- 期刊
以Chitinibacter tainanensis分解幾丁質生產天然型N-乙醯葡萄糖胺
The Production of Natural Type N-acetyl Glucosamine from Chitin by Chitinibacter tainanensis
摘要
N-乙醯葡萄糖胺(N-acetylglucosamine, NAG)是天然多醣類幾丁質水解的最終產物，近年來已發現許多生理功能，包括關節炎治療以及腸胃道發炎疾病治療等。傳統製備NAG是採用濃鹽酸水解法，近年開發出酵素水解法，產物更為純淨，俗稱天然型N-乙醯葡萄糖胺。 本公司自台南縣稻田土壤中篩選出一株新種的細菌，經鑑定為新屬新種，並以發現地命名為Chitinibacter tainanensis。該菌可將幾丁質顆粒分解成可溶性的還原糖，轉化率達0.75g/g，若是以β-chitin為原料轉化率更高達0.98g/g。產物經分析後確認為NAG(N-acetylglucosamine, NAG)，濃縮結晶後可獲得白色針狀結晶，測其純度可達99%以上，產物經多項動物實驗測試確認其口服安全性以及對皮膚無刺激性，口味微甜，適宜應用於食品、化妝品及藥物製造。 探討Chitinibacter tainanensis生產N-乙醯葡萄糖胺的作用機轉，推測菌體係利用幾丁質分解因子(Chitin Degrading Factors, CDFs)將幾丁質分解成NAG，作為菌種生長之能源，並造成培養基酸化而使細菌凋亡，所產生之NAG不再被細菌消耗掉，累積於培養基中成為本製程之產物。進一步研究發現CDFs位於細菌表面，且細菌凋亡後的殘骸仍能分解幾丁質，證實本公司所提出之CDFs理論為正確。本方法必需倚賴生物體之參與，已突破舊有游離酵素作用機轉之觀念，為國際首創，故命名為生物轉化法。
並列摘要
N-acetyl glucosamine (NAG) is the final product of chitin degradation. It was recently promoted as a nutriceutical agent for patients with osteoarthritis and inflammatory diseases. Generally, NAG was prepared from chitin hydrolyzed by concentrated HCl. The enzymatic processes using environmentally friendly conditions were also performed to produce natural type NAG. A novel chitin-degrading aerobe named Chitinibacter tainanensis was isolated from a soil sample collected from Tainan County, and was proved to produce NAG. The yield was measured to be 0.75g/g using α-chitin as a substrate, while that was0.98g/g using β-chitin as a substrate. A needle type crystal was produced after concentration and crystallization, and the purity was measured to be higher than 99%. The product was proved to be feasible for edible or cosmetic usage by animal test. Chitin degrading factors (CDFs) were proposed to be the critical factors to degrade chitin in this method. When Chitinibacter tainanensis was incubated with chitin, CDFs were induced and chitin was converted to NAG. After consumption of NAG, the medium was acidified simultaneously, and the bacterium died. Then NAG was produced in the medium by chitin degradation. CDFs were found to be located on the surface of Chitinibacter tainanensis, even in the debris. The novel method was named bioconvertion method owing to using whole cell body as a catalyst.