Biodehalogenation, reductive dehalogenation by <i>Methanobacterium Thermoautotrophicum</i>. Comparison with nickel(I)octaethylisobacteriochlorin anion. An F-430 model

Abstract

Abstract The reductive dehalogenation of 1,1,2-tnchloroethane, chloroform, fluorotrichloromethane, carbon tetrachloride, 1,1,1-tnchloroethane, and ethylene dichlonde by Methanobactenum thermoautotrophicum occurs slowly at 60°C in the listed order. Vinyl chloride and chloroacetic acid are inert. The average t1/2 for nearly all substrates is approximately 100 h and varies by a factor of approximately two. In contrast, an active site model for factor F-430, Ni1octaethyhsobactenochlorin, brings about the same transformations with astonishing speed and vast differences in specific rates It is suggested that despite the enormous reducing capacity of this anaerobe, the overall reduction process is limited by permeation factors.