Characterization of an extracellular keratinase of Trichophyton simii and its role in keratin degradation.

The ability of Trichophyton simii HN 50, isolated from the Ghana Bird Sanctuary, Bharatpur, India, to produce extracellular keratinase was studied. Enzyme was produced on a keratin salt broth medium at pH7 and a temperature of 28 +/- 1 degree C. Enzyme secretion was best at 15 days of incubation. Asparagine and keratin were repressive to enzyme yield in comparison to gelatin. No relationship was observed between enzyme release and biomass sugars suppressed keratinase production in descending order as follows: glucose > mannose > maltose > arabinose > fructose. The enzyme showed ability to degrade all of the 3 keratin substrates. Buffalo skin was best degraded in the absence of glucose while chicken feathers were the least degraded in its presence.