The production and purification of alkaline protease from local strain of the
Egyptian soil fungus trichoderrna viridi was investigated. The enzyme which hydrolyze
casein was produced at high level when fungus was grown for 6 days on a medium
supplemented with 1.5% wlv starch as a carbon source, soybean flower (0.14% N₂)
as a nitrogen source and initial pH 6.5 at 28·C. A 30.06 fold purified enzyme was
obtained by acetone precipitation flowed by gel filtration using sephadix G-100.
Protease was found to be highly active at pH 8.5 and 55·C, and stable up to 60 min at
pH 7 and 50·C. Mutations Zn²+, Mn2+ and Cu²+ activated the enzyme, whereas C0²+,
Fe²+ and k+ inhibited the enzyme activity. The activity of enzyme was found to be
stable in liquid detergent (locally producer).