Onishi N, Kira I, Yokozeki K
Central Research Laboratories of Ajinomoto Co. Inc., Kawasaki-shi, Japan.
Lett Appl Microbiol. 1996 Oct;23(4):253-6. doi: 10.1111/j.1472-765x.1996.tb00077.x.
Galacto-oligosaccharide (Gal-OS) was produced from lactose by a yeast, Sirobasidium magnum CBS6803. With toluene-treated resting cells, 136 mg ml-1 of Gal-OS was produced from 360 mg ml-1 of lactose at 50 degrees C for 42 h. Then, the yield of Gal-OS was increased by a culture method in which cell growth followed the enzymatic reaction: 224 mg ml-1 of Gal-OS was produced at 30 degrees C for 60 h. Finally, combination of the toluene-treated resting cells and glucose oxidase plus catalase was applied to improve productivity by the removal of a by-product, glucose, which inhibits the Gal-OS production, from the reaction mixture. In this case, 242 mg ml-1 of Gal-OS was produced at 50 degrees C for 42 h without cell growth. The structure of the major product was identified as 4'-galactosyl-lactose.
低聚半乳糖（Gal-OS）由乳糖假丝酵母（Sirobasidium magnum CBS6803）从乳糖中产生。使用经甲苯处理的静止细胞，在50℃下42小时，从360mg/ml的乳糖中产生了136mg/ml的Gal-OS。然后，通过细胞生长跟随酶促反应的培养方法提高了Gal-OS的产量：在30℃下60小时产生了224mg/ml的Gal-OS。最后，应用经甲苯处理的静止细胞与葡萄糖氧化酶加过氧化氢酶的组合，通过从反应混合物中去除抑制Gal-OS产生的副产物葡萄糖来提高生产率。在这种情况下，在50℃下42小时无细胞生长的情况下产生了242mg/ml的Gal-OS。主要产物的结构被鉴定为4'-半乳糖基乳糖。
