Blockage of methanogenesis in marine sediments by the nitrification inhibitor 2-chloro-6-(trichloromethyl) pyridine (Nitrapyrin or N-Serve)

Nitrapyrin or N-Serve 2-chloro-6-(trichloromethyl)pyridine] blocked methanogenesis associated with slurries of marine sediments. Both nitrapyrin and chloroform, an established inhibitor of methanogenic bacteria, were effective at micromolar concentrations. Chemical hydrolysis of nitrapyrin resulted in the release of three molar equivalents of chloride ions and the loss of its ability to inhibit methane production. Thus, the potency of nitrapyrin in blocking methanogenesis seemed to depend upon its trichloromethyl moiety; this conclusion was supported in experiments with other substituted pyridine compounds.