Oily Sludge Bioremediation and Simultaneous Production of Polyhydroxyalkanoate by Novel Hydrocarbon Degrading Bacterial Consortium

For sustainable waste management along with bioresource recovery, oily sludge waste was exploited for microbial polyhydroxyalkanoate (PHA) production. Nine bacterial strains with the capacity to grow fast, having high sodium benzoate and crude oil degradation potential as well as Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] production was used for consortium development. Five different bacterial consortia were designed and analyzed for 1% oily sludge degradation and PHA production. The Fourier Transform Infrared (FTIR) interferogram and proton nuclear magnetic Resonance (HNMR) spectra of extracted PHA from 5 consortia indicated that all consortia produced P(3HB-co-3HV) copolymeric type of PHA naturally. A consortium of five strains (Achromobacter xylosoxidans ASSphn63, Pannonibacter phragmitetus AWSant32, Pseudomonas aeruginosa ASSphn611, Acinetobacter lwoffii AWSant35 and Ochrobactrum ciceri AWIS01) was found to be the most efficient. It showed 84.8% P(3HB-co-3HV) accumulation relative to their cell dry weight and 85.7% of total petroleum hydrocarbon degradation when provided with 1% oily sludge as carbon source. Thermal analysis of P(3HB-co-3HV) extracted from this consortium showed 94.7 degrees C melting temperature (Tm) and 93.38% crystallinity (%Xc). To the best of our knowledge this is the first report of bacterial consortium showing oily sludge degradation with coproduction of biopolymer, providing an upcoming approach for sustainable oily sludge waste management with a useful byproduct formation.