TY  - JOUR
A1  - Schwarz, Fabian M.
A1  - Ciurus, Sarah
A1  - Jain, Surbhi
A1  - Baum, Christoph
A1  - Wiechmann, Anja
A1  - Basen, Mirko
A1  - Müller, Volker
T1  - Revealing formate production from carbon monoxide in wild type and mutants of Rnf‐ and Ech‐containing acetogens, Acetobacterium woodii and Thermoanaerobacter kivui
T2  - Microbial biotechnology
N2  - Acetogenic bacteria have gained much attraction in recent years as they can produce different biofuels and biochemicals from H2 plus CO2 or even CO alone, therefore opening a promising alternative route for the production of biofuels from renewable sources compared to existing sugar‐based routes. However, CO metabolism still raises questions concerning the biochemistry and bioenergetics in many acetogens. In this study, we focused on the two acetogenic bacteria Acetobacterium woodii and Thermoanaerobacter kivui which, so far, are the only identified acetogens harbouring a H2‐dependent CO2 reductase and furthermore belong to different classes of ‘Rnf’‐ and ‘Ech‐acetogens’. Both strains catalysed the conversion of CO into the bulk chemical acetate and formate. Formate production was stimulated by uncoupling the energy metabolism from the Wood–Ljungdahl pathway, and specific rates of 1.44 and 1.34 mmol g−1 h−1 for A. woodii ∆rnf and T. kivui wild type were reached. The demonstrated CO‐based formate production rates are, to the best of our knowledge, among the highest rates ever reported. Using mutants of ∆hdcr, ∆cooS, ∆hydBA, ∆rnf and ∆ech2 with deficiencies in key enzyme activities of the central metabolism enabled us to postulate two different CO utilization pathways in these two model organisms.
Y1  - 2020
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/57036
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-570367
SN  - 1751-7915
VL  - 13
IS  - 6
SP  - 2044
EP  - 2056
PB  - Wiley-Blackwell
CY  - Oxford
ER  -