Journal Article

Metabolic responses of Rhodococcus erythropolis PR4 grown on diesel oil and various hydrocarbons

Perei, Katalin, Rákhely, Gábor, Hegedüs, Botond, Maróti, Gergely, Laczi, Krisztián, Kis, Ágnes, Horváth, Balázs

2015

Overview

Rhodococcus erythropolis PR4 is able to degrade diesel oil, normal-, iso- and cycloparaffins and aromatic compounds. The complete DNA content of the strain was previously sequenced and numerous oxygenase genes were identified. In order to identify the key elements participating in biodegradation of various hydrocarbons, we performed a comparative whole transcriptome analysis of cells grown on hexadecane, diesel oil and acetate. The transcriptomic data for the most prominent genes were validated by RT-qPCR. The expression of two genes coding for alkane-1-monooxygenase enzymes was highly upregulated in the presence of hydrocarbon substrates. The transcription of eight phylogenetically diverse cytochrome P450 (cyp) genes was upregulated in the presence of diesel oil. The transcript levels of various oxygenase genes were determined in cells grown in an artificial mixture, containing hexadecane, cycloparaffin and aromatic compounds and six cyp genes were induced by this hydrocarbon mixture. Five of them were not upregulated by linear and branched hydrocarbons. The expression of fatty acid synthase I genes was downregulated by hydrocarbon substrates, indicating the utilization of external alkanes for fatty acid synthesis. Moreover, the transcription of genes involved in siderophore synthesis, iron transport and exopolysaccharide biosynthesis was also upregulated, indicating their important role in hydrocarbon metabolism. Based on the results, complex metabolic response profiles were established for cells grown on various hydrocarbons. Our results represent a functional annotation of a rhodococcal genome, provide deeper insight into molecular events in diesel/hydrocarbon utilization and suggest novel target genes for environmental monitoring projects.

• Publisher: Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: acetates / Acetates - metabolism / Acetic acid / Actinomycetes / Alkanes / Alkanes - metabolism / Analysis / Annotations / Aromatic compounds / Aromatic hydrocarbons / Bacteria / Biodegradation / Biological research / Biomedical and Life Sciences / Biosynthesis / Biotechnology / Biotransformation / Chemical properties / Chemical reactions / Cycloalkanes / Cytochrome / cytochrome P-450 / Cytochrome P450 / Cytochromes P450 / Diesel / diesel fuel / Diesel fuels / DNA / Environmental monitoring / Exopolysaccharides / Fatty acids / Fatty-acid synthase / Gasoline / Gene Expression Profiling / gene expression regulation / Genes / Genomes / Genomics / Hexadecane / Hydrocarbons / Life Sciences / Metabolic Networks and Pathways - genetics / Metabolic response / Metabolism / Microbial Genetics and Genomics / Microbiology / Mixtures / Molecular weight / Nucleotide sequence / Observations / Oil / Oils & fats / Oils - metabolism / Oxidation / Oxygenase / PCB / phylogeny / Polychlorinated biphenyls / Proteomics / quantitative polymerase chain reaction / Real-Time Polymerase Chain Reaction / reverse transcriptase polymerase chain reaction / Rhodococcus / Rhodococcus - genetics / Rhodococcus - growth & development / Rhodococcus - metabolism / Rhodococcus erythropolis / siderophores / Studies / Sulfur content / Transcriptomes / Transcriptomics