Production of Biosurfactant from Hexadecane by Crude Oil Utilizing Pseudomonas aeruginosa Strain K-3 *

Abstract

   Microbial growth on hydrocarbons accompanies the production of surface active agents which help in the dispersion or water immiscible substrate and its transfer into the cells. These biosurfactants having broad range of functional properties have great potential for emulsification, phase separation and viscosity reduction of heavy crude oils suggesting their probable use in enhanced oil recovery. Chemical nature of these biosurfactants varies with the substrate as well as the bacteria applied. Using one of the local isolate Pseudomonas aeruginosa strain K-3, capable of emulsifying crude oil from Khaskheli oil field within 2-3 days, and n-hexadecane as substrate, such surface active compounds were produced. Time course for the growth of this bacterium, pH changes and metabolite production were studied. Extracellular proteins, sugars, intracellular proteins and crude lipids were found to be growth associated. Neutral lipids increased during late growth whereas glycolipids were found to be growth associated. Phospholipids comprised only a minor portion and remained almost constant.