Biodegradation of sulfanilic acid by Pseudomonas paucimobilis

An aerobic bacterium, isolated from a contaminated site, was able to degrad e sulfanilic acid (4-aminobenzenesulfonic acid) and was identified as Pseud omonas paucimobilis. The isolate could grow on sulfanilic acid (SA) as its sole carbon and nitrogen source and metabolized the target compound to biom ass. The bioconversion capacity depended on the sulfanilic acid concentrati on; greater than 98% elimination of the hazardous compound was achieved at low (10 mM) sulfanilic acid concentration, and the yield was greater than 7 0% at 50 mM concentration of the contaminant. The maximum conversion rate w as 1.5 mmol sulfanilic acid/h per mg wet cells at 30 degreesC. Ca-alginate- phytagel proved a good matrix for immobilization of P. paucimobilis, with e ssentially unaltered biodegradation activity. Removal of sulfanilic acid fr om contaminated industrial waste water was demonstrated. SDS-PAGE analysis of the crude extract revealed novel proteins appearing upon induction with sulfanilic acid and related compounds, which indicated alternative degradat ion mechanisms involving various inducible enzymes.