Inventors:
Douglas B. Jordan - Peoria IL, US
Xin Liang Li - Morton IL, US
Christopher A. Dunlap - Dunlap IL, US
Terence R. Whitehead - Peoria IL, US
Michael A. Cotta - Edelstein IL, US
Assignee:
The United States of America as represented by the Secretary of Agriculture - Washington DC
International Classification:
C12P 19/02
C12N 9/00
C12N 9/26
C07H 21/04
US Classification:
435105, 435183, 435201, 536 232
Abstract:
Xylose-containing plant material may be hydrolyzed to xylose using a β-D-xylosidase which exhibits unexpectedly high activity. The enzyme has a kvalue for catalysis of approximately 185 secfor 1,4-β-D-xylobiose (X2) when measured at a pH of 5. 3 and a temperature of 25 C. ; this is at least 10-fold greater than reported for other xylosidases at 25 C. and their optimal pH. The enzyme also has an isoelectric point of approximately 4. 4. When reacted at a pH between about 4. 5 and about 7. 7, the β-D-xylosidase exhibits surprisingly high activity for hydrolyzing xylose-containing plant materials to xylose. The xylose released from plant materials may then be converted to other secondary products such as ethanol by fermentation or other reaction. This β-D-xylosidase may be used alone or in combination with other hydrolytic or xylanolytic enzymes for treatment of lignocellulosic or hemicellulosic plant materials or plant material hydrolysates or xylooligosaccharides.
