Fermentative Potential of Yeasts Isolated from the Fruits of the African Ebony Tree (Diospyros mespiliformis) in Côte d'Ivoire for Bioethanol Production

This study, which aims to contribute to the valorization of Diospyros mespiliformis fruits, was conducted at the laboratory of Peleforo GON COULIBALY University in Korhogo (Ivory Coast). It aimed, on the one hand, to analyze some physicochemical parameters (moisture content, dry matter, total soluble solids, pH, titrable acidity, and vitamin C content) of Diospyros mespiliformis pulp and, on the other hand, to select potential yeast starters for bioethanol production. Thus, the microbiological analyses of the pulp consisted of testing their fermentative capacity, then subjecting the isolates with high fermentative capacity to the influence of some fermentative parameters (sodium chloride, glucose, and ethanol) on their growth. Physico-chemical parameters revealed that the pulp of Diospyros mespiliformis has a high moisture content (74.97%), an acidic pH of 3.85, a titrable acidity of 1.41%, a vitamin C content of 12.35 mg/100 g, and a soluble dry extract of 5 °B. All these characteristics make the fruits of Diospyros mespiliformis an interesting source of nutrients. Furthermore, microbiological analyses allowed for the isolation and identification of eighty-six (86) yeasts based on their macroscopic and microscopic characteristics. Among these isolates, six showed a strong fermentative capacity and exhibited good microbial growth under the influence of the studied fermentative parameters. Thus, these six (6) isolates could be proposed as potential starters in biotechnological applications to standardize and control certain fermentation processes such as bioethanol production.