earticle

영어

The fermentation of glucose by several bacteria such as Klebsiella oxytoca, Klebsiellar pneumonia, Bacillus subtilis, Aeromonas hydrophilia and several species of Serratia yields 2,3-Butanediol as one of the products while secondary products formed acetoin, ethanol, lactic acid, and acetic acid. 2,3-Butanediol is a versatile bio-product for synthesis rubber polymers and solvents with a carbon chain length of four and two reactive sites. However the efforts of changing metabolic fluxes radically is known to be more challenging to determine which pathways should be modified in the classic genetic engineering. In this work, we constructed a model based on pyruvate distribution yielding 2,3-Butanediol and other byproducts. Our aim is to find a best mutant yielding 2,3-butanediol with the help of in silico experiments, thus the direct in silico experiments simulate the time scale concentration profiles based on the enzyme kinetics in combination with metabolic control analysis and metabolic flux analysis,. Based on Escherichia coli and Klebsiella bacteria enzyme database, several virtual mutants has been developed, simulated as well as combined with experiments confirmation. The results showed that the knockout of lactate dehydrogenase could decrease the production of lactate while increase the 2,3-Butanediol yield; NAD and NADH balance had fierce control on the reaction network; in addition other byproducts’ deletions would as well enlarge the productivity of 2,3-Butanediol.