Screening for strains of Aspergillus oryzae that degrade carbamide for use in sake brewing

Abstract We screened 65 strains of Aspergillus oryzae for ones that degraded carbamide, Two strains, IFO 5238 and IFO 30113, were selected and used to prepare rice koji . Sake made with the rice koji prepared with these strains had less than half (less than 15 ppm) of the carbamide in sake made with rice koji prepared with commercial spores of A. oryzae .