METABOLISM OF CHLORINATED GUAIACOLS BY A GUAIACOL-DEGRADING ACINETOBACTER-JUNII STRAIN

The metabolism of chlorinated guaiacols by a pure bacterial strain ide ntified by its ability to use guaiacol as the sole carbon and energy s ource was studied. This strain, identified as Acinetobacter junii 5ga, was unable to grow on several chlorinated guaiacols and catechols. Ho wever, strain 5ga grown on guaiacol degraded 4- and 5-chloroguaiacol a nd 4,5-dichloroguaiacol. Under the same conditions, these cells did no t degrade 6-chloroguaiacol, 4,6-dichloroguaiacol, 4,5,6-trichloroguaia col, or tetrachlorognuiacol, suggesting that the substitution at the 6 position in the ring prevents metabolism of the compound. Degradation of 4-chloroguaiacol was dependent on the initial ratio between the ch lorinated compound and viable cells. Transient formation of chlorocate chols resulting from incubation of cells with 4-chloroguaiacol or 4,5- dichloroguaiacol was suggested by UV spectroscopy. Gas chromatography analyses of samples from cultures of strain 5ga grown on guaiacol and incubated with 4- and 4,5-dichloroguaiacol confirmed the presence of 4 -chlorocatechol and 4,5-dichlorocatechol, respectively. The formation of the latter was corroborated by gas chromatography-mass spectrometry . Thus, this strain is able to initiate metabolism of specific chlorin ated guaiacols by O-demethylation. The starting chlorinated guaiacols and their 0-demethylated metabolites inhibited the growth of A.junii 5 ga on guaiacol.