摘要
传统的L-乳酸发酵法生产以CaCO3为酸中和剂,在乳酸后提取中产生的大量石膏废渣不仅在过滤时造成较大的乳酸损失,而且由于废渣不易处理,对L-乳酸万吨级规模的生产将形成巨大的环保压力和废渣处理成本。为此,为了降低L-乳酸生产成本,该文采用氨水为酸中和剂,用筛选得到的一株米根霉RhizopusoryzaeJS-N02-02进行以氨水为中和剂的L-乳酸摇瓶、15L自动发酵罐的发酵试验。以玉米粉双酶水解糖为碳源,接种孢子浓度1×105个ml,以0.01%(NH4)2SO4为氮源,30℃,15L自动发酵罐连续5批发酵,平均总糖浓度为136.8gL,平均产酸达100.6gL,L-乳酸纯度达95.3%,糖酸转化率达71.6%。
For traditional L- lactic acid production process, in which CaCO3 was used as neutralizer, calcium sulfate residue from the recovery procedure, not only caused the loss of L - lactic acid during filtration but also increased the disposal cost, especially for the mass production of L - lactic acid at a ten- thousand- ton level. Therefore, fermentation with ammonia as neutralizer to replace CaCO3 was studied in shake- flask and 15L fermentation tank. Ammonia resistant strain Rhizopus oryzae JS - N02 - 02 was selected to ferment enzyme hydrolysate of corn at 30℃ in 15L fermentation tank, with the spore concentration of 1 × 10^5 cfu. ml^-1 inoculated and（ NH4 ）2 SO4 （0. 1g/L） as nitrogen source, the average total sugar concentration controlled at 136.8g/L, the average yield of lactic acid in 5 successive batches, reached 100.6g/L, the optical purity of L- lactic acid reached 95.3%, the lactate- glucose conversation rate reached 71.6%.
出处
《生物技术》
CAS
CSCD
2005年第4期65-67,共3页
Biotechnology
