Genome-wide overview of HP-2023, new insights into its mechanism of dye discoloration.

HP-2023 completely discolorised Reactive Black 5 (200 mg/l) in 24 h. Manganese peroxidase and phenoloxidase, but no laccase activities were detected throughout the incubation. Total aromatic amines in media with Reactive Black 5 decreased 83% after 24 h, supporting an oxidative mechanism of azo dye discoloration. To unravel the genetic basis of these activities, the genome of HP-2023 was sequenced, assembled and annotated de novo. HP-2023 genome comprises 30 MB with a G+C content of 60.75% and 9019 gene models. Thirty-three putative carbohydrate-active enzymes with auxiliary activities, probably involved in lignin degradation and dye discoloration, were identified in the annotated genome, including two laccases, four extracellular fungal heme-peroxidases, nineteen hydrogen peroxide-producing enzymes, and four benzoquinone oxidoreductases. This report will facilitate further studies of textile-dye discoloration with this and closely related strains and poses questions about the ligninolytic potential of HP-2023 and related species.