摘要：Bacterial isolation from the standard activated sludge was performed, their physiological characteristics such as salt and drug resistance were examined, and bacterial flora of the satndard activated sludge was determined. A lot of strains were isolatedfromthestandardactivated sludge under loth saline and fresh water conditions, when a sample was incubated for 3 days at 30°C with polypeptone-meat extract agar plate. It was found that total viable cells were 2.6×107 cells/ml under fresh water condition and 9.7×105 cells/ml under saline condition. The strains from typical colonies were idendified taxonomically, they were Acinetobacter sp., Bacillus sp., Corynebacterium sp., Enterobaceriaceae, Flavobacterium sp . and Moraxella sp . Dominant strains were Acinetobacter sp., Corynebacterium sp . and Enterobacteriaceae and they occupied 37, 25 and 15%, respectively, under fresh water condition. Under saline condition Bacillus sp . was dominant and 78%. PY medium was the best one compared with other media such as PPYE, SS and CF for culture medium. Corynebacterium sp . was able to grow in 2.5M NaCl hypertonic environment, while Bacillus sp . (S2) isolated under salinecondition grew in 3.5M NaCl concentration. The salt resistance in both strains was not specific for Na+, optimal concentration for growth of both strains was 0.5M NaCl, optimal pH range was 7-8, temperature, 30-35°C. All of isolated strains had drug resistance to some antibiotics and salt resistant strains showed also stronger drug resistance in saline environment.
