MINERALIZATION AND DESULFONATION OF 3-NITROBENZENESULFONIC ACID BY ALCALIGENES SP GA-1

A 3-nitrobenzenesulfonic acid (3-NBS)-degrading bacterium was isolated from a batch enrichment culture containing 3-NBS and yeast extract, a nd identified as an Alcaligenes sp. In a batch degradation test, the i solate, named GA-1, utilized 3-NBS as a growth substrate with stoichio metric accumulation of sulfate ions, and consumed most of the dissolve d organic carbon (DOC) which originated from 3-NBS in the culture. A t race amount of sulfite ions was also detected on an agar test plate of mineral salts (MS) medium containing 3-NBS and Ellman's reagent (5,5' -dithiobis[2-nitrobenzoic acid]), which reacts sensitively with free s ulfite ions to develop a yellow coloration. These results indicate tha t 3-NBS was effectively desulfonated and mineralized by strain GA-1 wi th the release first of sulfite ions, which were then oxidized immedia tely to sulfate ions.