B. subtilis used in the present study could utilize I. cylindrica
(an unutilized grass) and potato peel (kitchen waste) as
low-cost waste residues for alkaline protease production under
thermophilic SSF condition. This method of protease production
does not require any additional supplementation of co-carbon
and co-nitrogen sources thus further reducing the production
cost. The protease produced by B. subtilis in accordance with
the present method, is free of undesirable flavor that is advantageous
for its use in food and pharmaceutical industries. The
thermal resistance, ability to function in a broad range of temperature
particularly at room temperature, extreme alkaline pH
stability and compatibility with tested commercial laundry detergents
may lead to conclude that future application of B. subtilis
DM-04 protease in laundry detergents formulations and in food
and pharmaceutical industries is highly promising.