Identification of yeasts isolated from raffia wine (Raphia hookeri) produced in Côte d'Ivoire and genotyping of Saccharomyces cerevisiae strains by PCR inter-delta.

Abstract

Raffia wine is a traditional alcoholic beverage produced in several African countries where it plays a significant role in traditional customs and population diet. Alcoholic fermentation of this beverage is ensured by a complex natural yeast flora which plays a decisive role in the quality of the final product. This present study aims to evaluate the distribution and the diversity of the yeast strains isolated in raffia wine from four sampling areas (Abengourou, Alépé, Grand-Lahou and Adzopé) in Côte d'Ivoire. Based on the D1/D2 domain of the LSU rDNA sequence analysis, nine species belonging to six genera were distinguished. With a percentage of 69.5% out of 171 yeast isolates, Saccharomyces cerevisiae was the predominant species in the raffia wine, followed by Kodamaea ohmeri (20.4%). The other species isolated were Candida haemulonii (4.1%), Candida phangngensis (1.8%), Pichia kudriavzevii (1.2%), Hanseniaspora jakobsenii (1.2%), Candida silvae (0.6%), Hanseniaspora guilliermondii (0.6%) and Meyerozyma caribbica (0.6%). The molecular characterization of S. cerevisiae isolates at the strain level using the PCR-interdelta method revealed the presence of 21 profiles (named I to XXI) within 115 isolates. Only four profiles (I, III, V and XI) were shared by the four areas under study. Phenotypic characterization of K. ohmeri strains showed two subgroups for sugar fermentation and no diversity for the nitrogen compound assimilations and the growth at different temperatures.