Abstract
Human-associated microorganisms are ideal models to study the impact of
environmental changes on species evolution and adaptation. The yeast
Brettanomyces bruxellensis is a good example of organism facing
anthropogenic-driven selective pressures. It is associated with
fermentation processes in which it can be considered either as a spoiler
(e.g. winemaking, bioethanol production) or as a beneficial
microorganism (e.g. production of specific beers, kombucha). Besides its
industrial interests, noteworthy parallels and dichotomies with
Saccharomyces cerevisiae propelled B. bruxellensis as a valuable
complementary yeast model. In this review, we emphasize that the broad
genetic and phenotypic diversity of this species is only beginning to be
revealed. Population genomic studies have revealed the co-existence of
auto- and allotriploidization events with different evolutionary
outcomes. The various diploid, autotriploid and allotriploid
subpopulations are associated with specific fermented processes,
suggesting independent adaptation phenomena to anthropized environments.
Phenotypically, B. bruxellensis is renowned for its ability to
metabolize a wide variety of carbon and nitrogen sources, which may
explain its ability to colonize already fermented environments showing
low-nutrient contents. Several traits of interest could be related to
adaptation to human activities (e.g. nitrate metabolization in
bioethanol production, resistance to sulphite treatments in winemaking).
However, phenotypic traits are insufficiently studied in view of the
great genomic diversity of the species. Future work will have to take
into account strains of varied substrates, geographical origins as well
as displaying different ploidy levels. Finally, we discuss the
characteristics of B. bruxellensis which may prove to be of wider
interest in future research.