A strain Pseudomonas sp.PP1 was isolated from activated sludge and characterized by morphological observation,biochemical and physiological identification as well as 16 S rRNA gene sequence analysis.It was a gram-nega...A strain Pseudomonas sp.PP1 was isolated from activated sludge and characterized by morphological observation,biochemical and physiological identification as well as 16 S rRNA gene sequence analysis.It was a gram-negative,non-motile,rod-shaped with colonies which were white,opaque,small and wrinkled on solid quinoline-MSM.The strain was negative for catalase,gelatin liquefaction,M.R and V.P tests and was unable to reduce / restore nitrate.The 1406 bp 16 S rRNA gene fragment of PP1 was more than 99% identical to the Pseudomonas sp.Biodegradation of quinoline as single substrate was conducted in batch experiments at different temperatures( 15- 40 ℃) and p H values( 5- 10).The results indicate that the optimum conditions for the degradation of quinoline by PP1 were 30 ℃ and p H 7.Pseudomonas sp.PP1 was able to degrade 97.1%,95.4%,94.8%,63.6% and 40.4% quinoline when initial concentrations of quinoline were 50,100,200,300,and 400 mg / L,respectively,and lag phases were prolonged from 2 h to 10 h.The maximum degradation rate( q) was obtained at an initial quinoline concentration( S0) of about 100 mg/L with q of 0.082.The experimentally obtained q values at various initial S0 were fitted by Haldane model,Yano model,Aiba model,Edward model and Webb model,and the results demonstrated that Haldane model gives the best fit for strain PP1 with coefficient of determination,R2= 0.9124 and SDavg= 0.0113208.Five metabolic intermediates were identified by high performance liquid chromatograph( HPLC) and GC / MS.Finally,a possible pathway containing 5,6-dihydroxy-2-oxo-1,2-dihydroquinoline as an intermediate was proposed for the first time.展开更多
Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degra...Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degrading bacterium named CBZ-4 was isolated at a low temperature （10℃） from activated sludge in a municipal wastewater treatment plant. Strain CBZ-4, which can use carbamazepine as its sole source of carbon and energy, was identified as Pseudomonas sp. by the 16S rRNA gene sequence. The composition and percentage of fatty acids, which can reveal the cold-adaptation mechanism of strain CBZ-4, were determined. Strain CBZ-4 can effectively degrade carbamazepine at optimal conditions： pH 7.0, 10℃, 150 r/min rotation speed, and 13% inoculation volume. The average removal rate of carbamazepine was 46.6% after 144 hr of incubation. The biodegradation kinetics of carbamazepine by CBZ-4 was fitted via the Monod model. Vmax and Ks were found to be 0.0094 hr^-1 and 32.5 mg/L, respectively.展开更多
文摘A strain Pseudomonas sp.PP1 was isolated from activated sludge and characterized by morphological observation,biochemical and physiological identification as well as 16 S rRNA gene sequence analysis.It was a gram-negative,non-motile,rod-shaped with colonies which were white,opaque,small and wrinkled on solid quinoline-MSM.The strain was negative for catalase,gelatin liquefaction,M.R and V.P tests and was unable to reduce / restore nitrate.The 1406 bp 16 S rRNA gene fragment of PP1 was more than 99% identical to the Pseudomonas sp.Biodegradation of quinoline as single substrate was conducted in batch experiments at different temperatures( 15- 40 ℃) and p H values( 5- 10).The results indicate that the optimum conditions for the degradation of quinoline by PP1 were 30 ℃ and p H 7.Pseudomonas sp.PP1 was able to degrade 97.1%,95.4%,94.8%,63.6% and 40.4% quinoline when initial concentrations of quinoline were 50,100,200,300,and 400 mg / L,respectively,and lag phases were prolonged from 2 h to 10 h.The maximum degradation rate( q) was obtained at an initial quinoline concentration( S0) of about 100 mg/L with q of 0.082.The experimentally obtained q values at various initial S0 were fitted by Haldane model,Yano model,Aiba model,Edward model and Webb model,and the results demonstrated that Haldane model gives the best fit for strain PP1 with coefficient of determination,R2= 0.9124 and SDavg= 0.0113208.Five metabolic intermediates were identified by high performance liquid chromatograph( HPLC) and GC / MS.Finally,a possible pathway containing 5,6-dihydroxy-2-oxo-1,2-dihydroquinoline as an intermediate was proposed for the first time.
基金supported by the National Creative Research Group from the National Natural Science Foundation of China (No. 51121062)the National Natural Science Foundation of China (No. 51108120, 51178139)+1 种基金the 4th Special Financial Grant from the China Postdoctoral Science Foundation (No. 201104430)the 46th China Postdoctoral Science Foundation (No. 20090460901)
文摘Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degrading bacterium named CBZ-4 was isolated at a low temperature （10℃） from activated sludge in a municipal wastewater treatment plant. Strain CBZ-4, which can use carbamazepine as its sole source of carbon and energy, was identified as Pseudomonas sp. by the 16S rRNA gene sequence. The composition and percentage of fatty acids, which can reveal the cold-adaptation mechanism of strain CBZ-4, were determined. Strain CBZ-4 can effectively degrade carbamazepine at optimal conditions： pH 7.0, 10℃, 150 r/min rotation speed, and 13% inoculation volume. The average removal rate of carbamazepine was 46.6% after 144 hr of incubation. The biodegradation kinetics of carbamazepine by CBZ-4 was fitted via the Monod model. Vmax and Ks were found to be 0.0094 hr^-1 and 32.5 mg/L, respectively.
