Our investigations, therefore, were directed toward
examining the biodegradation and decolorization of two
azo dyes, namely Congo Red (CR, Direct Red 28) and
Direct Black 38 (DB 38), by two different facultative
bacteria (E. coli and Pseudomonas sp.) under anaerobic,
aerobic and microaerophilic conditions. The biomass
growths of the aforementioned bacteria, COD, colour,
pH and volatile fatty acids (VFA) variations were
investigated during 4 and 9 days batch incubation
periods. Furthermore, aromatic amines as product of
azo cleavage and recovered amines were monitored as
benzidine equivalent under anaerobic, aerobic and
microaerophilic conditions.