Purification crude extracellular protease of Saccharomycopsis fibuligera strain R64 isolated from Tape' indonesian fermented food

Abstract

The research aims to purify crude extracellular protease produced by Saccharomycopsis fibuligera strain R64 that isolated from tape' Indonesian fermented food. Saccharomycopsis fibuligera strain R64 was tested on Malt Extract Agar (MEA) that added 3% skim milk powder to discover the proteolytic activity. Extracellular protease purified with ammonium sulfate precipitation, dialysis and gel filtration chromatography with Sephadex G-100. Bradford method used to measure protein content, protease activity measured with Walter method and SDS-PAGE used to measure the molecule weight of protease. Results shown that isolated yeasts give 2-5 mm of clear zones on MEA that added with skim milk powder. Precipitations with 45% ammonium sulfate give the best protein content of 5.05 mg/mL and protease activity of 0.051 U/mL. After dialysis the protein content the protease activity were increased to 5.57 mg/mL and 0.0631 U/mL. Moreover, the gel filtration chromatography with sephadex G-100 yields 0.023 U/mL proteolytic activities, 2.1 mg/mL protein contents with 97.4 kD protease molecular weight. © Maxwell Scientific Organization, 2013.