title: Breeding Strategy To Generate Robust Yeast Starter Cultures for Cocoa Pulp Fermentations.
abstract: Cocoa pulp fermentation is a spontaneous process during which the natural microbiota present at cocoa farms is allowed to ferment the pulp surrounding cocoa beans. Because such spontaneous fermentations are inconsistent and contribute to product variability, there is growing interest in a microbial starter culture that could be used to inoculate cocoa pulp fermentations. Previous studies have revealed that many different fungi are recovered from different batches of spontaneous cocoa pulp fermentations, whereas the variation in the prokaryotic microbiome is much more limited. In this study, therefore, we aimed to develop a suitable yeast starter culture that is able to outcompete wild contaminants and consistently produce high-quality chocolate. Starting from specifically selected Saccharomyces cerevisiae strains, we developed robust hybrids with characteristics that allow them to efficiently ferment cocoa pulp, including improved temperature tolerance and fermentation capacity. We conducted several laboratory and field trials to show that these new hybrids often outperform their parental strains and are able to dominate spontaneous pilot scale fermentations, which results in much more consistent microbial profiles. Moreover, analysis of the resulting chocolate showed that some of the cocoa batches that were fermented with specific starter cultures yielded superior chocolate. Taken together, these results describe the development of robust yeast starter cultures for cocoa pulp fermentations that can contribute to improving the consistency and quality of commercial chocolate production.
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium.
authors.forename: Esther
authors.initials: E
authors.lastname: Meersman
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Steensels
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium.
authors.forename: Tinneke
authors.initials: T
authors.lastname: Paulus
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium.
authors.forename: Nore
authors.initials: N
authors.lastname: Struyf
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium.
authors.forename: Veerle
authors.initials: V
authors.lastname: Saels
authors.affiliation: Barry Callebaut AG, Zurich, Switzerland.
authors.forename: Melissa
authors.initials: M
authors.lastname: Mathawan
authors.affiliation: Barry Callebaut AG, Zurich, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Koffi
authors.affiliation: Barry Callebaut AG, Zurich, Switzerland.
authors.forename: Gino
authors.initials: G
authors.lastname: Vrancken
authors.affiliation: Laboratory for Genetics and Genomics, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium Laboratory for Systems Biology, VIB, Leuven, Belgium kevin.verstrepen@biw.vib-kuleuven.be.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Verstrepen
mesh_terms: D002099:Cacao / Q000378:metabolism*; D005285:Fermentation; D006358:Hot Temperature; D006824:Hybridization, Genetic; D007218:Industrial Microbiology / Q000379:methods*; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology