Extracellular keratinase from Trichophyton sp. HA-2 isolated from feather dumping soil

A native feather-degrading keratinophilic fungus, Trichophyton sp. HA-2, was isolated from feather dumping soil in India and screened for extracellular keratinase using keratin-agar medium (chicken feathers as substrate). The fungus was grown in mineral salt medium and keratinase production was tested. The highest keratinase production was observed at pH 8.0 and a temperature of 35 °C for a period of 5 weeks. Keratinase secretion was enhanced when cultures were supplemented with a carbon source and keratin source (chicken feathers). This novel keratinase was purified by DEAE-cellulose and sephadex G-100 column chromatography and characterized. The molecular weight of the keratinase was estimated to be 34 kDa by SDS-PAGE. The optimum pH and temperature were determined to be 7.8 and 40 °C, respectively. This enzyme was completely inhibited by phenylmethylsulfonyl fluoride (PMSF), indicating the presence of serine protease.