5 years ago

Engineered Assimilation of Exogenous and Endogenous Formate in Escherichia coli

Engineered Assimilation of Exogenous and Endogenous Formate in Escherichia coli
Hezi Tenenboim, Arren Bar-Even, Oren Yishai, Steffen N. Lindner, Leander Goldbach
Decoupling biorefineries from land use and agriculture is a major challenge. As formate can be produced from various sources, e.g., electrochemical reduction of CO2, microbial formate-assimilation has the potential to become a sustainable feedstock for the bioindustry. However, organisms that naturally grow on formate are limited by either a low biomass yield or by a narrow product spectrum. The engineering of a model biotechnological microbe for growth on formate via synthetic pathways represents a promising approach to tackle this challenge. Here, we achieve a critical milestone for two such synthetic formate-assimilation pathways in Escherichia coli. Our engineering strategy involves the division of the pathways into metabolic modules; the activity of each module—providing at least one essential building block—is selected for in an appropriate auxotrophic strain. We demonstrate that formate can serve as a sole source of all cellular C1-compounds, including the beta-carbon of serine. We further show that by overexpressing the native threonine cleavage enzymes, the entire cellular glycine requirement can be provided by threonine biosynthesis and degradation. Together, we confirm the simultaneous activity of all pathway segments of the synthetic serine–threonine cycle. We go beyond the formate bioeconomy concept by showing that, under anaerobic conditions, formate produced endogenously by pyruvate formate-lyase can replace exogenous formate. The resulting prototrophic strain constitutes a substantial rewiring of central metabolism in which C1, glycine, and serine metabolism proceed via a unique set of pathways. This strain can serve as a platform for future metabolic-engineering efforts and could further pave the way for investigating the plasticity of metabolic networks.

Publisher URL: http://dx.doi.org/10.1021/acssynbio.7b00086

DOI: 10.1021/acssynbio.7b00086

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.