐degrading bacteria display enormous plasticity against utilized substrates
For superoxide anion radical assay, microorganisms were grown overnight (18 hr) in the basic mineral salt medium complemented of 0.5% of yeast extract and 0.5% of tryptone
For culture of R. erythropolis grown in the basic mineral salt medium complemented of 0.5% of yeast extract with the addition of 2% w/v of the investigated hydrocarbons or glucose, the growth curves were built (Appendix 1, Figure A1)

Summary

Introduction

Hydrocarbon‐ and xenobiotic‐degrading bacteria display enormous plasticity against utilized substrates. These microorganisms are ca‐ pable of transforming various types of hydrocarbons, their halogen and nitro derivates, pesticides, plastics such as PET and polyeth‐ ylene, etc. Bacterial cells suffer from an oxidative stress, utilizing such compounds. Bacteria are unlikely to possess multiple substrate‐specific enzyme systems for oxidation of each compound. Bacteria constantly contact oil in natural conditions. Oil is a natural mix composed of more than 1,500 separate substances. Emerging of xenobiotic oxidases is even more uncommon, taking into account that xenobiotics are chemical compounds foreign to bacteria with no history of previous contacts

Objectives

Findings

Discussion

Conclusion