THE COMPARISON STUDY OF ACTIVITIES OF ENDOGLUCANASE AND ?- GLUCOSIDASE FROM BACILLUS AMYLOLIQUEFACIENS EXPRESSED IN FUSION AND CO-EXPRESSION FOR SUGARCANE BAGASSE DEGRADATION

• Main Author: Alfi, Almasul
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/34454
• Institution: Institut Teknologi Bandung

Sugarcane bagasse reached to 35–40% of the mass total of sugarcane is solid waste obtained from the sugarcane mill. Sugarcane bagasse hydrolyzed by endoglucanase (EglII) and ?- glucosidase (BglZ) can produce glucose. Previous study showed that the mixture of EglII and BglZ has been expressed in Bacillus megaterium MS941 in the form of either fusion protein (Fusi-EglII-BglZ) or co-expression protein (Rbs-EglII-BglZ). The objective of the present study was to compare the activities between Fusi-EglII-BglZ and Rbs-EglII-BglZ with the respect of sugarcane bagasse degradation. The research steps included the treatment of sugarcane bagasse (homogenized, autoclaved and delignification by acid), preparation of the enzymes, and hydrolysis reaction. The glucose concentration produced by the hydrolysis was determined by the method of dinitrocalicylic acid and the residues of sugarcane bagasse were characterized by the method of infrared spectroscopy as well as X-ray diffraction. The duration of the enzymes to degrade sugarcane bagasse was also determined. The result showed that the delignificated sugarcane bagasse was obtained from the acid treatment, and was identified by the decrease in intensity at wave number 1.510 cm–1. Based on the X-ray diffraction analysis, the cellulose crystalline of sugarcane bagasse remained unchanging. Using the same protein concentration, the activities of both Fusi-EglII-BglZ and Rbs-EglII- BglZ for hydrolyzing of treated sugarcane were higher than for raw sugarcane bagasse degradation, indicating the treated sugarcane bagasse was easily digested. For hydrolyzing 60 mg sugarcane bagasse with the same protein concentration, Rbs-EglII-BglZ worked 2.5- fold faster than Fusi-EglII-BglZ with the maximum amount of reducing sugar released was 3,431 and 3,948 ?mol, respectively. The specific activity of Rbs-EglII-BglZ to the treated sugarcane bagasse (206,255 U/mg) was 1.7-fold higher than that of Fusi-EglII-BglZ (120,865 U/mg). Based on X-ray diffraction, the structure of cellulose crystalline of degraded sugarcane bagasse remained constant, indicating the enzym was fully reacted to substrate.