Identification of yeasts during alcoholic fermentation of tchapalo, a traditional sorghum beer from Côte d’Ivoire

Abstract

This study investigated the diversity and dynamics of yeasts involved in alcoholic fermentation of a traditional sorghum beer from Côte d'Ivoire, tchapalo. A total of 240 yeast strains were isolated from fermenting sorghum wort inoculated with dry yeast from two geographic regions of Côte d'Ivoire (Abidjan and Bondoukou). Initial molecular identification to the species level was carried out using RFLP of PCR-amplified internal transcribed spacers of rDNA (ITS1-5.8S-ITS2). Ten different profiles were obtained from the restriction of PCR products with the three endonucleases HaeIII, CfoI and HinfI. Sequence analysis of the D1/D2 domain of the 26S rDNA and the ACT1 gene allowed us to assign these groups to six different species: Saccharomyces cerevisiae-like, Candida tropicalis, Pichia kudriavzevii, Pichia kluyveri, Kodamaea ohmeri and Meyerozyma caribbica. The most frequent species associated with tchapalo fermentation was S. cerevisiae-like (87.36%), followed by C. tropicalis (5.45%) and M. caribbica (2.71%). S. cerevisiae-like strains were diploid heterozygotes and exhibited three to four nucleotides divergence from the type strain in the D1/D2 domain and several indels in the more discriminant sequence of the intron of the ACT1 gene. During the process, the yeast species isolated and their frequencies varied according to the geographic origin of the dry yeast. The occurrence of some species was sporadic and only two non-Saccharomyces species were found in the final product.

The Microbiology of Malting and Brewing

“…These include such popular libations as ikigage of Rwanda (259), bili bili of Chad (260), tchoukoutou of Benin (261), tchapalo of Côte d'Ivoire (262), pito in Ghana, Togo, and Nigeria, and dolo in Burkina Faso (263). These beers are made from malted sorghum, and often malted millet, and otherwise involve roughly similar brewing processes consisting of a sour mash followed by alcoholic fermentation.…”

Influence of Freeze-Dried Yeast Starter Cultures on Volatile Compounds of Tchapalo, a Traditional Sorghum Beer from Côte d’Ivoire

“…They were isolated from traditional sorghum beer from the district of Abidjan (Southern Côte d'Ivoire). They were identified by Polymerase Chain Reaction-Restriction Fragment Length polymorphism (PCR-RFLP) of the Internal Transcribed Spacer (ITS) region and sequencing of D1/D2 domains of the 26S rRNA gene [6]. The yeast strains were maintained routinely at −20 • C in 20% glycerol.…”

“…During the brewing of sorghum beer, the alcoholic fermentation stage is performed by several yeast strains, among which Saccharomyces cerevisiae was the predominant strain [3][4][5][6]. Among the non-Saccharomyces yeasts, the predominant species varied according to geographic origin of the beer.…”

Biochemical and Microbiological Changes during the Ivorian Sorghum Beer Deterioration at Different Storage Temperatures

“…plantarum, and Lb. hilgardii, which is associated with Enterococcus, Pediococcus, and Leuconostoc [17,18]. The final beverage has a short shelf life and undergoes rapid deterioration within one to four days of production like most traditional African fermented foods.…”