Repeated-batch food waste fermentation for n-caproate production with reduced hydroxide use and no external electron donor addition

Fed-batch food waste fermentation was done without pH control for n-caproate production in an open microbiome. Acidification was steered towards lactate and, subsequently, chain elongation to n-butyrate and n-caproate was observed. Lactate was a key electron donor and its consumption during chain elongation helped to reduce the chemicals use for pH control.