New Lager Brewery Strains Obtained by Crossing Techniques Using Cachaça (Brazilian Spirit) Yeasts

• Published in: Applied and environmental microbiology Vol. 83; no. 20
• Main Authors: Figueiredo, Bruna Inez Carvalho, Saraiva, Margarete Alice Fontes, de Souza Pimenta, Paloma Patrick, de Souza Testasicca, Miriam Conceição, Sampaio, Geraldo Magela Santos, da Cunha, Aureliano Claret, Afonso, Luis Carlos Crocco, Vieira de Queiroz, Marisa, de Miranda Castro, Ieso, Brandão, Rogelio Lopes
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 15-10-2017
• Subjects: Acetic acid; Beer; Breweries; Distilleries; Esters; Fermentation; Flocculation; Food Microbiology; Genetically modified organisms; Hybrids; Lager; Low temperature; Reproductive cycle; Sporulation; Spotlight; Viability; Yeast; Yeasts; hybrid; mating type; flocculation; aroma volatile compounds; beer
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.01582-17

The development of hybrids has been an effective approach to generate novel yeast strains with optimal technological profile for use in beer production. This study describes the generation of a new yeast strain for lager beer production by direct mating between two
strains isolated from
distilleries: one that was strongly flocculent, and the other with higher production of acetate esters. The first step in this procedure was to analyze the sporulation ability and reproductive cycle of strains belonging to a specific collection of yeasts isolated from
fermentation vats. Most strains showed high rates of sporulation, spore viability, and homothallic behavior. In order to obtain new yeast strains with desirable properties useful for lager beer production, we compare haploid-to-haploid and diploid-to-diploid mating procedures. Moreover, an assessment of parental phenotype traits showed that the segregant diploid C2-1d generated from a diploid-to-diploid mating experiment showed good fermentation performance at low temperature, high flocculation capacity, and desirable production of acetate esters that was significantly better than that of one type lager strain. Therefore, strain C2-1d might be an important candidate for the production of lager beer, with distinct fruit traces and originating using a non-genetically modified organism (GMO) approach.
Recent work has suggested the utilization of hybridization techniques for the generation of novel non-genetically modified brewing yeast strains with combined properties not commonly found in a unique yeast strain. We have observed remarkable traits, especially low temperature tolerance, maltotriose utilization, flocculation ability, and production of volatile aroma compounds, among a collection of
strains isolated from
distilleries, which allow their utilization in the production of beer. The significance of our research is in the use of breeding/hybridization techniques to generate yeast strains that would be appropriate for producing new lager beers by exploring the capacity of
yeast strains to flocculate and to ferment maltose at low temperature, with the concomitant production of flavoring compounds.