Power-to-vitamins: producing folate (vitamin B9) from renewable electric power and CO2 with a microbial protein system
Lisa Schmitz, Nicolai Kreitli, Lisa Obermaier, Nadine Weber, Michael Rychlik, Largus T. Angenent
Abstract
We recently proposed a two-stage Power-to-Protein technology to produce microbial protein from renewable electric power and CO 2 . Two stages were operated in series: Clostridium ljungdahlii in Stage A to reduce CO 2 with H 2 into acetate, and Saccharomyces cerevisiae in Stage B to utilize O 2 and produce microbial protein from acetate. Renewable energy can be used to power water electrolysis to produce H 2 and O 2 . A drawback of Stage A was the need for continuous vitamin supplementation. In this study, by using the more robust thermophilic acetogen Thermoanaerobacter kivui instead of C. ljungdahlii , vitamin supplementation was no longer needed. Additionally, S. cerevisiae produced folate when grown with acetate as a sole carbon source, achieving a total folate concentration of 6.7 mg per 100 g biomass with an average biomass concentration of 3 g l –1 . The developed Power-to-Vitamin system enables folate production from renewable power and CO 2 with zero or negative net-carbon emissions.