NADâº-dependent xylitol dehydrogenase (xdhA) and L-arabitol-4-dehydrogenase (ladA) deletion mutants of Aspergillus oryzae for improved xylitol production.
Biotechnol Lett
; 35(5): 769-77, 2013 May.
Article
em En
| MEDLINE
| ID: mdl-23436125
ABSTRACT
Xylitol dehydrogenase (XDHA) and L-arabitol dehydrogenase (LADA) are two key enzymes in xylan metabolism catalyzing the oxidation of xylitol to D-xylulose and arabitol to L-xylulose, respectively. In Aspergillus oryzae, XDHA and LADA are encoded by xdhA and ladA. We deleted xdhA and ladA and xdhA-ladA to generate mutants with decreased dehydrogenase activities and increased xylitol production. The mutants were constructed by homologous transformation into A. oryzae P4 (∆pyrG) using pyrG as a selectable marker. The xylitol productivity of the mutants was measured using D-xylose as the sole carbohydrate source. xdhA, ladA, and the double-deletion mutant produced, respectively, 12.4 g xylitol/l with a yield of 0.24 g/g D-xylose, 12.4 g/l with a yield of 0.33 g/g D-xylose, and 8.6 g/l at a yield of 0.26 g/g D-xylose.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Aspergillus oryzae
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Desidrogenase do Álcool de Açúcar
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Xilitol
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Deleção de Sequência
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D-Xilulose Redutase
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article