Scully, SM, Brown, AE, Mueller-Hilger, Y et al. (2 more authors) (2021) Influence of Culture Conditions on the Bioreduction of Organic Acids to Alcohols by Thermoanaerobacter pseudoethanolicus. Microorganisms, 9 (1). 162. pp. 1-24. ISSN 2076-2607
Abstract
Thermoanaerobacter species have recently been observed to reduce carboxylic acids to their corresponding alcohols. The present investigation shows that Thermoanaerobacter pseudoethanolicus converts C2–C6 short-chain fatty acids (SCFAs) to their corresponding alcohols in the presence of glucose. The conversion yields varied from 21% of 3-methyl-1-butyrate to 57.9% of 1-pentanoate being converted to their corresponding alcohols. Slightly acidic culture conditions (pH 6.5) was optimal for the reduction. By increasing the initial glucose concentration, an increase in the conversion of SCFAs reduced to their corresponding alcohols was observed. Inhibitory experiments on C2–C8 alcohols showed that C4 and higher alcohols are inhibitory to T. pseudoethanolicus suggesting that other culture modes may be necessary to improve the amount of fatty acids reduced to the analogous alcohol. The reduction of SCFAs to their corresponding alcohols was further demonstrated using 13C-labelled fatty acids and the conversion was followed kinetically. Finally, increased activity of alcohol dehydrogenase (ADH) and aldehyde oxidation activity was observed in cultures of T. pseudoethanolicus grown on glucose as compared to glucose supplemented with either 3-methyl-1-butyrate or pentanoate, using both NADH and NADPH as cofactors, although the presence of the latter showed higher ADH and aldehyde oxidoreductase (ALDH) activity.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/) |
Keywords: | biocatalysis; extremophile; thermophile; fusel alcohols; carboxylic acids; volatile fatty acids; bioreduction |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Mar 2021 12:58 |
Last Modified: | 04 Mar 2021 12:58 |
Status: | Published |
Publisher: | MDPI |
Identification Number: | 10.3390/microorganisms9010162 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:171759 |