木質醋酸菌(Gluconacetobacter xylinus舊稱Acetobacter xylinum) 醱酵所形成之白色膠狀纖維素層-細菌纖維素(Bacterial cellulose，BC)，又稱那塔(Nata)，具有高純度的纖維素、奈米級結構及高機械強度，被廣泛應用於食品和生物材料。

在木質醋酸菌代謝葡萄糖生成細菌纖維素的過程中，因為菌體細胞膜上及胞內之葡萄糖脫氫酶(GDH)的存在，會將部份之葡葡糖反應轉換成葡萄糖酸，因而降低培養液之pH值，不利於菌體細胞之生長，並且消耗掉原來可轉化為細菌纖維素之葡萄糖，而降低了細菌纖維素之產量及收率。因此本研究運用基因同源重組之原理，將所建構含葡萄糖脫氫酶缺陷基因之質體轉形入木質醋酸菌中，與染色體上之GDH基因進行同源交換，來破壞菌體細胞之GDH之功能，將抗生素篩選得之GDH活性突變株近一步以 PCR 確認GDH突變基因之存在，此外也分析此突變株之葡萄糖脫氫酶活性量與葡萄糖酸含量確定突變株不具GDH活性；靜置培養產細菌纖維素時，突變菌株的細菌纖維素產量雖不如預期，但是單位葡萄糖消耗下所產生的細菌纖維素收率較原生菌株提升28%左右。

Gluconacetobacter xylinus (Acetobacter xylinum) when grows statically can produce white pellicle at the interface of air-liquid. This pellicle is consisted of high purity cellulose nanofibers. Various carbon source can be utilized by G. xylinus to produce bacterial cellulose (BC). Glucose is the most commonly used carbon source for BC production.
However, the membrane-bond and cytosol glucose dehydrogenases (GDH) of G. xylinus will catalyze glucose into gluconic acid, thus decreases the pH value of the culture. The low pH is not favorable for the growth of G. xylinus and BC production. In addition, the production yield of BC from glucose will also be significantly decreased. In this research, we knocked-out GDH gene of G. xylinus by homologous recombination of a defect GDH gene fragment. A plasmid containing a GDH gene fragment with ampicillin resistance gene as an insert was constructed. After transformation and selection on ampicillin agar plate, a GDH-deficient transformant was obtained and confirmed by PCR screening. The GDH(-) strain was proved to have no GDH activity by colorimetric method and no gluconic acid production detected by HPLC. The GDH(-) strain can also produce BC but with a lesser amount. In term of BC yield based on glucose consumption, the GDH(-) strain is about 28% higher than the wide type strain.

