CRUDE OIL DEGRADATION BY LACCASE PSEUDOMONAS AERUGINOSA NR. 22. A DRIVING FORCE OF BIOREMEDIATION

Pseudomonas aeruginosa NR. 22 (Ps.NR.22) was able to produce bio-surfactant and laccase enzyme to degrade complex hydrocarbon from crude oil. The bio-surfactant was used to increase bioavailability of the hydrophobic crude oil while laccase enzyme acts as an agent to initiate the breaking of hydrocarbon bond. Ps. NR. 22 were fermented for 21 days in nutrient broth containing 2, 5 and 7% (v/v) crude oils. Cell dry weight (CDW) representing cell growth, laccase, biosurfactant production and crude oil residual analysis were recorded throughout the fermentation. The growth was excellent in 5% (v/v) crude oil with 94.1% degradation; when the production of laccase was the lowest. Ideally, as the cells growth, enzyme and biosurfactant production will increase but it was different with Ps.NR.22. This finding suggested the laccase enzyme was not the main tool for the crude oil degradation to take place but the integration of both has made the degradation worked.