Characterization of maltotriose transporters from theSaccharomyces eubayanussubgenome of the hybridSaccharomyces pastorianuslager brewing yeast strain Weihenstephan 34/70

Abstract

Significance and Impact of Study: The Saccharomyces pastorianus lager yeast usually ferments maltose and maltotriose efficiently, and transport of these a-glucosides into the brewer's yeast cell is thought to be rate limiting in the fermentation of these sugars from wort. Our results revealed a new maltotriose transporter gene in the Saccharomyces eubayanus subgenome of the industrial lager brewing strain Weihenstephan 34/70 that allows efficient maltotriose fermentation by yeast cells. The characterization of maltotriose transporters from industrial yeasts opens new opportunities to increase yeast fitness for fermentation of brewer's wort, preventing incomplete or sluggish maltotriose fermentations. AbstractThe genome from the Saccharomyces pastorianus industrial lager brewing strain Weihenstephan 34/70, a natural Saccharomyces cerevisiae/Saccharomyces eubayanus hybrid, indicated the presence of two different maltotriose transporter genes: a new gene in the S. eubayanus subgenome with 81% of homology to the AGT1 permease from S. cerevisiae, and an amplification of the S. eubayanus MTY1 maltotriose permease previously identified in S. pastorianus yeasts. To characterize these S. eubayanus transporter genes, we used a S. cerevisiae strain deleted in the AGT1 permease and introduced the desired permease gene(s) into this locus through homologous recombination. Our results indicate that both the MTY1 and AGT1 genes from the S. eubayanus subgenome encode functional maltotriose transporters that allow fermentation of this sugar by yeast cells, despite their apparent differences in the kinetics of maltotriose-H + symport activity. The presence of two maltotriose transporters in the S. eubayanus subgenome not only highlights the importance of sugar transport for efficient maltotriose utilization by industrial yeasts, but these new genes can be used in breeding and/or selection programs aimed at increasing yeast fitness for the efficient fermentation of brewer's wort.

The microbial diversity of an industrially produced lambic beer shares members of a traditionally produced one and reveals a core microbiota for lambic beer fermentation

“…The latter was characterized by the presence of Saccharomyces spp., which were isolated in batch A until the third month. The ratio of S. pastorianus to S. cerevisiae increased for a reason that is not known but may be related to fermentation temperature adaptation (Cousseau et al, 2013;Vidgren et al, 2010). The latter phenomenon was also seen during a traditional lambic beer fermentation studied previously (Spitaels et al, 2014c).…”

Phylogeography of the wild Lager‐brewing ancestor (Saccharomyces eubayanus) in Patagonia

“…Similar results were obtained by other authors (Hebly et al ., ; Magalhães et al ., ). In Lager yeasts (and some Ale strains), maltotriose assimilation occurs due to the presence of genes encoding permeases, including MTT1 and AGT1, which were thought to come from the S. eubayanus parental strain (Cousseau et al ., ). However, none of the available S. eubayanus genomes contain MTT1 , although deposited reads contain sequences closely related to AGT1 (Baker et al ., ; Magalhães et al ., ; Peris et al ., ).…”

The effect of β-glucan and its potential analog on the structure of Dectin-1 receptor

“…In this study, MT, has been chosen as an potential analog on the basis of 95% of structural similarity, retrieved by similarity search for corresponding ligand from the PubChem library and validated through Zinc15 [24][25][26], indicating that they are all specific to the ligands family. Both the complexes were subjected for detailing the Recently, the maltotriose transporters have been studied in various fungus species [27,29].…”