Alaban, C. A. (1967). "Nata de coco” bacterium or “Nata” formation in coconut water." Phil. Agric. 45: 490-515.
Cannon, R. E. and S. M. Anderson (1991). "Biogenesis of Bacterial Cellulose." Critical Reviews in Microbiology 17(6): 435-447.
Deppenmeier, U. Deppenmeier, et al. (2002). "Biochemistry and biotechnological applications of Gluconobacter strains." Applied Microbiology and Biotechnology 60(3): 233-242.
Dudman, W. F. (1959). "Cellulose production by Acetobacter acetigenum in defined medium." J Gen Microbiol 21(2): 327-337.
Duine, J. A. (1999). "The PQQ story." Journal of Bioscience and Bioengineering 88(3): 231-236.
Embuscado ME, M. J., BeMiller JN. (1994). "Bacterial cellulose.Ⅰ. Factors affecting the production of cellulose by Acetobacter xylinum." Food Hydrocoll 8(5): 407-418.
Garrity, G. B., Don J.; Krieg, Noel R.; Staley, James T. (Eds.) (2005) "Bergey's manual of systematic bacteriology " Volume Two: The Proteobacteria (Part C), 72-81.
Garrity, G. M. B., David R.; Castenholz, Richard W. (Eds.) (1984). Bergey's Manual of Systematic Bacteriology Volume One : The Archaea and the Deeply Branching and Phototrophic Bacteria, Williams & Wilkins.
Haigler, C. H., A. R. White, et al. (1982). "Alteration of in vivo Cellulose Ribbon Assembly by Carboxymethylcellulose and Other Cellulose Derivatives." The Journal of Cell Biology 94(1): 64-69.
Kouda, T., T. Naritomi, et al. (1997). "Effects of oxygen and carbon dioxide pressures on bacterial cellulose production by Acetobacter in aerated and agitated culture." Journal of fermentation and bioengineering 84(2): 124-127.
Kulháneka, M. and L. N. Saul (1989). Microbial Dehydrogenations of Monosaccharides. Advances in Applied Microbiology, Academic Press. Volume 34: 141-182.
Lapuz , M. M., Gallardo, E. G., and Dalo, M. A. (1967). "The Nata organism-Cultural requirement, characteristics and identify.." Philip. J. Sci. 96(2): 91-96.
Masaoka, S., Ohe, T. and Sakota, N. (1993). "Production of cellulose from glucose by Acetobacter xylinum." Journal of fermentation and bioengineering.
Matsushita, K., M. Ameyama, et al. (1982). D-Glucose dehydrogenase from Pseudomonas fluorescens, membrane-bound. Methods in Enzymology, Academic Press. Volume 89: 149-154.
Okiyama, A., Shirae, H., Kano, H. and Yamanaka, S. (1992). "Bacterial cellulose I. Two-stage fermentation process for cellulose production by Acetobacter acet." Food-Hydrocoll. 6(5): 471-477.
Oubrie A, R. H., Kalk KH, Olsthoorn AJ, Duine JA, Dijkstra BW. (1999). "Structure and mechanism of soluble quinoprotein glucose dehydrogenase." The EMBO Journal 18(19): 5187-5194.
Peter De Wulf, K. J., Erick J. Vandamme, (1996). "Improved cellulose formation by an Acetobacter xylinum mutant limited in (keto)gluconate synthesis." Journal of Chemical Technology & Biotechnology 67(4): 376-380.
Ross, P., R. Mayer, et al. (1991). "Cellulose biosynthesis and function in bacteria." Microbiol. Mol. Biol. Rev. 55(1): 35-58.
Shigematsu, T., K. Takamine, et al. (2005). "Cellulose Production from Glucose Using a Glucose Dehydrogenase Gene (gdh)-Deficient Mutant of Gluconacetobacter xylinus and Its Use for Bioconversion of Sweet Potato Pulp." The Society for Biotechnology, Japan 99(4): 415-422.
Toyosaki, H. N., T., Seto, A., Matsuoka, M., Tsuchida, T. and Yoshinaga, F. (1995). "Screening of bacterial cellulose-producing Acetobacter strains suitable for agitated culture." Biosci. Biotech. Biochem 59(8): 1498-1502.
Vandamme, E. J., S. De Baets, et al. (1998). "Improved production of bacterial cellulose and its application potential." Polymer Degradation and Stability 59(1-3): 93-99.
Williams, W. S. and R. E. Cannon (1989). "Alternative Environmental Roles for Cellulose Produced by Acetobacter xylinum." Appl. Environ. Microbiol. 55(10): 2448-2452.
Yaping Chao, Takehiko Ishida, et al. (2000). "Bacterial cellulose production by Acetobacter xylinum in a 50-L internal-loop airlift reactor." Biotechnology and Bioengineering 68(3): 345-352.
吳建一. "纖維素原料之展望與應用." from http://beebt.dyu.edu.tw/.
陳筱婷 (2005). 透明顫菌血紅蛋白表現對木質醋酸菌生長及細菌纖維素生產之效應, 國立台灣科技大學化學工程系研究所碩士論文.
鄭海鵬 (2001). 多重網狀導流板氣舉式反應器之規模放大及其在細菌纖維素生產上之應用, 國立清華大學化學工程系研究所碩士論文.