Anaerobic mineralization of stable-isotope-labeled 2-methylnaphthalene

An active sulfate-reducing consortium that degrades 2-methyinaphthalene (2- MNAP) at rates of up to 25 muM day(-1) was established. Degradation was inh ibited in the presence of molybdate and ceased in the absence of sulfate. A s much as 87% of 2-[C-14] MNAP was mineralized to (CO2)-C-14. 2-Naphthoic a cid (2-NA) was detected as a metabolite, and incubation with either deutera ted 2-MNAP or [C-13] bicarbonate indicates that 2-NA is the result of oxida tion of the methyl group. Also detected were carboxylated 2-MNAPs, suggesti ng the presence of an alternative pathway for 2-MNAP degradation.