Bacillus mojavensis JF-2 (JF-2) grew and synthesized biosurfactant under anaerobic conditions in sand-pack columns in the presence of other competing organisms. The surface tension of the column effluent was 38 mN/m when the columns were injected with an inoculum size of 10 to the 8th power cells/ml. A slightly higher surface tension (44 mN/m) was obtained when the inoculum size was 10 to the 4th power cells/ml. Growth with glucose gave the fastest growth rate for Bacillus mojavensis JF-2 (JF-2) and monosaccharides in general were the preferred carbon source. The fastest growth rate occurred with a glucose concentration of 77 mM. Fructose appeared to produce the highest growth yield. The sample preparation steps used for high performance liquid chromatography (HPLC) analysis resulted in a biosurfactant recovery (from culture supernatant) of about 70%. The presence of Proteose peptone no. 2 (PP2) in the medium led to increased biosurfactant production under anaerobic conditions. The biosurfactant was present after extended incubation suggesting that production of biosurfactant was not confined to the exponential phase of growth under anaerobic conditions. Although it is not known exactly when maximum production of biosurfactant occurred, the data suggests that biosurfactant production occurred during stationary phase since maximal growth was reached by 48 hrs.
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