Metabolic engineering of Cupriavidus necator H16 for the production of high value chemicals

Cupriavidus necator H16 的代谢工程用于生产高价值化学品

• 批准号: 1645281
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1645281
• 关键词: Metabolic; engineering; Cupriavidus; necator; H16

Gas fermentation technology based on microbial conversion of carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) into chemicals and fuels has the potential to replace the existing fossil fuel based technologies and could provide a desirable alternative for the production of low carbon fuels for transportation, green chemicals or other valuable monomers that can be further processed into biopolymers and other high value chemicals. These processes would greatly contribute to reduction of Green House Gas (GHG) emissions by converting waste gasses from steel manufacturing, oil refining, coal and natural/shale gas into valuable products. Cupriavidus necator H16 (formerly known as Ralstonia eutropha) is a Gram-negative, non-spore forming, facultatively chemolithoautotrophic bacterium able to grow on organic substrates or H2 and CO2 under aerobic conditions. Its ability to grow on CO2 as sole carbon source makes it an attractive chassis organism for the sustainable production of high value platform chemicals from waste gasses. The aim of this project is to metabolically engineer Cupriavidus necator H16 to produce a valuable platform chemical, 3-hydroxypropanoic acid or 3HP. This intermediate product can be converted into acrylic acid, biodegradable polyesters, superabsorbent polymers and acrylic acids among other highly valued industrial products. It can be synthesised via glycerol, lactate, malonyl-CoA or beta-alanine intermediates via at least seven different biosynthetic pathways (Kumar, 2013). Three of the proposed pathways are thermodynamically favourable, and the most favourable pathway, proceeding via beta-alanine will be tested during this PhD for 3HP production in C. necator.The synthetic pathway for 3-HP production from beta-alanine has been previously described in E. coli and yeast. In yeast, the intermediate beta-alanine was converted into malonic semialdehyde either by the action of beta-alanine-pyruvate aminotransferase (BAPAT) or y-amino butyrate transaminase (GABT), and further reduced into 3-HP by the action of either 3-hydroxypropionate dehydrogenase (HPDH) or 3-hydroxyisobutyrate dehydrogenase (HIBADH). Homologues of all four candidate genes have been identified in the genome of C. necator H16 and will be subjected to enzyme characterisation. In addition, several synthetic operons will be built and tested for efficient production of beta-alanine and conversion of beta-alanine to 3HP

基于一氧化碳（CO），二氧化碳（CO2）和甲烷（CH4）的微生物转化的气体发酵技术有可能替代现有的基于化石燃料的技术，并且可以为生产低碳燃料的生产提供可取的替代品，以便将其用于运输，绿色化学物质或其他有价值的较高物质或其他有价值的怪物。这些过程将通过将钢制造，炼油，煤炭和天然/页岩气的废物转换为有价值的产品，从而有助于减少温室气体（GHG）排放。 Cupriavidus necator H16（以前称为Ralstonia furopha）是一种革兰氏阴性，非散发性形成的，在有氧条件下能够在有机底物或H2和CO2上生长的辅助性化学可养分细菌。它作为唯一碳源作为二氧化碳在二氧化碳上生长的能力使其成为可持续产生从废物中可持续生产的高价值平台化学物质的有吸引力的底盘生物。该项目的目的是代谢工程师Cupriavidus necator H16生产有价值的平台化学，3-羟基丙酸或3HP。该中间产物可以转化为丙烯酸，可生物降解的聚酯，超吸收性聚合物和丙烯酸，以及其他高度值得的工业产品。它可以通过至少七个不同的生物合成途径通过甘油，乳酸，丙二酰辅酶A或β-丙氨酸中间体合成（Kumar，2013）。提出的三个途径在热力学上是有利的，在该博士学位期间，将在C. necator中测试通过β-丙氨酸进行的最有利的途径。在酵母中，中间β-丙氨酸通过β-丙氨酸 - 丙氨酸 - 丙氨酸氨基转移酶（BAPAT）或Y-氨基丁酸酯跨氨基氨酸酶（GABT）的作用将其转化为雄性半二醛，并通过3-羟基甲酸二水酶（Hydroxypropionate delogenate）（HP）的作用进一步降低到3-HP中。 3-羟基异丁酸酯脱氢酶（Hibadh）。所有四个候选基因的同源物在C. necator H16的基因组中都被鉴定出来，并将受到酶的特征。此外，将建造和测试几个合成操纵子，以有效地生产β-丙氨酸以及将β-丙氨酸转化为3HP