| Summary: | 碩士 === 元智大學 === 生物科技與工程研究所 === 105 === Biodiesel is one of the hottest choices among on green energies. However, the byproduct-crude glycerol would be made from the preparation process of biodiesel. Hence, to utilize the crude glycerol to synthesize other bioproducts will raise the efficiency of green energy. This study attempted to evaluate the feasibility by crude glycerol (CG) as a carbon source for Klebsiella pneumoniae to produce 1,3-propandiol (1,3-PDO). Meanwhile, two vital factors (glucose and ammonium sulfate) were included to examine the fed-batch strategy for improving the production of 1,3-PDO. Two-stage fermentation strategy was carried out in this study. Stage 1 was to find out the proper feeding time, feeding concentration and feeding frequency by 250 mL flasks. The scaling up experiment of stage 2 was conducted in 5L bioreactor based on the experimental results in stage 1. When 34 g/L of CG as a carbon source by K. pneumoniae for 48h, the production of 1,3-PDO could achieve 14.21 g/L. Besides, the 2% of glycerol and 1 g/L of glucose (or 3.4 mM ammonium sulfate) was fed at 24h-, 36h- and 48h-cultivation by repeated fed-batch strategy, respectively. The experiment results showed using the 2% of glycerol and 1 g/L of glucose as feeding source, the production of 1,3-PDO could achieve 21.75 g/L. Additionally, using the 2% of glycerol and 3.4 mM of ammonium sulfate as feeding source were fed at 24h-, 36h- and 48h-cultivation, the production of 1,3-PDO could achieve 34.03 g/L. The production of 1,3-PDO using the 2% of glycerol and 3.4 mM of ammonium sulfate as feeding source was higher than those using 2% of glycerol and 1 g/L of glucose (around 1.56-fold) and batch cultivation (around 2.39-fold). Furthermore, the most proper agitation and aeration in 5L stir tank bioreactor were 100 rpm and 0.5 vvm, respectively. The production of 1,3-PDO under this condition can achieve 13.21 g/L. This study proved that K. pneumoniae not only can utilize CG as a carbon source for producing 1,3-PDO, but find out the best fed-batch strategy by evaluating feeding time, feeding concentration and feeding frequency.
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