Studies On Screenning Of Streptomyces Strain And Its Tretment For Heterocyclic Compounds In Water

Nitrogenous Heterocyclic Compounds are widely used as solvents and intermediate in the production of agricultural chemicals, drugs, dyestuffs and paints, rubber products, polycarbonate resins and texitile water-repellents. The N-heterocyclic compounds are of major concern as environmental pollutants due to their recalcitrant, persistent, and toxic. Otherwise, the heterocyclic compounds were reported to be carcinogenic and mutagenic and do huge harm to the environment and human health. The research on the effective treatment technical of heterocyclic compounds organic wastewater is focused more and more and become a challenge in the environmental protection domain.In this research, the HJ02 strain was isolated and appraised, which had remarkable effects of the degradation to pyridine and indole. The HJ02 strain culture condition, the biodegradation effects, the degradation kinetics, and so on were studied. The heterocyclic compounds degradation mechanism and the security of degradation products were discussed.The main conclusions of the research are as follows:1. A novel actinomycete pyridine-degrading strain called HJ02 strain was isolated from activated sludge of coke-oven wastewater treatment plant. Morphology, cultural characteristic, biochemical characterization and the mensuration of cell wall structure studies strongly suggested that this strain belongs to Streptomyces sp.2. The feasible pH range, the temperature and the surge rate for growth of HJ02 strain is between 3.0 and 4.0, 25℃and 200 rpm, respectively. The feasible carbon source and nitrogen source is glycerol and NH₄Cl, respectively.3. Streptomyces sp.HJ02 could grow using pyridine as sole carbon and nitrogen source and has rather strong ability to endure pyridine. Under the conditions of 30℃, pyridine removal rate of 2000 mg·L^-1 can reach 97.0% in 7 days. The pyridine-degradation kinetics of HJ02 strain was fitted to the one-order law model: -dC/dt = K. The K value of 2000 mg·L^-1 pyridine-biodegradation reaches the highest value which was 0.6891 d^-1, because high pyridine concentration inhibited the degradation of pyridine.4. This strain can exhibited activity of both succinate semialdehyde dehydrogenase and amidase in free cell extracts. The activities of succinate semialdehyde dehydrogenase and amidase reach the highest value which were 0.45 U·mg^-1 and 0.69 U·mg^-1 respectively when use pyridine as single carbon resource. The succinate semialdehyde dehydrogenase activity was optimal at pH8, 30℃, while the optimal condition of amidase is pH7.0, 35℃.5. Streptomyces sp.HJ02 could grow using indole as sole carbon and nitrogen source and has rather strong ability to endure 300 mg·L^-1 indole, whose removal rate can reach 97.4% in 6 days under the conditions of 30℃, pH7.0, 100 rpm. The indole-degradatinon kinetics of HJ02 strain was fitted to the logistic law model: dS/dt=-μ₄SX/(S+K_S+S²/K_r)Y_X/S). At 50 mg·L^-1 of the indole:μ_A=1.627d^-1, K_S =12.5 mg·L^-1, Ki=43mg·L^-1.6. The UV spectrum and GC chromatogram showed that the ring of pyridine and indole was broke down by HJ02 strain.