Saccharomyces arboricola and Its Hybrids’ Propensity for Sake Production: Interspecific Hybrids Reveal Increased Fermentation Abilities and a Mosaic Metabolic Profile

Abstract

The use of interspecific hybrids during the industrial fermentation process has been well established, positioning the frontier of advancement in brewing to capitalize on the potential of Saccharomyces hybridization. Interspecific yeast hybrids used in modern monoculture inoculations benefit from a wide range of volatile metabolites that broaden the organoleptic complexity. This is the first report of sake brewing by Saccharomyces arboricola and its hybrids. S. arboricola x S. cerevisiae direct-mating generated cryotolerant interspecific hybrids which increased yields of ethanol and ethyl hexanoate compared to parental strains, important flavor attributes of fine Japanese ginjo sake rice wine. Hierarchical clustering heatmapping with principal component analysis for metabolic profiling was used in finding low levels of endogenous amino/organic acids clustered S. arboricola apart from the S. cerevisiae industrial strains. In sake fermentations, hybrid strains showed a mosaic profile of parental strains, while metabolic analysis suggested S. arboricola had a lower amino acid net uptake than S. cerevisiae. Additionally, this research found an increase in ethanolic fermentation from pyruvate and increased sulfur metabolism. Together, these results suggest S. arboricola is poised for in-depth metabolomic exploration in sake fermentation.

Unique Brewing-Relevant Properties of a Strain of Saccharomyces jurei Isolated From Ash (Fraxinus excelsior)

“…Indirect applications have involved the creation of interspecies hybrids and assessment of the performance of these hybrids in fermentation processes. Examples have included the use of S. cerevisiae × S. arboricola , S. cerevisiae × S. eubayanus , S. cerevisiae × S. kudriavzevii , and S. cerevisiae × S. mikatae hybrids in beverage fementations and for bioethanol production ( Krogerus et al, 2017 ; Peris et al, 2017 ; Winans et al, 2020 ). Unaltered strains and interspecies hybrids of S. jurei , along with other Saccharomyces hybrids, have also been investigated for their baking potential in dough fermentation ( Magalhães et al, 2021 ).…”

Yeast Hybrids in Brewing

“…Hybrid yeast development has been carried out for over half a century aimed predominantly at increasing attenuation and fermentation rates via intraspecific crosses with ale and lab strains [38][39][40]. Modern fermentations benefit from many innate and acquired hybrids that have been isolated or developed [17,27,[41][42][43][44][45][46][47][48][49][50][51][52][53]. Early efforts in brewing science established the fundamentals necessary to explore the phylogeny, genomics, and strain development for Saccharomyces fermentation.…”

Yeast Hybrids in Brewing

“…Hybrid yeast development has been carried out for over half a century since then, aimed predominantly at increasing attenuation and fermentation rates via intraspecific crosses with ale and lab strains [38][39][40]. Modern fermentations benefit from many innate and acquired hybrids that have been isolated or developed [11,27,28,[41][42][43][44][45][46][47][48][49][50][51][52]. Early efforts in brewing science established the fundamentals necessary to explore the phylogeny, genomics, and strain development for Saccharomyces fermentation.…”