azo dye reducing enzymes were found to degrade azo dyes
under fully aerobic condition [17,18]. The initial step in the
biodegradation of azo compounds is a reductive cleavage of
the azo group. This reaction is catalyzed by various biological
systems under anaerobic conditions and leads to accumulation
of aromatic amines. The reduction of the azo bond can
be mediated by facultative as well as obligate anaerobes or
under microaerophilic conditions [5,19]. Molecular oxygen
inhibits the azoreductase enzyme. Blumel et al. [20] reported
that have studied Hydrogenophaga palleronii S1 seems to
have aerobic azoreductase activity. Aerobic processes could
not decolorize the wastewater since the compounds are often
recalcitrant. However, most of the studies on aerobic decolorization
of dyes are restricted to single dye degradation
[21]. Caughlin et al. [14] have obtained the bacterial strain
TB × 65 with the unusual ability to reduce the azo bond
of several azo dyes aerobically and use some of there dyes
as growth substrates. Apparently, there is still a need to develop
novel biological decolorization processes leading to
more effective clean up of azo dyes from was