Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
Appl Environ Microbiol. 1993 Jul;59(7):2041-8. doi: 10.1128/aem.59.7.2041-2048.1993.
With the pure bacterial cultures Ancylobacter aquaticus AD20 and AD25, Xanthobacter autotrophicus GJ10, and Pseudomonas sp. strain AD1, Monod kinetics was observed during growth in chemostat cultures on 1,2-dichloroethane (AD20, AD25, and GJ10), 2-chloroethanol (AD20 and GJ10), and 1,3-dichloro-2-propanol (AD1). Both the Michaelis-Menten constants (K(m)) of the first catabolic (dehalogenating) enzyme and the Monod half-saturation constants (K(s)) followed the order 2-chloroethanol, 1,3-dichloro-2-propanol, epichlorohydrin, and 1,2-dichloroethane. The K(s) values of strains GJ10, AD20, and AD25 for 1,2-dichloroethane were 260, 222, and 24 muM, respectively. The low K(s) value of strain AD25 was correlated with a higher haloalkane dehalogenase content of this bacterium. The growth rates of strains AD20 and GJ10 in continuous cultures on 1,2-dichloroethane were higher than the rates predicted from the kinetics of the haloalkane dehalogenase and the concentration of the enzyme in the cells. The results indicate that the efficiency of chlorinated compound removal is indeed influenced by the kinetic properties and cellular content of the first catabolic enzyme. The cell envelope did not seem to act as a barrier for permeation of 1,2-dichloroethane.
使用纯细菌培养物 Ancylobacter aquaticus AD20 和 AD25、Xanthobacter autotrophicus GJ10 和 Pseudomonas sp. strain AD1，在恒化器培养物中观察到了 1,2-二氯乙烷 (AD20、AD25 和 GJ10)、2-氯乙醇 (AD20 和 GJ10) 和 1,3-二氯-2-丙醇 (AD1) 上生长的 Monod 动力学。第一个分解代谢（脱卤）酶的米氏常数 (K(m)) 和 Monod 半饱和常数 (K(s)) 均遵循 2-氯乙醇、1,3-二氯-2-丙醇、表氯醇和 1,2-二氯乙烷的顺序。菌株 GJ10、AD20 和 AD25 对 1,2-二氯乙烷的 K(s) 值分别为 260、222 和 24 μM。菌株 AD25 的低 K(s) 值与该细菌更高的卤代烷脱卤酶含量有关。在连续培养物中，菌株 AD20 和 GJ10 在 1,2-二氯乙烷上的生长速率高于从卤代烷脱卤酶动力学和细胞中酶浓度预测的速率。结果表明，氯化化合物去除的效率确实受到第一分解代谢酶的动力学特性和细胞含量的影响。细胞膜似乎并未对 1,2-二氯乙烷的渗透起到屏障作用。
