Initial steps in the degradation of benzene sulfonic acid, 4-toluene sulfonic acids, and orthanilic acid in Alcaligenes sp. strain O-1.
Alcaligenes sp. strain O-1 grew with benzene sulfonate (BS) as sole carbon source for growth with either NH4+ or NH4+ plus orthanilate (2-aminobenzene sulfonate, OS) as the source(s) of nitrogen. The intracellular desulfonative enzyme did not degrade 3- or 4-aminobenzene sulfonates in the medium, although the enzyme in cell extracts degraded these compounds. We deduce the presence of a selective permeability barrier to sulfonates and conclude that the first step in sulfonate metabolism is transport into the cell. Cell-free desulfonation of BS in standard reaction mixtures required 2 mol of O2 per mol. One mol of O2 was required for a catechol 2,3-dioxygenase. When meta ring cleavage was inhibited with 3-chlorocatechol in desalted extracts, about 1 mol each of O2 and of NAD(P)H per mol of BS were required for the reaction, and SO3(2-) and catechol were recovered in high yield. Catechol was shown to be formed by dioxygenation in an experiment involving 18O2. 4-Toluene sulfonate was subject to NAD(P)H-dependent dioxygenation to yield SO3(2-) and 4-methylcatechol, which was subject to meta cleavage. OS also required 2 mol of O2 per mol and NAD(P)H for degradation, and SO3(2-) and NH4+ were recovered quantitatively. Inhibition of ring cleavage with 3-chlorocatechol reduced the oxygen requirement to 1 mol per mol of OS SO3(2-) (1 mol) and an unidentified organic intermediate, but no NH4+, were observed.
Microbiology Institute, Swiss Federal Institute of Technology, ETH-Zentrum, CH-8092 Zürich.
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Thurnheer
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Zürrer
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Höglinger
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Leisinger
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Cook
D000421:Alcaligenes / Q000378:metabolism*; D001557:Benzenesulfonates / Q000378:metabolism; D001673:Biodegradation, Environmental; D001693:Biological Transport, Active; D002396:Catechols / Q000378:metabolism; D002463:Cell Membrane Permeability; D013425:Sulfanilic Acids / Q000378:metabolism; D013451:Sulfonic Acids / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D014105:Tosyl Compounds / Q000378:metabolism
D001557:Benzenesulfonates; D002396:Catechols; D013425:Sulfanilic Acids; D013451:Sulfonic Acids; D014105:Tosyl Compounds; C032365:benzenesulfonic acid; C034221:catechol; C029501:4-toluenesulfonic acid; C100048:2-sulfanilic acid