Production of organic acids by fermentation of Syngas

本项目的目的是评估利用合成气发酵生产平台化学品的可行性。木质纤维生物质中糖的释放仍然受到高昂的酶成本和加工过程中产生的抑制剂的阻碍。上游流程需要针对不同的生物质来源进行定制。此外，一些微生物，特别是酿酒酵母，只能有效地利用C6糖，而不是占总碳水化合物很大比例的C5糖。另一种方法是将生物质气化以产生合成气(一氧化碳和氢气)，合成气可以作为羧基营养(CO利用)微生物的生长底物。气化可以应用于所有不同的生物质来源，甚至可以应用于较低等级的材料，如城市垃圾。此外，所有的碳都被释放出来用于发酵，甚至木质素成分也是如此，这是其他加工方案中无法获得的。不幸的是，羧基营养菌没有糖发酵异养菌研究得那么深入，而且看起来自然地只产生有限范围的产物，如醋酸盐和乙醇。该项目旨在通过评估利用代谢工程扩大CO发酵产品的范围以包括有价值的平台化学品的潜力来开辟新的领域。

The aim of this project is to evaluate the feasibility of producing platform chemicals by the fermentation of Syngas. The release of sugars from lignocellulosic biomass is still hindered by high enzyme cost and generation of inhibitors during processing. Upstream processes need to be customised for different biomass sources. Furthermore, some microorganisms, notably Saccharomyces cerevisiae, can only utilise effectively C6 sugars and not the C5 sugars that make up a significant proportion of the total carbohydrate. An alternative approach is gasification of the biomass to generate Syngas (carbon monoxide and hydrogen) which can act as a growth substrate for carboxydotrophic (CO-utilising) microorganisms. Gasification can be applied to all different biomass sources and even lower grade materials such as municipal wastes. Furthermore all of the carbon is released for fermentation, even the lignin component which is not available from other processing options. Unfortunately carboxydotrophs are not as well-studied as sugar fermenting heterotrophs and appear naturally to produce only a restricted range of products such as acetate and ethanol. This project aims to break new ground by evaluating the potential to use metabolic engineering to broaden the range of products from fermentation of CO to include valuable platform chemicals.