DEGRADATION OF AZO DYES BY CELL-FREE-EXTRACT FROM PSEUDOMONAS-STUTZERI

The degradation of several azo dyes by the cell‐free extract from Pseudomonas stutzeri has been studied. The compounds 2‐carboxy‐4′‐dimethylaminoazobenzene, 4‐carboxy‐4′‐dimethylaminoazobenzene, 2‐carboxy 4′‐die thy lam inoazobenzene, 2‐met hoxycarbonyl‐4′‐dime t h y lam inoazobenzene, 4‐dime t h y lam inoazobenzene sulphonic acid, and 2‐hydroxy‐1 ‐naphthaleneazobenzenesulphonic acid were appreciably degraded by the cell‐ f ree extract. The cell‐ f ree extract was quite specific for 2‐ca rboxy‐4 ′‐diet h y lam inoazo benzen e, 2 met hoxyca rbonyI4′‐dime t h y lam inoazo benzene, and 2‐ca rboxy4′‐dime t h y lam inoazo benzene, which a reequal in their redox potential. Thus, it is suggested that the substrate specificity is characterised by a log Pdependence. The presence of azo reductase in the cell‐free extract was alsoconfirmed by electrophoresis. © 1990 Society of Dyers and Colourists