【摘要】 <正>维生素C(Vitamin C,简称Vc),又称L-抗坏血酸(L-Ascorbic acid)是人体必需的维生素,生理作用广泛,在医药和食品工业上均有重要地位。目前国内厂家多以我国发明的“二步发酵法”进行生产,即以D-山梨醇为原料生产2-酮基-L-古龙酸(以下简称2-KLG),然后制备维生素C。而近年来引起国内外普遍关注的是从D-葡萄糖串联发酵生产2-KLG的新工艺,以及采用基因工程技术,构建直接由D-葡萄糖转化生成2-KLG的基因工程菌的研究(图1)。1987年以来我国学者尹光琳等人采用了欧文氏菌(Erwinia sp.)和棒状杆菌(Corynebacterium sp.)进行串联发酵产生维生素C前体——2-酮基-L-古龙酸,并开展了一系列的研究。更多还原

【Abstract】 A strain of Corynebacterium sp. SCB 3058 could reduce 2, 5-diketo-L-gluconate to 2-keto-L-gulonic acid, which accumulated about 20 mg/ml in the broth after a period of 68~72 hours. The yield of 2-keto-L-gulonic acid from 2, 5-diketo-D-gluconate could be above 70mol%. The results of the fermentation showed that the inoculum age and pH control before the feeding of 2, 5-diketo-D-gluconate were very important. Although the strain SCB 3058 was strictly aerobic, low aeration rates were suitable for the conversion. The strain SCB 3058 also required a hydro-gen donor for the reduction, and 2, 5-diketo-D-gluconate broth was mixed with D-glucose before being fed.更多还原