Nghiên cứu sản xuất chế phẩm Aspergillus oryzae KZ3 kết hợp Streptomyces rochei HĐM03 có hoạt độ Cellulase cao và thử nghiệm tách nhớt hạt cà phê

Abstract

This study aimed to investigate some factors (inoculum ratio, medium composition, initial moisture content of the substrate, temperature, incubation time and drying temperature of the preparation) effects on the production process of Aspergillus oryzae KZ3 combined with Streptomyces rochei HDM03 preparation possessing high cellulase production ability on semi-solid medium and to apply the application of this preparation in the treatment of viscous separation of coffee beans at laboratory and pilot scale. The cell density of the preparation was determined by colony counting on Gause I and PDA medium. Cellulase activity was determined based on a colorimetric method with DNS reagents. The results showed that, on semi-solid medium consisting of 70% rice bran and 30% rice husk, 55% initial moisture content, starter culture including 0.3% of A. oryzae KZ3 and 6% of S. rochei HDM03, 4 days of incubation at 30^oC, cellulase activity and cell density were highest, reaching 971.038 UI/g dry matter and 8.463 logcell/g, respectively. Adding preparation of A. oryzae KZ3 and S. rochei HDM03 at the rate of 6% into coffee bean processing procedure in the laboratory and pilot scales, the viscous separation efficiency of coffee beans was 99.29% and 98.83%, respectively.