Shih Ing-Lung, Yu Yun-Ti, Shieh Chwen-Jen, Hsieh Chien-Yan
Department of Environmental Engineering, Da-Yeh University, Chang-Hwa, Taiwan.
J Agric Food Chem. 2005 Oct 19;53(21):8211-5. doi: 10.1021/jf058084o.
To meet the industrial need of an efficient microbial method for increased levan production, Bacillus subtilis (natto) Takahashi, a commercial natto starter for preparing fermented soybeans (natto), was used to produce levan. After cultivation for 21 h, 40-50 mg of levan mL(-1) was produced in medium containing 20% (w/w) sucrose, which was approximately 50% yield on available fructose. The product consisted of two fractions with different molecular masses (1794 and 11 kDa), which were easily separated by fractionation using an ethanol gradient. The products were well characterized by GPC, 13C NMR, and 1H NMR. The various sugars and concentrations, initial pH, fermentation temperature, and agitation speed affected the levan production by B. subtilis (natto) Takahashi. Takahashi strain is the most efficient levan-producing strain among all of the B. subtilis strains tested and, as previously reported, it produced the highest yield of levan in the least time (21 h) under the common cultivation condition.
为满足工业上对提高果聚糖产量的高效微生物方法的需求，用于制备发酵大豆（纳豆）的商业纳豆发酵剂枯草芽孢杆菌（纳豆）高桥菌株被用于生产果聚糖。培养21小时后，在含有20%（w/w）蔗糖的培养基中产生了40 - 50毫克果聚糖/毫升，这相当于可利用果糖的约50%产率。产物由两个具有不同分子量（1794和11 kDa）的组分组成，通过乙醇梯度分级分离很容易分开。产物通过凝胶渗透色谱（GPC）、碳-13核磁共振（13C NMR）和氢-1核磁共振（1H NMR）进行了很好的表征。各种糖及其浓度、初始pH值、发酵温度和搅拌速度都会影响枯草芽孢杆菌（纳豆）高桥菌株的果聚糖产量。高桥菌株是所有测试的枯草芽孢杆菌菌株中最有效的果聚糖生产菌株，并且如先前报道的那样，在普通培养条件下，它在最短时间（21小时）内产生了最高的果聚糖产量。
