Abstract
A purple nonsulfur bacteria, strain K-3, was isolated from photodependent denitrifying sludge (PDDS) that was cultivated by fill and draw using methanol as H-donor fbr denitrificalion. It was identified as Rhodobacter sphaeroides by physiological examines and 16S rRNA analysis. With illumination, Strain K-3 has the capability to grow under both aerobic and anaerobic conditions. However, strain K-3 does not have nitrate reduction capability. Additionally, strain K-3 cannot utilize methanol which is the main carbon source of PDDS. These factors suggest that strain K-3 interacts with other bacteria in PDDS in nutrient cycling. While strain K-3 in pure culture can degrade acid azo dyes With hght exposure, it cannot degrade acid azo dyes under dark conditions. Additionally, the presence of enzymes that can degrade dye chemicals under light conditions was discussed.
