Efficient screening of petroleum-degrading bacteria under high salt acclimation

Four strains of bacteria that can grow with petroleum hydrocarbon as sole source of carbon and energy, were isolated from petroleum-contaminated soils in Shengli oil field. Petroleum-hydrocarbon degradation can rate up to 78.6% after the strain has grown on inorganic salt medium with 500mg/L petroleum-hydrocarbon concentration at 30°C for 5d(NaCl 1%). Meanwhile acclimating the four bacteria in high salt condition to make them reach a high degradation in inorganic salt medium with 500mg/L petroleum-hydrocarbon and 100g/L NaCl. The strain Y-1 which was identified as Staphylococcus haemolyticus can reach the highest rate of degradation 54.4% with 100g/L NaCl. The microorganisms which can survive in petroleum hydrocarbon waste water with high salt have great potential in treating oilfield wastewater.