甘油和半纤维素水解液共发酵生产1,3-丙二醇

建立了以K.pneumoniae为菌种,甘油和半纤维素水解液(HH)共发酵生产1,3-丙二醇(1,3-PDO)的体系。通过添加HH,1,3-PDO的质量浓度、甘油的转化率和生产力比甘油单独发酵分别提高了18.2%,24.4%,18.0%。HH中的木糖和甘露糖能显著提高1,3-PDO的产量和生物量,葡萄糖对1,3-PDO的合成产生抑制,半乳糖和阿拉伯糖对1,3-PDO的合成没有影响。与不添加抑制物相比,添加0.28 g/L糠醛时,生物量提高了12%,1,3-PDO的产量有微量提高;添加0.61 g/L甲酸盐时,对细胞生长和1,3-PDO的合成产生轻微抑制,分别降低了9.8%和1.1%;添加1.46 g/L乙酸盐时,细胞生长略有提高,1,3-PDO的质量浓度从8.77 g/L增至11.73 g/L。在补料分批发酵中添加HH,1,3-PDO的质量浓度、甘油的转化率和生产力分别提高到71.58 g/L,65%,1.93 g/(L.h),比甘油单独发酵分别提高了17.8%,25.0%,17.7%。

Synthesis of 1,3-Propanediol Through Cofermentation of Glycerol and Hemicellulose Hydrolyzate

A system for the synthesis of 1,3-propanediol(1,3-PDO) from glycerol and hemicellulose hydrolysates(HH) as the cosubstrate was established.By the addition of HH,the 1,3-PDO mass concentration,glycerol conversion and productivity increased by 18.2%,24.4% and 18.0% higher than those from glycerol alone,respectively.Xylose and mannose in HH enhanced the biomass and fermentation efficiency,glucose inhibited the 1,3-PDO synthesis,and galactose and arabinose have no effect on the fermentation.By the addition of 0.28 g/L furfural,the biomass increased by 12% higher than that without any inhibitors;by the addition of 0.61 g/L formate,the cell growth and 1,3-PDO production decreased 9.8% and 1.1% respectively;by the addition of 1.46 g/L acetate,the 1,3-PDO mass concentration increased from 8.77 g/L to 11.73 g/L.With the addition of HH in fed-batch fermentation,the 1,3-PDO mass concentration,glycerol conversion and productivity increased to 71.58 g/L,65% and 1.93 g/(L.h),which were 17.8%,25.0% and 17.7% higher than those from glycerol alone respectively.