Expression of Rhodococcus erythropolis stress genes in planctonic culture supplemented with various hydrocabons

Abstract

Studying Rhodococcus erythropolis stress response is of significant scientific interest, since this microorganism is widely used for bioremediation of oil-contaminated sites and is essential for environmental biotechnology. In addition, much less data was published on molecular mechanisms of stress resistance and adaptation to effects of pollutants for Gram-positive oil degraders compared to Gram-negative ones. This study provided an assessment of changes in the transcription level of the soxR, sodA, sodC, oxyR, katE, katG, recA, dinB, sigF, sigH genes in the presence of decane, hexadecane, cyclohexane, benzene, naphthalene, anthracene and diesel fuel. Judging by the changes in the expression of target genes, hydrocarbons as the main carbon source caused oxidative stress in R. erythropolis cells, which resulted in DNA damage. It was documented by enhanced transcription of genes encoding antioxidant enzymes (superoxide dismutase and catalase), SOS response, DNA polymerase IV, and sigma factors of RNA polymerase SigH and SigF. At this, it was likely that in the presence of hydrocarbons, transcription of catalase genes (katE and katG) was coordinated primarily by the sigF regulator.