Physiology and genetics of ethanologenesis in the acetogenic bacterium Acetobacterium woodii

  • The acetogenic model bacterium Acetobacterium woodii is well-known to produce acetate by homoacetogenesis from sugars, but under certain conditions minor amounts of ethanol are produced in addition. Here, we have aimed to identify physiological conditions that increase electron and carbon flow towards ethanol production. Ethanol was only produced from fructose but not from H2 + CO2, formate, pyruvate, lactate or alanine. In the absence of Na+, the Wood–Ljungdahl pathway (WLP) of acetate formation is not functional. Therefore, the ethanol yield increased to 0.42 mol/mol (ethanol/fructose) with an ethanol/acetate ratio of 0.28 mol/mol. The presence of bicarbonate/CO2 stimulated electron and carbon flow through the WLP and led to less ethanol produced. Of the 11 potential alcohol dehydrogenase genes, the most upregulated during ethanologenesis was adh4. A deletion of adh4 led to an increase in ethanol production by 100% to a yield of 0.79 mol/mol (ethanol/fructose); this correlated with an increase in transcript abundance of adh6. In sum, our studies revealed low Na+ and bicarbonate/CO2 as factors that trigger ethanol formation and that a deletion of adh4 drastically increased ethanol formation in A. woodii.
Author:Jimyung Moon, Volker MüllerORCiD
Parent Title (English):Environmental microbiology
Place of publication:Oxford [u.a.]
Document Type:Article
Date of Publication (online):2021/08/27
Date of first Publication:2021/08/27
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2022/07/11
Page Number:12
First Page:6953
Last Page:6964
We are indebted to the European Research Council (ERC) for financial support under the European Union's Horizon 2020 research and innovation program (ACETOGENS, Grant Agreement No. 741791).
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - Namensnennung 4.0