Biosurfactant production by Bacillus subtilis B20 using date molasses and its possible application in enhanced oil recovery

This study highlights the use of low-cost agro-industrial raw material – date molasses for fermentative production of biosurfactants. Date palm (Phoenix dactylifera L.) is the primary crop in Oman, which shares 82% of all fruit crops production in the country. When date molasses was used as the sole carbon and energy source for biosurfactant production using Bacillus subtilis B20, a product yield of 2.29 ± 0.38 g/l was obtained. The biosurfactant reduced surface tension and interfacial tension from 60 to 25 mN/m to 27 and 5.02 mN/m respectively. It also showed significant stability under a wide range of temperatures, pH and salt concentrations. Additional 9.7% oil was recovered through core-flood studies, accessing the potential of biosurfactant to enhance oil recovery under reservoir conditions. Current studies showed date molasses could be suitable for use in the production of biosurfactant and it has the potential for use in enhancing oil recovery.

► Date molasses was used for biosurfactant production by Bacillus subtilis B20.
► The produced biosurfactant reduced surface tension and interfacial tension.
► The biosurfactant had significant stability under oil reservoir conditions.
► Core-flood studies using biosurfactant showed 9.7% extra residual oil recovery.