Haloalkane dehalogenases are microbial enzymes that catalyze cleavage of the carbon-halogen bond by a hydrolytic mechanism. Until recently, these enzymes have been isolated only from bacteria living in contaminated environments. In this report we describe cloning of the dehalogenase gene dhmA from Mycobacterium avium subsp. avium N85 isolated from swine mesenteric lymph nodes. The dhmA gene has...

Microbial metabolism is responsible for the removal of persistent organic pollutants including PCBs from the environment. Anaerobic dehalogenation of highly chlorinated congeners in aquatic sediments is an important process, and recent evidence has indicated that Dehalococcoides and related organisms are predominantly responsible for this process. Such anaerobic dehalogenation generates lower c...

Substituent effects have been used as a means of probing the nature of the transition state for C–I bond cleavage on the Pd(111) surface. The barriers to C–I cleavage (1EC–I) have been measured in a set of 10 different alkyl and fluoroalkyl iodides (CH3I, CF3I, CH3CH2I, CF3CH2I, CF2HCF2I, CH3CH2CH2I, CF3CH2CH2I, CF3CF2CH2I, (CH3)2CHI, and (CH3)3CI ) on Pd(111). These measurements were performed...

The capacity of metal-containing porphyrinoids to mediate reductive dehalogenation is implemented in cobamide-containing reductive dehalogenases (RDases), which serve as terminal reductases in organohalide-respiring microbes. RDases allow for the exploitation of halogenated compounds as electron acceptors. Their reaction mechanism is under debate. Here we report on substrate-enzyme interactions...

[This corrects the article on p. 3270 in vol. 59.].

Alkyl bromides and chlorides can be reduced to the corresponding hydrocarbons utilizing zinc in the presence of an amine additive. The process takes place in water at ambient temperatures, enabled by a commercially available designer surfactant. The reaction medium can be readily recycled, and the amount of organic solvent invested for product isolation is minimal, leading to very low E Factors.

Dehalogenases play key roles in the detoxification of halogenated aromatics. Interestingly, only one hydrolytic dehalogenase for halogenated aromatics, 4-chlorobenzoyl-coenzyme A (CoA) dehalogenase, has been reported. Here, we characterize another novel hydrolytic dehalogenase for a halogenated aromatic compound from the 2,4,5,6-tetrachloroisophthalonitrile (chlorothalonil)-degrading strain of ...