摘要
中间产物3-羟丙醛在发酵液中的积累对Klebsiella pneumoniae细胞生长及1,3-丙二醇的合成有显著的抑制作用,而调节发酵的起始甘油浓度及控制发酵pH值可调控发酵液中3-羟丙醛的积累.当起始甘油质量浓度分别为20、30、50、70g/L的批式发酵中,发酵液中3-羟丙醛的积累的高峰分别为4.31、6.87、11.48及13.49mmol/L,当起始甘油质量浓度大于50g/L时,3-羟丙醛在到达积累高峰后不能被菌体有效转化,在发酵后期维持较高浓度,抑制了细胞生长及1,3-丙二醇的合成,发酵不能继续进行.控制发酵pH值为7.75～8.0可促进发酵液堆积的3-羟丙醛被迅速转化.在流加发酵中起始甘油质量浓度采用30g/L,发酵pH值控制为7.75条件下,发酵32 h,1,3-丙二醇质量浓度可达37.16g/L,1,3-丙二醇的生产强度和质量得率分别达到1.16g/(L·h)和52.66%.
3-Hydroxypropionaldehyde, an intermediate product during the 1,3-propanediol fermentation by Klebsiella pneumoniae, can inhibite cell growth and 1,3-propanediol production, but it can be controlled by regulating the initial glycerol concentration and pH value. In the batch culture with the initial glycerol concentration of 20, 30, 50 and 70 g/L, 3-hydroxypropionaldehyde concentration can reach the peak of 4.31,6.87, 11.48 and 13.49 mmol/L respectively. The 3- hydroxypropionaldehyde accumulated can＇t be converted effectively when the initial glycerol concentration is higher than 50 g/L, which led to the fermentation ceasing. A proper pH controlling strategy （pH = 7.75 - 8.0） can enhance the conversion of 3-hydroxypropionaldehyde in the broth and decrease the toxicity of 3-hydroxypropionaldehyde to the cell. During a fed-batch culture with the initial glycerol concentration of 30 g/L at a pH value of 7.75,1,3-propanediol concentration reached 37.16 g/L in 32 h of fermentation. Furthermore,the productivity and yield can be 1.16 g/（ L·h） and 52.66% （g/g） respectively.
出处
《现代化工》
EI
CAS
CSCD
北大核心
2005年第9期47-49,51,共4页
Modern Chemical Industry
基金
"十五"国家科技攻关计划资助项目(2001BA708B01-04)
