Valorization of oily sludge waste using biosurfactant-producing bacteria

This study demonstrates a methodology for the valorization of the oily sludge that allows the recovery of oil fractions by the action of microbes producing surface-active metabolites. Two bacterial isolates were used in the study that were producing different biosurfactants, identified via FTIR analysis as well as through genomic mapping of the biosurfactant pathways using RAST, ANTISMASH 7.0, STRING databases.Serratia spp. AKBS12, produced a mono-rhamnolipid, whileAcinetobacter spp. AKBS16, produced emulsan. Although recovery efficiency of both biosurfactants was similar, the recovery profile with respect to the class of hydrocarbons differed. The rhamnolipid produced bySerratia spp. AKBS12 extracted mono-chained paraffins and linear alkanes, while emulsan, produced byAcinetobacter spp. AKBS16 could extract heavier paraffins. The extraction procedure is simple and involves mixing the biosurfactant with oily sludge at a temperature of 30 °C with an incubation of 9 days. Sulphuric acid precipitation releases the oil trapped in the oily sludge. The study is the first step in developing user-friendly, innovative technologies that can be linked to the concept of a circular economy.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research