The Establishment Of The Breeding Model Of Klebsiella Oxytoca 2,3-butanediol High-producing Strain And The Optimization Of Fermentation Conditions

2,3-butanediol and its derivates were important raw materials in chemical industry because of its extensive application in various fields such as in transport fuels production,in the food products,in the manufacturing of printing inks,explosives and plasticizes,pharmaceutical carriers and a precursor of many synthetic polymers and resins.Fermentation using microorganisms focused mainly on the environmental aspects.Among all these,2,3-butanediol was the most promising bulk chemical which had attracted worldwide attention.The key of this work was to improve the production of 2,3-butanediol by transforming.In this current study,2,3-butanediol production by Klebsiella oxytoca.Acquiring the strain which hereditary stability is well and produces a number of 2,3-butanediol production.Investigated and improved 2,3-butanediol production.A mutant strain U7HN9UN5N2 was obtained from original KO by mutagenesis treatment of UV mutation?He-Ne mutation?NTG mutation and compound mutation.A strain was isolated from CaCO3 plate and the ability of toleration and HPLC detect 2,3-butanediol production yield separating.Fermentation results showed that mutant had a 30.12%increase in 2,3-butanediol production(20.56±0.38g/L)and a 37.50%increase in yield(0.32±0.76g/g).Genetic stability analysis on mutant indicated that the production of 2,3-butanediol production was very stable.The next study was obtained from Klebsiella oxytoca.The adc?als and ar gene amplified by PCR respectively and combined with clone vector.These recombination cloning vector transform respectively to E.coli DH5a.Retrieving target genes and combining with expression vector transform to Klebsiella oxytoca mutant.The mutant could over express key enzyme and make more carbon source flow direction to 2,3-butanediol pathway.By this way could improve 2,3-butanediol production.It could improve 2,3-butanediol production to24.55g/L and advanced 35%.The success of the subject has the guiding significance to construct the genetic engineering strain for 2,3-butanediol production to some extent.And it makes the industrialized production of the 2,3-butanediol realize sooner.