Characterization of C16–C36 alkane degradation and oily sludge bioremediation by Rhodococcus erythropolis XP

Oil contamination poses significant risks to human health and ecosystems, emphasizing the importance of studying alkane biodegradation. In this study, we found that Rhodococcus erythropolis XP can utilize various alkanes, including C16–C36 n-alkanes and iso-alkane (pristane). The degradation capacity was significant, with over 95% of C20 degraded (500–2,500 mg/L) within 72 h. The bioremediation capacity in oily sludge was determined by a novel Low Pressure Gas Chromatography-Mass Spectrometry methodology especially for rapid analysis (within 12 min) of n-alkanes. Notable biodegradation of C14–C30 alkanes was observed in sludge treated with Rhodococcus erythropolis XP. In addition, metabolic intermediates of C16 and C20 were identified, indicating the presence of both terminal and subterminal pathways in Rhodococcus erythropolis XP. A new Baeyer-Villiger monooxygenase (BVMO_4041) was characterized, which catalyzes a key step in the subterminal pathway of alkane degradation. These results reflect the promise of Rhodococcus erythropolis XP in addressing the pressing need for efficient alkane degradation in contaminated environments.