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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Bioenergy Research » Research » Publications at this Location » Publication #276587
Title: Isolation and identification of beta-glucosidase from a new yeast for low-cost cellulose-to-ethanol conversion

Author
item Liu, Zonglin
item Weber, Scott
item Cotta, Michael

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/19/2012
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: We recently reported on a new yeast strain of Clavispora sp. NRRL Y-50464 that is able to utilize cellobiose as sole source of carbon and energy by producing sufficient native ß-glucosidase enzyme activity so no additional enzyme is needed for cellulosic ethanol production using simultaneous saccharification and fermentation (SSF). Eliminating the addition of external ß-glucosidase will reduce the cost of cellulosic ethanol production. In this study, we present results of the isolation and identification of a ß-glucosidase protein from strain Y-50464. A purified protein was obtained through multiple chromatographic steps at a 9.7-fold purity with a specific activity of 7.1 U/mg of protein at 45°C (pH 5.5). It demonstrated greater tolerance to glucose (reduced product inhibition) when compared with a commercial enzyme Novo 188. Using MALDI-TOF (Matrix-assisted laser desorption/ionization-Time-of-Flight) mass spectrometry and blast search of the NCBInr database (National Center for Biotechnology Information non-redundant), the protein was identified as a ß-glucosidase with a molecular weight of 93.3 kD. Complete amino acid sequence of this newly identified ß-glucosidase and its relationship to other closely related enzymes will be presented. Knowledge obtained from this study will aid large scale economic cellulosic ethanol production.