Isolation of a thermotolerant photosynthetic bacterium, Rhodobacter sphaeroides Strain, NAT, and its capacity for oil and chemical oxygen demand removal at high temperatures.

A thermotolerant photosynthetic bacterium NAT identified as Rhodobacter sphaeroides was isolated. When alginate-immobilized cells of strain NAT were used in high-temperature treatment of artificial sewage wastewater containing oil, the chemical oxygen demand (COD) decreased by 80% and 76% of the oil was removed after 96 h of treatment at 55 degrees C. Lipase activity was observed in the culture.