parviz darvishi - school of chemical and petroleum engineering
dariush mowla - environmental research center inoil
shahab ayatollahi - EOR research cente shiraz university
ali niazi - institute of biotechnology shiraz university

The potential biodegradation of heavy crude oil from waste water was assessed based on the development of a fermentative process with a new strain of enterobacter cloacea ERCPPI-1 which was isolated from heavey crude oil in south of iran , when cultured in a basal mineral medium using heavy crude oil as the sole carbon source. the effects of heavy crude oil concentration , temperature , pressure, ph and dalinity on the growth rate of ERCPPI-1 in the presence of heavy crude oil as the sole carbon source were investigated. the results showed that ERCPPI-1 has a good potential for biodegradation of heavy crude oil in the concentration ranges of 0.25 % to 10% , temperatures up to 70 C , pressures up to 6000 pisa, pH ranges of 4 to 10 , and salinities up to 15% . however as the concentration of heavy crude oil is increased from 0.25% to 10% , the percentage of degradation by the strain is decreased from 76.3% to 19.1% . temperature of 40C , pressure of 6000 psia and pH of 7.0 were found to be the optimum conditions for maximum biodegradation rate . the experiments also showed that the strain ERCPPI-1 was able to produce a type of biosurfactant using heavy crude oil as the sole carbon source , with high oil spreading and emulsification properties.

enterobacter cloacea, heavy crude oil , biodegradation, biosurfactant , ex-situ,in-situ