Two forms of glucoamylase were formed in the filtrate of a 6-d culture of Saccharomycopsis fibuligera that had been cultivated under aerobic conditions with an oxygen-transfer rate of 35x10(-7) g mol/ml/min. The glucoamylases, designated as I and II, resembled each other in termes of pH stability, optimum temperature and the effects of various chemicals on enzymatic activity, but the molecular weights (55,000 and 56,000, respectively), isoelectric points (6.5 and 6.1, respectively), thermal stability, and K, values for maltose differed between the two enzymes.