Biodegradation of asphaltene by lipopeptide-biosurfactant producing hydrocarbonoclastic, crude oil degrading Bacillus spp.

Asphaltene is the most recalcitrant compound in crude oil. Bacteria were isolated from crude oil contaminated soil and their efficiency for hydrocarbon degradation was determined using GC-MS and isolates were screened for biosurfactant production using FT-IR. Two Bacillus spp. having hydrocarbonoclastic and lipo-peptide biosurfactant-producing abilities were experimented for their asphaltene removal potential through oil removal efficiency (ORE%) and asphaltene degradation efficiency (ADE%). B. thuringeinsis SSL1 and B. cereus SSL3 could degrade 76.4% and 67.4% of asphaltene (20 g L- 1), in vitro, respectively, which is much higher than previous reports. B. thuringiensis SSL1 is recommended for effective breakdown of asphaltene, total petroleum hydrocarbon, and polyaromatic hydrocarbon degradation, aided by its biosurfactants, which is useful for crude oil cleanup. Biosurfactants are important for enhancing the availability of hydrophobic hydrocarbons to bacteria, which is beneficial for efficient crude oil remediation. These findings could lead to more effective strategies for complete clean-up of crude oil pollution.

Automated summary

Bacteria isolated from crude oil contaminated soil were tested for their hydrocarbon degradation efficiency and biosurfactant production. Two Bacillus spp. showed high potential for asphaltene degradation. B. thuringeinsis SSL1 is recommended for effective breakdown of asphaltene, aiding in crude oil cleanup.