Comparative genomics and metabolic modelling of oil-degrading Acinetobacter venetianus strains: clues into microbial degradation

Alkanes are the major components of crude oils and are found in oil-contaminated environments. Aerobic n-alkane degradation is a widespread phenomenon in nature, and several microbial strains and enzymes involved in their degradation have been identified and studied in detail. Recently, a novel species belonging to the Acinetobacter genus (A. venetianus) was described and preliminary analyses revealed the ability of strains belonging to this species to grow in the presence of diesel fuel, suggesting the possibility to exploit these microorganisms for bioremediation. We have performed a comprehensive multi-level analysis of six strains belonging to the A. venetianus species (VE-C3, RAG-1T, LUH13518, LUH7437, LUH8758, LUH5627) including i) exhaustive phenotypic characterization, ii) genomes sequencing and comparative genomics, iii) phenomics (i.e. phenotype microarray) analysis. The integration of these sources of information allowed establishing connections between the genomic context of each strain and their phenotypic features (i.e. their different alkanes degradation efficiency) and identifying some of the possible genetic bases of observed diversity. These, in turn, represent valuable targets for further experimental characterization. Additionally one of the strains (RAG-1T) was selected for metabolic network reconstruction and in silico metabolic modelling, allowing the identification of possible strategies for improved alkane degradation and biosurfactant production.