NAD(+)-dependent xylitol dehydrogenase (xdhA) and L-arabitol-4-dehydrogenase (ladA) deletion mutants of Aspergillus oryzae for improved xylitol production

作者：Mahmud A; Hattori K; Hongwen C; Kitamoto N; Suzuki T^*; Nakamura K; Takamizawa K

来源：Biotechnology Letters, 2013, 35(5): 769-777.

DOI：10.1007/s10529-013-1144-3

• Aspergillus oryzae
• Deletion mutant L-Arabitol-4-dehydrogenase
• Xylitol Xylitol dehydrogenase

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 (a dagger 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.

• 出版日期2013-5
• 单位华侨大学