CMO1 encodes a putative choline monooxygenase and is required for the utilization of choline as the sole nitrogen source in the yeast Scheffersomyces stipitis (syn. Pichia stipitis)

Abstract

CMO1 encodes a putative choline monooxygenase and is required for the utilization of choline as the sole nitrogen source in the yeast Scheffersomyces stipitis (syn. Pichia stipitis) Sixteen yeasts with sequenced genomes belonging to the ascomycete subphyla Saccharomycotina and Taphrinomycotina were assayed for their ability to utilize a variety of primary, secondary, tertiary and quartenary aliphatic amines as nitrogen sources. The results support a previously proposed pathway of quaternary amine catabolism whereby glycine betaine is first converted into choline, which is then cleaved to release trimethylamine, followed by stepwise demethylation of trimethylamine to release free ammonia. There were only a few instances of utilization of N-methylated glycine species (sarcosine and N,N-dimethylglycine), which suggests that this pathway is not intact in any of the species tested. The ability to utilize choline as a sole nitrogen source correlated strongly with the presence of a putative Rieske nonhaem iron protein homologous to bacterial ring-hydroxylating oxygenases and plant choline monooxygenases. Deletion of the gene encoding the Rieske non-haem iron protein in the yeast Scheffersomyces stipitis abolished its ability to utilize choline as the sole nitrogen source, but did not affect its ability to use methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, ethanolamine or glycine as nitrogen sources. The gene was named CMO1 for putative choline monooxygenase 1. A bioinformatic survey of eukaryotic genomes showed that CMO1 homologues are found throughout the eukaryotic domain.

Biological oxidation of choline‐based ionic liquids in sequencing batch reactors

“…As can be seen in Fig. , the first step of the degradation process is the formation of various amines (tri‐, di‐ and methylamine) and ethanol, which is consistent with previous reports . Then, the microbial community efficiently degrades these compounds to CO 2 , H 2 O, nitrite and nitrate as end‐products.…”

“…5, the first step of the degradation process is the formation of various amines (tri-, di-and methylamine) and ethanol, which is consistent with previous reports. 34,74,75 Then, the microbial community efficiently degrades these compounds to CO 2 , H 2 O, nitrite and nitrate as end-products. Intermediates from glucose degradation including xylulose, acetylphosphate and ethanol also were detected in the medium.…”

“…The choline cation, N , N , N ‐trimethylethanolammonium, is an essential nutrient posted as vitamin B to humans . Betaine is a metabolite of choline presents at high levels in the liver and the kidney, and acetylcholine is involved in memory functions and muscle control .…”

“…The choline cation, N,N,N-trimethylethanolammonium, is an essential nutrient posted as vitamin B to humans. 33,34 Betaine is a metabolite of choline presents at high levels in the liver and the kidney, 35 and acetylcholine is involved in memory functions and muscle control. 36 In recent years, choline-based ILs have been widely studied on account of their potential uses for organic synthesis, 37 biomass conversion, 38 gas absorption, 39 polymerization, 40 metal extraction 41 and lubrication.…”

Pan-genome-scale network reconstruction: a framework to increase the quantity and quality of metabolic network reconstructions throughout the tree of life

“…Our pan-GENRE has a wider metabolic coverage than prior yeast and fungal GENRE's. The pan-GENRE includes the degradation of alkanes and 4/19 aromatics, which have been studied in Fungi for decades (Middelhoven et al, 1991(Middelhoven et al, , 1992Van Beilen and Funhoff, 2007), and the degradation of aliphatic amines, which has been recently studied in S. stipitis by Linder (2014Linder ( , 2018. These pathways are mediated by hydroxylases, monooxygenases, and dioxygenases from the cytochrome P450's family, which do not have well described gene-protein-reaction associations in current reaction databases.…”