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ENZYMATIC SACCHARIFICATION OF HEMI-CELLULOSES IN THE BIOCONVERSION OF BIOMASS.

Objective

THE PURPOSE OF THIS PROJECT IS TO OPTIMIZE THE ENZYMATIC SACCHARIFICATION OF HEMI-CELLULOSES IN BIOMASS.

HEMICELLULOSES RANK NEXT TO CELLULOSE AS THE SECOND MOST ABUNDANT RENEWABLE POLYSACCHARIDE IN NATURE. FOR THE ECONOMICS OF THE BIOCONVERSION OF BIOMASS TO FUELS AND CHEMICALS IT IS IMPORTANT THAT HEMICELLULOSES (XYLANS, ARABINANS, GALACTANS, GLUCANS AND MANNANS) ARE ALSO FULLY UTILIZED. OUR KNOWLEDGE OF THEIR COMPLETE DEGRADATION TO MONOMERS BY MULTIPLE ENZYME COMPLEXES IS STILL LIMITED. MORE INSIGHT INTO THESE MATTERS IS NECESSARY TO DIRECT GENETIC MANIPULATION OF MICRO-ORGANISMS FOR PRODUCTION OF RELEVANT ENZYMES AND TO OPTIMIZE COMPOSITION OF ENZYME FORMULATIONS. THIS RESEARCH IS AIMED TOWARDS SCREENING OF TECHNICAL AND EXPERIMENTAL ENZYME PREPARATIONS FOR THEIR POTENTIAL TO DEGRADE HEMI-CELLULOSIC MATERIAL: IDENTIFICATION, ISOLATION AND PURIFICATION OF RELEVANT ENZYMES, ESTABLISHING THEIR MODE OF ACTION, SYNERGISTIC EFFECTS AND COMPOSITION OF THE MOST EFFECTIVE MULITPLE ENZYME COMPLEXES AND TOWARDS ESTABLISHING EFFECTS OF PRETREATMENTS AND POSSIBILITIES FOR RE-USE OF ENZYMES IN MEMBRANE REACTORS.
IN THE PERIOD UNDER REVIEW FUNGAL TECHNICAL ENZYME PREPARATIONS WERE SCREENED FOR XYLANOLYTIC, ARABINANOLYTIC AND GALACTANOLYTIC ENZYME ACTIVITIES. FROM AN EXPERIMENTAL PREPARATION DERIVED FROM ASPERGILLUS NIGER, WHICH WAS FOUND TO BE VERY POWERFUL IN ARABINAN AND GALACTAN DEGRADATION, THREE ARABINAN AND THREE GALACTAN DEGRADING ENZYMES WERE ISOLATED AND PURIFIED TO HOMOGENEITY USING AMONGST OTHERS FPLC. THEIR GENERAL PROPERTIES (ISOELECTRIC POINT, MOLECULAR WEIGHT, PH OPTIMUM, TEMPERATURE OPTIMUM, KM, VMAX, SUBSTRATE SPECIFICITY AND MODE OF ACTION) AS WELL AS THEIR SYNERGISTIC EFFECTS ARE BEING STUDIED. STRONG SYNERGISTIC EFFECTS BETWEEN ARABINAN-DEGRADING ENZYMES ARE FOUND, ONLY COMPLEXES CONSISTING OF THE THREE ENZYME TYPES ARE ABLE TO DEGRADE ARABINANS TO MONOMERS EFFICIENTLY. MANY TECHNICAL ENZYME PREPARATIONS WERE FOUND TO LACK ONE OR MORE OF THE NECESSARY ACTIVITIES.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

WAGENINGEN UNIVERSITY
Address
Costerweg 50
Wageningen
Netherlands