FIG. 1.

Mass spectra of tetrahydro-2-naphthoic acids (as methyl esters) identified in supernatants of the sulfate-reducing enrichment culture N47 grown on different substrates. (A) Mass spectrum of commercially available 1,2,3,4-tetrahydro-2-naphthoic acid. (B to D) Mass spectra of the tentatively identified 5,6,7,8-tetrahydro-2-naphthoic acid produced in anaerobic degradation experiments with nonlabeled tetralin (B), [1-¹³C]naphthalene (C), and nonlabeled naphthalene in a [¹³C]bicarbonate-buffered medium (D).