Utilization of tannery solid waste for protease production by Synergistes sp in solid-state fermentation and partial protease characterization

Synergistes sp. DQ560074 produced a protease in submerged fermentation (SmF) at 400-420 U/mL and in solid-state fermentation (SSF) at 745-755 U/g. The protease, which belongs to the aspartic protease class, was active over a wide range of pH (5-7) and at high temperatures (25-45 degrees C). The protease is stable and active in various polar protic solvents (50% v/v) like ethanol, isopropanol, n-butanol, in polar aprotic solvents (50%v/v) like acetonitrile, and in non-polar solvents (50%v/v) such as ethylacetate and toluene, but not in hydrophilic organic solvents (methyl alcohol and acetone). As far as we know, this is the first contribution to the production of a mesophilic protease with solvent stability in SSF using a proteinaceous solid waste.