Acid protease synthesis by Mucor pusillus in chemically defined media.

The acid protease synthetized by Mucor pusillus in chemically defined medium displayed a gel filtration pattern and optimal pH similar to that shown by protease isolated from complex medium. Protease synthesis was influenced by the concentration of sulfur in the medium. At sulfur concentrations greater than 10(-4)m, protease synthesis was suppressed, indicating a controlling role of sulfur compounds in the synthesis of extracellular protein. Inorganic phosphate was found to be without negative effect on enzyme synthesis. Growth studies showed that M. pusillus had the capacity to utilize ammonium N, nitrate N, amino N, and urea.