Extracellular expression of glucose inhibition-resistant Cellulomonas flavigena PN-120 ß-glucosidase by a diploid strain of Saccharomyces cerevisiae.
Arch Microbiol
; 196(1): 25-33, 2014 Jan.
Article
em En
| MEDLINE
| ID: mdl-24217872
ABSTRACT
The catalytic fraction of the Cellulomonas flavigena PN-120 oligomeric ß-glucosidase (BGLA) was expressed both intra- and extracellularly in a recombinant diploid of Saccharomyces cerevisiae, under limited nutrient conditions. The recombinant enzyme (BGLA¹5) expressed in the supernatant of a rich medium showed 582 IU/L and 99.4 IU/g dry cell, with p-nitrophenyl-ß-D-glucopyranoside as substrate. BGLA¹5 displayed activity against cello-oligosaccharides with 2-5 glucose monomers, demonstrating that the protein is not specific for cellobiose and that the oligomeric structure is not essential for ß-D-1,4-bond hydrolysis. Native ß-glucosidase is inhibited almost completely at 160 mM glucose, thus limiting cellobiose hydrolysis. At 200 mM glucose concentration, BGLA¹5 retained more than 50 % of its maximal activity, and even at 500 mM glucose concentration, more than 30 % of its activity was preserved. Due to these characteristics of BGLA¹5 activity, recombinant S. cerevisiae is able to utilize cellulosic materials (cello-oligosaccharides) to produce bioethanol.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Proteínas Recombinantes
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Beta-Glucosidase
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Cellulomonas
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article