Continuous hydrogen and caproate production in a two-stage anaerobic bioprocess: proof of concept

01/11/2020 to 31/10/2022

Organic wastes can be utilized as a feedstock for a chain-elongation process
for the production of valuable chemicals of five or more carbons. This can be performed by anaerobic populations in a microbiome reactor through reverse beta-oxidation, where short-chain carboxylic acids (C2-C5) can be sequentially reduced with acetyl-CoA (evolved from ethanol or lactate as electron donors) to produce medium-chain carboxylic acids, including n-caproate (C6), n-heptylate (C7), n-caprylate (C8), and others (1–3). The concept of coupling a primary fermentation to the production of medium-chain carboxylic acids is now an important research area because with smart bioprocess engineering a possibility exists that external electron donors do not need to be procured, but that they can be produced from the waste as well.