Degradation and Volume-Reduction of Citrus Processing Wastes by Microorganisms

Studies on Microbiological Treatments of Agricultural Processing Wastes Part II

Abstract

Citrus peels supplemented with rice bran and several nutrients were degraded on a laboratory scale by four species of isolated organisms, Hansenula sp. Y-2, Candida sp. Y-11, Byssochlamys sp. M-9 and Aspergillus sp. M-21. The peel mixture was incubated at pH 6.0, 40°C for 5 days. Byssochlamys sp. M-9 was the most effective organism for reducing the weight and volume of the peel, which reducing rate was 54.3% and 29.6%, respectively. During 5 days incubation, the cell masses of Byssochlamys sp. M-9 and Aspergillus sp. M-21 increased during the first 4 days. However, the cell numbers of Hansenula sp. Y-2 and Candida sp. Y-11 increased during the first 2 days and remained relatively constant thereafter. Hesperidin, one of the useful citrus constituents, remained constant throughout the degradation process. Therefore it was suggested that hesperidin wae extracted more effectively from the degraded product than from the untreated peels.