Biosynthesis of bioplastics from CO2 by Cupriavidus necatorH16

背景：基于一碳（C1）原料（如二氧化碳和甲烷）发酵的生物过程在支持未来从非食物资源中可持续生产化学品和燃料方面具有巨大潜力。此外，通过将钢铁制造、炼油、煤炭和天然气/页岩气产生的废气转化为有价值的产品，这些过程将大大有助于减少温室气体（GHG）的排放。Cupriavidus necator H16（以前称为Ralstonia eutropha）是一种革兰氏阴性，非孢子形成，兼性化能石自养细菌，能够在有氧条件下在有机基质或H2和CO2上生长。其以二氧化碳为唯一碳源的生长能力使其成为从废气中可持续生产高价值平台化学品的有吸引力的底盘生物。在营养限制条件下，C. necator能够合成大量（高达92%）聚（3-羟基丁酸酯）或PHB，这是一种可生物降解和生物相容性的天然聚合物。这种天然合成的生物塑料具有相对较差的物理、热和机械性能（非常脆，高度结晶，熔点高）。因此，从廉价和丰富的原料中生产具有改进性能的可选均聚物和共聚物是非常需要的。目的：本项目的目的是通过代谢工程对Cupriavidus necator H16进行改造，以生产具有理想物理和机械性能的非天然均聚物，如3-羟基丙酸酯（3HP）和含有3HP的共聚物（即3HP）。聚（3-羟基丙酸-co-3-羟基丁酸酯）（P(3HP-co-3HB)）)该项目将与现有项目整合，优化合成新型pha的单体生产。培训：该项目将在诺丁汉的BBSRC/EPSRC合成生物学研究中心（SBRC）进行，该中心由90多名研究生和博士后研究人员组成。该研究将允许在独特的多学科环境中进行培训，包括有氧气体发酵，合成生物学，微生物生理学，代谢工程和计算机建模。

BACKGROUND: Biological processes based on fermentation of one carbon (C1) feedstocks (such as carbon dioxide and methane) have a great potential in supporting the future sustainable production of chemicals and fuels from non-food resources. In addition, these processes would greatly contribute to the 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. Under nutrient limiting conditions, C. necator is capable of synthesizing large amounts (up to 92%) of poly (3-hydroxybutyrate) or PHB, a biodegradable and biocompatible natural polymer. This naturally synthesised bioplastic has relatively poor physical, thermal and mechanical properties (very brittle, highly crystalline, has a high melting temperature). Production of alternative homopolymers and copolymers with improved properties from cheap and abundant feedstock is therefore greatly desired.AIM: The aim of this project is to metabolically engineer Cupriavidus necator H16 to produce non-natural homopolymers with desired physical and mechanical properties, such as 3-hydroxypropionate (3HP) and copolymers containing 3HP (ie. poly(3-hydroxypropionate-co-3-hydroxybutyrate) (P(3HP-co-3HB))) from CO2. The project will integrate with current projects optimising the production of monomers for the synthesis of novel PHAs.THE TRAINING: The project will be carried out within the BBSRC/EPSRC Synthetic Biology Research Centre (SBRC) at Nottingham which comprises 90+ graduate and postdoctoral researchers. The study will allow for training in a unique multidisciplinary environment, incorporating aerobic gas fermentation, Synthetic Biology, microbial physiology, metabolic engineering and computer modelling.