The characteristics and mechanisms of pyridine biodegradation by Streptomyces sp.

A novel Streptomyces sp. HJ02 can grow using pyridine as only carbon resource and has strong ability of pyridine degradation. The effect of pH, temperature, concentration of pyridine and sucrose addition on biodegradative capacity of Streptomyces sp. HJ02 was examined. The main metabolism pathways and mechanism of pyridine degradation by HJ02 strain were described. The Streptomyces sp. HJ02 degraded 2000 mg/l of pyridine nearly within 8 days. The glucose added in culture inhibited on activity of both SSD and amidase. These two enzymes can act and retain its catalytic ability over wide ranges of temperature and pH. The SSD had a higher activity in alkalescence condition from pH 7.0 to pH 10.0 and was more stable at elevated temperatures from 25 degrees C to 40 degrees C. This strain exhibited both succinate semialdehyde dehydrogenase (EC 1.2.1.24) (SSD) and amidase in free cell extracts obtained from cells grown exclusively on pyridine or with sucrose added, suggesting that the metabolism of pyridine was ripped between C-2 and C-3, and pyridine was hydrolyzed to succinate semialdehyde and formamide.