Construction of potential bacterial consortia for efficient hydrocarbon degradation

Hydrocarbon-degrading bacteria were isolated from 2% hydrocarbon enriched sample collected from vehicular repairing stations, garages and petrol bunk. Incubation of the isolated non-virulent strains in Bushnell-Haas (BH) medium supplemented with hydrocarbon, showed their ability to survive on hydrocarbon thereby reducing the total organic carbon content. Based on the degradation potential, different bacterial consortia were prepared and consortium CHM1 was found to grow best with maximum degradation. 16S rRNA gene sequencing of the strains revealed their identity with Kiebsiella spp., Enterobacter sp. and Pantoea sp. high to moderate affinity towards hydrocarbon of the selected strains were indicated by Bacterial Adhesion To Hydrocarbon (BATH) test and Contact Angle. Gas Chromatography-Mass Spectrometric (GC-MS) analysis of the mixed hydrocarbon containing broth revealed the presence of benzene derivatives, aliphatic acids, naphthalene, aliphatic alkanes, cyclic aliphatics as major compounds. The efficiency of the selected bacterial consortium showed an overall 16.20% degradation of the mixed hydrocarbon after 4 days, where, aliphatic cyclic compound (1-(1,5-Dimethylhexyl)-4-(4-Methylpenty1)-Cyclohexane) were completely degraded, naphthalene derivatives were reduced to 36.72%, aliphatic acids were degraded to 78.13% and benzene derivatives to 24.16%. Degradation of the long-chain aliphatic alkanes was further observed through Fourier Transform Infrared spectrometric (FTIR) analysis.