EXTRACELLULAR RIBONUCLEASE PRODUCTION BY RHIZOPUS STOLONIFER - INFLUENCE OF METAL-IONS

A strain of Rhizopus stolonifer produced high levels of extracellular ribonuclease (RNase) when grown on YPG (yeast extract, peptone, glucos e) medium. Influence of various medium components on the production of extracellular RNase activity showed that divalent metal ions had a ma rked effect on growth and enzyme production, Maximum enzyme activity ( 3000 U/ml) was obtained in 5 days when the culture was grown in YPG me dium containing Mg2+ (12 mM), Mn2+, and Fe2+ (2 ppm each), Inorganic p hosphate, however, repressed enzyme production, Antibodies raised agai nst the purified extracellular RNase were then used to establish the r elationship between intra- and extracellular enzymes.