Biodegradation of n-alkanes by Pseudomonas aeruginosa and Actinobacterial (Indigenous Bacteria) in Bilge Water

The objective of this study was to evaluate the degradation efficiency of n-alkanes by a mixture of two Gram-positive strains and one Gram-negative strain. The methodology consisted in adapting an inoculum of bilge water, in an aqueous solution enriched with petroleum diesel, nutrients, and air for 15 days at 22°C. Then, 03 indigenous strains were isolated and identified, two Gram-positive bacteria were mixed and the Gram-negative strain was separated. Each group was inoculated separately into aerated reactors containing bilge water for 7 days. Finally, the $\mathrm{C}_{5}-\mathrm{C}_{10}, \mathrm{C}_{10}-\mathrm{C}_{28}$, and $\mathrm{C}_{25}-\mathrm{C}_{40}$ fractions were quantified by gas chromatography-FID to calculate the removal achieved. The results showed the presence of Rhodococcus spp., Micrococcus spp., and Pseudomona aeruginosa. These indigenous bacteria produced emulsions with each treatment. Pseudomona aeruginosa removed 91.9% of the short chains $(\mathrm{C}_{5-}\mathrm{C}_{10})$ and 86% of the long chains $(\mathrm{C}_{10}-\mathrm{C}_{40})$. While Actinobacteria increased the removal from 55.3% $(\mathrm{C}_{5}-\mathrm{C}_{10})$ to 65% $(\mathrm{C}_{10}-\mathrm{C}_{40})$. This study shows the potential of these indigenous bacteria to remove n-alkanes from bilge water