BioChem - DOS

Low carbon fuels and commodity chemicals from waste gases - systematic approach to understand energy metabolism in a model acetogen

Green chemistry : an international journal and green chemistry resource : GC

Marcellin, Esteban; Behrendorff, James B.; Nagaraju, Shilpa; DeTissera, Sashini; Segovia, Simon; Palfreyman, Robin W.; Daniell, James; Licona-Cassani, Cuauhtemoc; Quek, Lake-ee; Speight, Robert; Hodson, Mark P.; Simpson, Sean D.; Mitchell, Wayne P.; Kö pke, Michael; Nielsen, Lars K.

<P>Gas fermentation using acetogenic bacteria offers a promising route for the sustainable production of low carbon fuels and commodity chemicals from abundant, inexpensive C1 feedstocks including industrial waste gases, syngas, reformed methane or methanol. <I>Clostridium autoethanogenum</I> is a model gas fermenting acetogen that produces fuel ethanol and 2,3-butanediol, a precursor for nylon and rubber. Acetogens have already been used in large scale industrial fermentations, they are ubiquitous and known to play a prominent role in the global carbon cycle. Still, they are considered to live on the thermodynamic edge of life and potential energy constraints when growing on C1 gases pose a major challange for the commercial production of fuels and chemicals. We have developed a systematic platform to investigate acetogenic energy metabolism, exemplified here by experiments contrasting heterotrophic and autotrophic metabolism. The platform is built from complete omics technologies, augmented with genetic tools and complemented by a manually curated genome-scale mathematical model. Together the tools enable the design and development of new, energy efficient pathways and strains for the production of chemicals and advanced fuels <I>via</I> C1 gas fermentation. As a proof-of-platform, we investigated heterotrophic growth on fructose <I>versus</I> autotrophic growth on gas that demonstrate the role of the Rnf complex and Nfn complex in maintaining growth using the Wood&ndash;Ljungdahl pathway. Pyruvate carboxykinase was found to control the rate-limiting step of gluconeogenesis and a new specialized glyceraldehyde-3-phosphate dehydrogenase was identified that potentially enhances anabolic capacity by reducing the amount of ATP consumed by gluconeogenesis. The results have been confirmed by the construction of mutant strains.</P><BR><BR><P>Graphic Abstract</P><P>Insight into energy metabolism of gas-fermenting acetogens using a systems level approach for sustainable production of fuels and chemicals.<BR><IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5gc02708j'><BR></P>

2016

The Royal Society of Chemistry

1463-9262

1463-9270

18

10

pp.3020-3028

10.1039/c5gc02708j

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART75908996