Cellulose production from glucose using a glucose dehydrogenase gene (gdh)-deficient mutant of Gluconacetobacter xylinus and its use for bioconversion of sweet potato pulp.
A gene fragment encoding a putative pyrroloquinoline quinone glucose dehydrogenase (PQQ GDH) was cloned from a bacterial cellulose (BC)-forming acetic acid bacterium, Gluconacetobacter xylinus (=Acetobacter xylinum) strain BPR 2001, which was isolated as a high BC producer when using fructose as the carbon source. A GDH-deficient mutant of strain BPR 2001, namely GD-I, was then generated via gene disruption using the cloned gene fragment. Strain GD-I produced no gluconic acid but produced 4.1 g.l(-1) of BC aerobically in medium containing glucose as the carbon source. The ability of strain GD-I to convert glucose to BC was approximately 1.7-fold higher than that of the wild type. Strain GD-I was also able to produce 5.0 g.l(-1) of BC from a saccharified solution, which was derived from sweet potato pulp by enzymatic saccharification. Supplementation of ethanol during aerobic cultivation further increased the concentration of BC produced by strain GD-I to 7.0 g.l(-1). The rate of conversion from glucose to BC under these cultivation conditions was equivalent to that of strain BPR 2001 cultivated with fructose as the carbon source.
Shigematsu
Toru
T
Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto City, Kumamoto 860-8555, Japan. shige@kumamuto-u.ac.jp
Takamine
Kazunori
K
Kitazato
Masaya
M
Morita
Tetsuya
T
Naritomi
Takaaki
T
Morimura
Shigeru
S
Kida
Kenji
K
D001711:Biotransformation; D002482:Cellulose / Q000096:biosynthesis*; D003247:Conservation of Natural Resources / Q000379:methods; D024861:Genetic Enhancement / Q000379:methods; D041822:Gluconacetobacter xylinus / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D042843:Glucose 1-Dehydrogenase / Q000172:deficiency* / Q000235:genetics*; D007220:Industrial Waste / Q000517:prevention & control*; D027723:Ipomoea batatas / Q000382:microbiology*; D008657:Metabolic Clearance Rate; D009154:Mutation; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000378:metabolism; D012037:Refuse Disposal / Q000379:methods
D007220:Industrial Waste; D011994:Recombinant Proteins; D002482:Cellulose; D042843:Glucose 1-Dehydrogenase; D005947:Glucose