Study On The Fermentation Of Recombinant Klebsiella Pneumoniae And Gene Knock Out Of Lactate Dehydrogenase

3-Hydroxypropionic acid (3-HP) is an important platform chemical, which can be transformed to variety of chemicals, such as acrolein and acrylic acid.3-HP becomes more and more important confirmed by the market.1,3-propanediol (1,3-PDO) is also a widely used platform chemical, which is mainly used in the synthesis of polyurethane and the new polyester (PTT) in industry. Currently, the market demand of these two chemicals becomes increasing.Based on the recombinant Klebsiella pneumoniae developed earlier in our lab, the fermentation using glycerol to produce3-HP and1,3-PDO was investigated. By examining the effect of different glycerol concentration and feeding strategy on the production, it was found that controlling glycerol concentration at20-30g/L resulted into the highest titer, which produces47.20g/L of3-HP and43.90g/L of1,3-PDO in26h. The intermittent addition glycerol obtained the highest yield of3-HP and1,3-PDO,0.35and0.38mo1/mol,respectively.In addition, glucose and glycerol utilized as co-substrates in fermentation to produce3-HP and1,3-PDO was also studied. Two-stage flask experiments were conducted. The results showed glucose had no effect on the production. In two-stage fed-batch fermentation, using nitrogen of0.1vvm in the glycerol feeding stage was conducive to the products formation.The lactate dehydrogenase-deficient recombinant K. pneumoniae strain was also attempt to construct.