Metabolic folate profiling as a function of time during cultivation suggests potential C2-metabolism in Saccharomyces cerevisiae

Abstract

Yeasts are reported to be rich in folates, a group of vitamers known to be involved in several biosynthetic reactions such as methylation reactions, oxidation and reduction processes, and nucleotide synthesis. Not being able to synthesize folates, humans rely on external folate supply. Here, we show the application of LC/MS-MS methods using SIDA (stable isotope dilution analysis) assays for the quantitative analysis of different folate mono- and polyglutamates during growth of Saccharomyces cerevisiae. Molecular networking (MN) was applied for detailed analysis of further folate metabolites. Highest folate contents of 13,120 μg/100 g were observed after 20 h of cultivation. The main vitamers 5-CH3-H4folate and H4folate decreased during cultivation, while 5-CHO-H4folate increased during cultivation. The hexa- and heptaglutamate of 5-CH3-H4folate accounted for >96% of the total 5-CH3-H4folate content. A shift of the major polyglutamate from hexa- to heptaglutamate was observed after 29 h. MN unraveled two groups of novel folates which could be assigned to a potentially existing C2-metabolism in yeast. In detail, 5,10-ethenyl-tetrahydrofolate and a further CO-substituted 5-CH3-H4folate were identified as hexa- and heptaglutamates. The latter was neither identified as 5-acetyl-tetrahydrofolate nor as EthylFox, the oxidation product of 5-ethyl-tetrahydrofolate. The structure needs to be elucidated in future studies.

Power-to-Vitamins: Producing Folate (Vitamin B9) from Renewable Electric Power and CO2with a Microbial Protein System

“…This distribution is consistent with other studies in which 5-CH3-H4folate and H4folate were the main vitamers after batch cultivation with glucose as a substrate, with up to 80% 5-CH3-H4folate of the total folate content. [28, 48, 50] To the best of our knowledge, this is the first study demonstrating folate biosynthesis from yeasts that was cultivated on acetate.…”

A New Direction for the Green, Environmentally Friendly and Sustainable Bioproduction of Aminobenzoic Acid and Its Derivatives

“…The most stable form of these vitamins is fully oxidized pteroylglutamic acid (PteGlu). Due to the different oxidation states within the pterin ring, different 1C-units connected at positions N 5 and/or N 10 (typically 1C-units in the form of methyl (CH 3 -), formyl (HCO-), or methenyl (-CH + -) groups), and changes in the length of the glutamyl tail, a large number of different forms of folates are produced [46] (Figure 2). Many physiological processes, such as the biosynthesis of purine and thymidine monophosphate, the regeneration of methionine and the translation of mitochondrial protein, require folate for 1C-unit transfer [61].…”

“…The cooverexpression of folC, pabB, folE, and yciA enhanced the supply of 5-MTHF precursors and inhibited the pheA gene, successfully increasing the titer of 5-MTHF to 1.58 mg/L. Schillert et al [46] applied the molecular network to the folate metabolism of yeast. After 20 h of culture, the folate content reached the highest, which was 131.2 mg/L.…”