Optimization Of 1,3-Propanediol Fermentation Process

1,3-propanediol(1,3-PDO)is an important chemical raw material developed in the early 1990s,mainly used in printing and dyeing and textiles,engineering plastics,coatings and inks and other fields.It is an important raw material for PTT polyester fiber synthesis.At present,the global 1,3-PDO production capacity of 300,000 tons,still far from being able to meet the market demand of more than one million tons,with huge room for development.In this paper,there are three aspects:K.pneumoniae's laboratory small test optimization and improvement part;thousand tons of industrialization pilot test amplification;for the industrialization of the actual needs of the fermentation process optimization and upgrading part.The fermentation experiment was carried out to explore the optimum amount of phosphate,ammonium sulfate and glucose in the latest strain KP.It was concluded that the optimum additions of phosphate and ammonium sulfate were 4.7 g/L and 2 g/L,respectively,and the optimal dosage of glucose was 10 g/L.The optimum fermentation temperature of KP was researched by designing the fermentation experiment at different temperatures for the sensitivity of Klebsiella to fermentation temperature.The effect of crude glycerol and pure glycerol on the fermentation results was compared in 5 L fermentor,and 5 L tank fermentation experiment was carried out in the pilot workshop to find the main problems of the pilot equipment.In the thousands of tons of pilot test device on the amplification test,located in Shandong Rising Group's thousands of tons of pilot-scale amplification device for a complex prerequisite debugging,pipeline reconstruction.In the 1 ton fermentation system,the yield of 1,3-propanediol was 67 g/L,and the comprehensive yield of 1,3-PDO and 2,3-butanediol reached 89 g/L.The conversion of 1,3-PDO from glycerol(g/g)have reached 0.51 in the 1 ton magnification system The comprehensive conversion of glycerol to diol reached 0.68 in a 1-ton system.On the basis of the wild type MGH78578 was constructed on the genetically engineered strains of wild type KCTC2242 model used in this experiment,through processing the experimental data of two batches of fermentation test of 37 ? and 30?,and metabolic flux analysis using the constructed model,analysis results show that the fermentation conditions of 30 DEG increase in cell ATP synthesis reducing power and generate related reaction intensity,intensity of reaction and reduced the glycolytic pathway and TCA pathway to extend the growth cycle of the cell,through the provision of adequate reducing power and energy,prolong the product synthesis time,get higher product accumulation.In the third part of the thesis,the exploratory process optimization experiment is carried out in the laboratory for the problems encountered in the actual magnification experiment.The effective fermentation time of the bacteria from the original 24 h to 72 h,the fermentation efficiency of the increase has a positive significance.In addition,the pretreatment method was explored in the fermentation supernatant,and the results showed that the decolorization of the fermentation supernatant could be achieved by the pretreatment of the activated carbon pretreatment.The supernatant obtained from 5 L fermentor was re-fermented by shake flask experiment.The accumulation of 1,3-PDO in fermentation broth increased from 72 g/L to 85 g/L,which confirmed the feasibility of the process.