DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Lee, Sang-Yup | - |
dc.contributor.advisor | 이상엽 | - |
dc.contributor.author | Choi, Eun-Jung | - |
dc.contributor.author | 최은정 | - |
dc.date.accessioned | 2013-09-11T01:07:46Z | - |
dc.date.available | 2013-09-11T01:07:46Z | - |
dc.date.issued | 2011 | - |
dc.identifier.uri | http://library.kaist.ac.kr/search/detail/view.do?bibCtrlNo=519648&flag=dissertation | - |
dc.identifier.uri | http://hdl.handle.net/10203/179971 | - |
dc.description | 학위논문(석사) - 한국과학기술원 : 생명화학공학과, 2011.2., [ v, 47 p. ] | - |
dc.description.abstract | C3 chemicals have been known as useful materials for its various applications in industry. There has been much effort to produce three carbon compounds via microbial process instead of petroleum-based chemical process due to environmental problem and shortage in petroleum resource. Here we describe methods for the production of C3 compounds (e.g. L-lactic acid and 1,2-propanediol) by metabolic engineering of Escherichia coli based on rational approach. E. coli was metabolically engineered for production of optically pure L-lactic acid using glucose. We investigated two kinds of L-specific lactate dehydrogenase (L-ldh) genes from Lactobacillus acidophilus and Lactobacillus brevis and found that L-ldhL. acidophilus was desirable for the production of L-lactate with little amount of by-products in E. coli. For the conversion of pyruvate to L-lactate preventing the production of D-lactate, indigenous lactate dehydrogenase (ldhA) gene was deleted in all of E. coli strains used in this study. We optimized the fermentation conditions varying gases for anaerobic atmosphere and attempting dual-phase fermentation for better glucose uptake system in E. coli. In addition, we further examined the effect of deleting alcohol dehydrogenase (adhE) gene on L-lactic acid production. The resulting ldhA strain produced 56.5 g/L of lactic acid from 74.8 g/L glucose in 35 h, representing a 75.5% conversion and a productivity of 1.61 g/L/h, at a yield of 1.52 mol/mol glucose. This is the best conversion rate and yield yet reported in E. coli. Also the resulting E. coli ldhA adhE strain produced 31.4 g/L of lactic acid from 31.9 g/L of glucose, representing a 98.4% conversion with trivial amount of by-products as well. This is the best yield yet reported in L-lactic acid producing microorganisms including Lactobacillus species and yeasts. The optical purity of the L-lactic acid was more than 99%. We further attempted to produce 1,2-propanediol in E. coli utilizing aforementioned L-lac... | eng |
dc.language | eng | - |
dc.publisher | 한국과학기술원 | - |
dc.subject | L-lactic acid | - |
dc.subject | 1 | - |
dc.subject | 2-propanediol | - |
dc.subject | metabolic engineering | - |
dc.subject | L-젖산 | - |
dc.subject | 1 | - |
dc.subject | 2-프로판디올 | - |
dc.subject | 대사 공학 | - |
dc.subject | 대장균 | - |
dc.subject | Escherichia coli | - |
dc.title | Metabolic engineering of escherichia coli for the production of L-Lactic Acid and 1,2-Propanediol | - |
dc.title.alternative | 대장균에서의 L-젖산과 1,2-프로판디올 생산을 위한 대사 공학적 연구 | - |
dc.type | Thesis(Master) | - |
dc.identifier.CNRN | 519648/325007 | - |
dc.description.department | 한국과학기술원 : 생명화학공학과, | - |
dc.identifier.uid | 020093547 | - |
dc.contributor.localauthor | Lee, Sang-Yup | - |
dc.contributor.localauthor | 이상엽 | - |
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