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Abstract

Malbranchea gypsea IMI 338,168 isolated from the soils of Keoladeo National Park, Bharatpur was studied for its ability to produce exocellular proteases on glucose-gelatin medium at pH 7; 28 degrees C. The fungus was observed to be a potent producer of such enzymes. Protease production was optimal at 15 days of incubation. Asparagine was repressive to protease expression. No relationship existed between the amount of enzyme production and increase in biomass. Exogenous sugars suppressed enzyme production in descending order as follows: glucose > mannose > maltose > arabinose > fructose. The enzymes expressed showed the ability to degrade three keratinous substrates tested. Buffalo skin was the most actively degraded substrate when exogenous glucose was present, and was also the most resistant to degradation in the absence of glucose. The rate of keratin deterioration was independent of enzyme activity. Production of protease enzymes especially keratinases is ecologically important in a place like a National Park because such enzymes degrade keratinous detritus derived from mammals and birds. Accumulation of such materials can be a cause of pollution and can provide a breeding spot for various types of pathogens.

Purification and Characterization of a Keratinase from a Feather-Degrading Fungus,Aspergillus flavusStrain K-03

“…In addition, the biomass increased steadily with incubation time. Similar production kinetics of keratinase has been reported for fungi such as Endothia parastica (Melzer and Boland, 1999), Trichophyton simii (Singh, 1997), Malbranchea gypsea (Singh, 1998), and Trichophyton vanbreuseghemii (Moallaei et al, 2006). In A. fumigatus (Do et al, 2004) and A. oryzae (Jousson et al, 2004), the rate of keratinase production reached a maximum concentration after 21 days of incubation and the concentration of extracellular keratinase produced by Lysobacter NCIMB 9497 (Allpress et al, 2002) was maximal after 29 days of growth.…”

Influence of the carbon and nitrogen sources on keratinase production by Myrothecium verrucaria in submerged and solid state cultures

“…Keratinase has been produced under submerged shaking conditions, except for a few thermophilic bacteria [11,25,31] and fungi [17,35] for which static submerged fermentation has been reported. The use of solid state fermentation is much less common [7,9].…”