Isolation and characterization of a novel bacterial strain Cytobacillus firmus RP5 for the degradation of petroleum hydrocarbons

Rapid industrial growth has resulted in the discharge of a wide range of pollutants into natural water bodies, leading to a significant decline in water quality. Bioremediation with unique indigenous microbial flora has been identified as a promising strategy for removing and degrading harmful contaminants. In this regard, we planned a study to identify and isolate a non-pathogenic, biosurfactant-producing, antibiotic-sensitive bacterium from industrial effluents taken from Baddi, an industrial town in Himachal Pradesh, India. A number of biochemical and morphological tests, 16S rRNA sequencing, and phylogenetic analysis were used to confirm that the bacterial strain was Cytobacillus firmus RP5. The oil spreading , drop collapse, and emulsification index tests showed that C. firmus RP5 produced biosurfactant. GC-FID revealed that the isolated strain degraded three petroleum hydrocarbons (n-hexadecane, kerosene, and diesel) by more than 90% after 14 days. The antibiotic susceptibility tests verified that the bacterium is susceptible to antibiotics, thereby minimizing the possibility of antibiotic resistance spreading. Additionally, the bacterial strain is non-pathogenic to humans. Its high efficacy in breaking down hydrocarbons (95-99%) within 14 days demonstrates its immense potential for degrading petroleum pollutants. The results indicate that C. firmus RP5 could be useful in removing petroleum pollutants released into water bodies, hence improving the quality of the water.