Limonoid is a bitter principle of Citrus fruit. As the taste of this principle is excessively and disagreeably bitter, the practial method for reducing such taste has been earnestly desired. But good meghod for the purpose was not discovered. The most suitable procedure should bu the enzymatic decomposition, there fore, a program was umdertaken to screen a large number of microorganisms for the capacity to produce enzyme be capable of decomposition of limonoid. The present paper deals with the culture, extraction, and properties of enzymes which were obtained from some strains of Aspoergillus and Penicillium sp.. ....