Biodegradation of petroleum hydrocarbons using a novel bacterial strain isolated from hydrocarbons contaminated soil of Saudi Arabia

Petroleum spills pose a significant environmental threat, underscoring the need for efficient pollution removal methods. Bioremediation, employing bacterial cultures, emerges as a costeffective and eco-friendly technique. The success of this method hinges on whether petroleum pollution is eliminated or converted into a harmless form. This study seeks to isolate a bacterial strain exhibiting excellent capacity for degrading petroleum hydrocarbons. Biochemical tests and 16S rRNA results identified various Microbacterium spp., namely Microbacterium barkeri (SA9) and Microbacterium deserti (SA2, SA3, SA5, and SA7), isolated from hydrocarbon-contaminated soil. Within five days, these strains demonstrated degradation percentages of 20.91%, 38.51%, 77.68%, 22.51%, and 31.11% for petroleum, respectively. Phylogenetic and sequence analyses targeting the 16S rRNA gene revealed that M. barkeri (accession number ON 421582) is closely related to strains from India and Saudi Arabia, while M. deserti (ON 421525, ON 421524, ON 421523, and ON 421522) shares affinity with strains from Saudi Arabia, China, and India. Furthermore, these isolates produced a stable emulsion with E-24% of 25% for 72 h. Notably, this marks the first study exploring the use of these bacterial strains for petroleum bioremediation in Saudi Arabia.