Physiological role of the FDH1 gene in methylotrophic yeast Komagataella phaffii and carbon recovery as formate during methylotrophic growth of the fdh1-deletion strain

During methylotrophic growth of Komagataella phaffii, a large amount of carbon is lost as CO2. In this study, we aimed to construct a recovery system for carbon atoms, which emit as CO2 along the methanol dissimilation pathway in the form of formate when using strain fdh10, the deletion mutant of formate dehydrogenase gene (FDH1). Strain fdh10 showed a severe growth defect when using methanol as the sole carbon source. However, using YPM medium (1 % yeast extract, 2 % peptone and 1 % methanol) with pH adjustment, the strain recovered methylotrophic growth and methanol utilization, accumulating high levels of extracellular formate in the medium. In strain fdh10, the final carbon conversion rate of formate from methanol reached 12.9 % by batch cultivation. Moreover, by fed-batch cultivation in a jar fermentor, the formate productivity of strain fdh10 achieved approximately 540 mM. These results indicated that strain fdh10 possessed a high potential for recovering carbon atoms as formate, which can be a valuable precursor for various (c) 2025, The Society for Biotechnology, Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.