Fagade, Obasola E, Okolie, Blessing I., Balogun, Saka
Nigerian Journal of Micro biology, 2009, Vol. 23(1);1911 -1917
Abstract
Bacillus isolates from soil samples contaminated with heavy oil in Ibadan and previously studied oil contaminated sites were screened for biosurfactant production using haemolytic test and rapid glass
sliding screening test techniques. The optimal conditions for biosurfactant production using different carbon and nitrogen sources were investigated. About twenty -four Bacillus isolates were used for this study, and the isolates utilized crude oil, diesel oil, palm oil and glucose as carbon sources while ammonium chloride, sodium nitrate and peptone were utilized as nitrogen sources for biosurfactant production. Biosurfactant production in the isolates was highest when crude oil was used as
carbon/energy source and ammonium chloride as nitrogen source (E24 96.2%) in B. licheniformis (BS 102) and least in diesel as carbon source and sodium nitrate as nitrogen source (E24 2.9%) in B. subtilis (BS58). Diesel is the best hydrocarbon substrate among those tested for emulsification activity, it had emulsification index (E24) of 96.2%, kerosene had E24 56%, while crude oil had nil. Among the carbon/energy sources tested, crude oil was best, followed by palm oil while diesel oil was the poorest and among the nitrogen sources, ammonium chloride was the best nitrogen source, followed by peptone while sodium nitrate was the poorest.