Bovine Manure as a Rich Source for Isolation of Halo-Tolerant Bacterial Strains Capable of PAHs Biodegradation in Slurry Bioreactor

Abstract

This study aimed to isolate a bacterial consortium that capable of decomposing PAHs. Three halo-tolerant bacterial strains of Microbacterium paraoxydans B3F (S1), Stenotrophomonas N3 (S2), and Citrobacter NB2 (S3) were isolated from bovine manure. The isolate Microbacterium paraoxydans B3F showed the least resistance to salinity and growth not observed at 2 and 2.5% of NaCl, while isolate Citrobacter NB2 indicated growth in all salinity levels. The PHE biodegradation was more efficient in bacterial consortium compared to pure culture. At the end of the 35th day, the removal efficiency of PHE with an initial concentration of 100 mg/kg for seed volumes of 2, 10, and 20 mL was 33%, 50%, 52%, respectively. The TPHs biodegradation efficiencies at different soil/water ratios of 25%, 50% and 100% were 12%, 28.7 % and 60.8%, respectively. Three halo-tolerant bacteria were isolated from Bovine manure were efficiently used for bioremediation of phenanthrene.