Screening of biosurfactant-producing microorganisms for application in oil industries

Biosurfactants are surface-active agents produced by different microorganisms like bacteria, yeasts, and fungi.Biosurfactants have advantages over chemical surfactants such as; biocompatibility, less toxicity, high variety, high efficiency in uncommon temperatures, salinity and pHs, they can be synthesized from cost-effective and renewable sources and they can also be produced through fermentation. One of the main applications of biosurfactants is their usage in microbial enhanced oil recovery (MEOR) processes. The aim of this study is a separation of microorganisms with the ability to produce biosurfactants with the applications in oil processes. Local samples were gathered from different spots in Tabriz refinery like clarifier, oil contaminated soils, oil sludge, and kerosene. Separation of bacteria was carried out in a growth medium of mineral salt (MSM) with crude oil as the only carbon source and heating time of 47 c.Molecular characterization of the chosen bacterium was done via 16S rRNA. Biosurfactant production by separated bacteria was investigated using three semi-quantitative methods of hemolysis, drop collapse and oil spread technique. A quantitative study of production in the chosen isolate was carried out using the method of dry weight measurement. 20 isolates were separated and purified from the samples. The OT9 isolate was chosen as the proper isolate based on the results of tests mentioned above and was characterized as the Bacillus licheniformis. The value weight for the produced biosurfactant in OT9 isolate was 2.2 mg⁄ml .

Keywords:

Biosurfactant , Bacillus licheniformis , Microbial Enhanced Oil Recovery