Project leader: Prof. Dr. Harmut Grammel


  • Andreas Witt,
  • Beryl Cancro

Financing: Bundesministerium für Bildung und Forschung

Program: Biotechnologie 2020plus - Basistechnologien für eine nächste Generation biotechnologischer Verfahren

Duration: 2018 – 2022

Partners: Max-Planck-Institut für Dynamik komplexer technischer Systeme, Magdeburg

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Project description

The problem of rising CO2 levels in the atmosphere as a major cause of global warming, makes it highly attractive to utilize CO2 as raw material for producing chemicals. Biocatalytic conversion using CO2-fixing enzymes is particularly interesting since enzymes generally operate with high specificity and selectivity at moderate environmental conditions.  We recently demonstrated that natural decarboxylases can be operated in the reverse CO2-fixing direction in synthetic combinations with low potential redox cofactors in vitro (1). We now incorporated further enzymes to establish a synthetic linear pathway for conversion of acetate and 2CO2 to the C4-dicarboxylic acid malate.

However, enzymatic reactions often depend on cofactors which have to be continuously replenished and lead to high costs in running biocatalytic systems. Furthermore, the accumulation of the used cofactors may cause inhibitory effects and reduce overall efficacy.

This project addresses the issue of enzymatic conversion of CO2 including cofactor recycling within a sustainable closed circular process. As cofactor recycling module illuminated chloroplast are incorporated to regenerate the cofactors ATP, NADPH, ferredoxin, and coenzyme A.

The pathway potentially provides a biocatalytic route to C4 dicarboxylic acid platform chemicals with CO2 as a substrate.


(1) Witt A, Pozzi R, Diesch S, Hädicke O, Grammel H. 2019. New light on ancient enzymes – in vitro CO2 fixation by pyruvate synthase of Desulfovibrio africanus and Sulfolobus acidocaldarius. FEBS J. 286(22):4494-4508. doi: 10.1111/febs.14981.

Chloroplast stroma:


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