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

Abstract

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.