Prospective Yeast Species with Enzymatic, Aromatic, and Antifungal Applications Isolated from Cocoa Fermentation in Various Producing Areas in Côte d’Ivoire

This research study investigated the potential biotechnological applications of yeast species obtained from cocoa fermentation performed in Côte d’Ivoire. A total of 279 yeast isolates were molecularly identified and then screened for their antifungal ability against various Aspergillus species and for the production of aromatic compounds and extracellular enzymes. Thirty-one yeast species belonging to nineteen genera, dominated by Pichia, Candida, Hanseniaspora, and Rhodotorula, were isolated from fermented cocoa beans. All extracellular enzymes screened were produced by most yeast species, except β-glucanase and esterase activity, whereas the most common enzyme was β-glucosidase. Yeasts of the Pichia, Saccharomyces, Candida, Clavispora, and Hanseniaspora genera produced various enzymes, including xylanase, β-glucosidase, polygalacturonase, invertase, pectinase, and chitinase. The 88 aromatic compounds produced were grouped into five main chemical families, including esters, alcohols, acids, aldehydes, and ketones. Wickerhamomyces anomalus was the highest producer of major desirable aromatic compounds, including alcohols, ketones, and esters. All yeast species showed a specific antagonistic effect against the growth of various Aspergillus species, but Candida incommunis, Saccharomyces cerevisiae, and Torulaspora delbrueckii recorded the greatest antifungal ability. These yeast species could be used to develop promising starter cultures to improve the organoleptic quality of various fermented foods and beverages.