Identification of a gene responsible for amido black decolorization isolated from Amycolatopsis orientalis

Investigation into the biodegradative capability of several actinomycetes led to the discovery of many strains possessing an ability to decolorize a variety of azo and triphenylmethane dyes. Of particular interest is an Amycolatopsis sp. isolate which displayed the ability to decolorize the azo dye amido black. Through the screening of a DNA library a 4.5 kbp fragment coding for the potential decolorization gene was identified. The sequencing of this gene fragment led to the prediction of seven open reading frames encoding a polyprenyl synthetase, cupin-2 conserved barrel domain, transcriptional regulator, membrane protein, DNA-damage inducible gene and two hypothetical proteins. A gene coding for a protein consisting of 312 amino acids with 77 % similarity to a conserved hypothetical protein in Amycolatopsis mediterranei was tentatively identified as the enzyme of interest. This is the first report of an amido black biodegrading gene identified in this species.