Chi Z, Liu Z
Department of Microbiology, Shandong University, Jinan, China.
Chin J Biotechnol. 1994;10(2):113-9.
In this study, high concentration alcoholic fermentation coordinated with saccharification from raw ground corn was performed at 30 degrees C, pH 4-5, in batch culture using Saccharomyces sp. H0 which was constructed by hybridization in this laboratory and the glucoamylase preparation produced on a large scale in China. The optimal conditions for high concentration ethanol production were that the amount of the glucoamylase preparation was 300 u/g of raw ground corn, the inoculum size of the yeast was 2.7 x 10(6) cells/ml, the fermentation temperature was 30 degrees C, the starting concentration of raw ground corn was 33.0% (w/v), and the fermentation period was 70 hr. At the end of fermentation, 17.5% (v/v) ethanol was yielded, with 0.19% reducing sugar, 3.5% total sugar and 16.0% cell viability remaining in the fermented mash. In the case of 36.0% (w/v) of the initial raw ground corn concentration, the strain could produce 18.0% (v/v) ethanol, leaving 0.81% reducing sugar and 5.1% total sugar in the media. We found that the glucoamylase preparation which is usually employed for saccharification of cooked starch could be used for efficient saccharification of raw ground corn starch.
在本研究中，使用本实验室通过杂交构建的酿酒酵母属H0菌株和国内大规模生产的糖化酶制剂，于30℃、pH 4 - 5条件下，在分批培养中进行高浓度酒精发酵并协同对磨碎的生玉米进行糖化。高浓度乙醇生产的最佳条件为：糖化酶制剂用量为300 u/g磨碎的生玉米，酵母接种量为2.7×10(6)个细胞/ml，发酵温度为30℃，磨碎的生玉米起始浓度为33.0%（w/v），发酵周期为70小时。发酵结束时，发酵醪中乙醇产量为17.5%（v/v），还原糖含量为0.19%，总糖含量为3.5%，细胞活力为16.0%。当初始磨碎的生玉米浓度为36.0%（w/v）时，该菌株可产生18.0%（v/v）的乙醇，培养基中残留还原糖0.81%，总糖5.1%。我们发现，通常用于熟淀粉糖化的糖化酶制剂可用于高效糖化磨碎的生玉米淀粉。
