Abstract
Engine oil used in automobiles is a threat to soil and water due to recalcitrant properties of its hydrocarbons. It pollute surrounding environment which affect both flora and fauna of earth. Microbes are able to degrade hydrocarbons containing engine oil to utilize as a substrate for their growth. Our results demonstrated that Bacillus velezensis KLP2016 (Gram +ve, endospore forming; Accession number KY214239) cell-free broth recorded an emulsification index (E 24 %) from 52.3% to 65.7% against different organic solvents, such as benzene, pentane, cyclohexane, xylene, n -hexane, toluene and engine oil. The surface tension of the cell-free broth of B. velezensis grown in Luria Bertani broth at 35°C decreased from 55 to 40 mN.m -1 at critical micelle concentration 17.2 µg/mL. The active biosurfactant molecule of cell-free broth of Bacillus velezensis KLP2016 was purified by Dietheylaminoethyl-cellulose and size exclusion chromatography, followed by HPLC (RT=1.130), UV-vis spectrophotometry (210 nm) and thin layer chromatography (R f =0.90). Purified biosurfactant molecular weight was found ~1.0 kDa, on the basis of Electron Spray Ionization-MS. A concentration of 1980×10 -2 parts per million of CO 2 was trapped in a KOH solution after 15 days incubating the bacterium in Luria Bertani broth containing engine oil (1%). Results suggests that bacterium Bacillus velezensis KLP2016 may be a promising solution to the engine oil pollution problem with achieving a bioactive biosurfactant molecule for further eco-friendly application(s).
Molecular analysis of genes involved in chitin degradation from the chitinolytic bacterium Bacillus velezensis
