Biosurfactant Production Potentials of Autochthonous Bacterial Species Associated with Waxy Crude Oil

Microbial degradation of paraffinic compounds has gained considerable interest due to their easy handling, eco-friendliness, high operational safety for sustainable development, low toxicity, non-carcinogenic nature, non-combustibility, and widespread presence of microorganisms. Biosurfactants increase bioavailability and help enhance contact between pollutants and microorganisms, thereby facilitating uptake and degradation, as well as the amelioration (remediation) of hydrocarbon-polluted environments. It also acts as a waxy depressant, enhancing the flow of crude during production. This study investigated the biosurfactant-producing potential of autochthonous bacterial species associated with waxy crude oil. The culturable autochthonous heterotrophic bacterial density in the waxy samples ranged from 1.3 ± 0.3 x 10<sup>4</sup> to 2.6 ± 0.3 x 10<sup>4</sup> CFU/ml. Four distinct bacterial species were isolated, characterized, and identified as <i>Bacillus cereus, B. subtilis, Pseudomonas aeruginosa, </i>and <i>Micrococcus </i>sp. Analysis of the biosurfactant potentials of the isolates cell-free supernatants revealed varying biosurfactant potentials, with <i>Pseudomonas aeruginosa</i> culture extract having the best oil spread result and biosurfactant potential (% EC<sub>24</sub> = 52.05), followed by <i>B. subtilis </i>(% EC<sub>24</sub> = 50.0), then <i>Micrococcus </i>sp. (% EC<sub>24</sub> = 48.7) and <i>B. cereus </i>(% EC<sub>24</sub> = 47.5). All the isolates' cell-free extracts exhibited β-hemolysis. The potential of these autochthonous bacterial communities would be explored in the future as depressants for waxy crude oil treatment and for in the oil and gas sector, microbial enhanced oil recovery.