Earth Science Frontiers ›› 2008, Vol. 15 ›› Issue (6): 169-176.
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School of Water Resources and Environment, China University of Geosciences(Beijing), Beijing 100083, China
Online:
Published:
Abstract:
The effects of initial substrate concentration, temperature and pH on the phenanthrene biodegradation characteristics and enzymatic reaction kinetics were studied by using a strain of gramnegative bacteria J1 that is isolated and purified from the active sludge. The sludge collected from Membrane Bioreactor was cultured and acclimated with phenanthrene. The bacteria cells, in the shape of a short rod, are about 25 μm long and 13 μm wide. The phenanthrene in the aqueous solution was completely degraded in 48 h, however, the biodegradation time prolonged when the initial concentration increased. The temperature had significant effect on the phenanthrene biodegradation by strain J1. The optimum temperature of the biodegradation was 28 ℃. With the same initial concentration of phenanthrene, the biodegradability of phenanthrene was found to be decreased with increasing or decreasing the temperature. 100% of the phenanthrene was degraded in 48 h for the concentration of 115 mg·L-1 when the temperature was 28 ℃. However, less than 37% of phenanthrene could be degraded, if the temperature was decreased to 10 ℃. The biodegradation ability of the strain J1 had a certain adaptability with the variety of pH between 6084 and the optimum pH was 72. The experimental outcomes could be fit well with the firstorder biodegradation kinetics model. The high substrate concentration inhibited the enzymatic reaction. The maximum rate constant vm, Michaelis constant Km, substrate inhibition constant kS, and the optimum substrate concentration [S]opt of the enzymatic reaction were 117 mg·L-1·h-1, 6170 mg·L-1, 4960 mg·L-1, and 5532 mg·L-1, respectively.
Key words: phenanthrene; biodegradation characteristics; enzymatic reaction; Michaelis constant; substrate inhibition; kinetics
phenanthrene; biodegradation characteristics; enzymatic reaction; Michaelis constant; substrate inhibition; kinetics
CLC Number:
X703.1
XI Hong-Bei YANG Qi CHANG Hai-Chao HAO Chun-Bo. Biodegradation characteristics and enzymatic reaction kinetics of phenanthrenedegrading bacteria.[J]. Earth Science Frontiers, 2008, 15(6): 169-176.
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