Mapping the functional and strain diversity of the main microbiota involved in cocoa fermentation from Cote d’Ivoire

The variable quality of cocoa produced by farmers is still a problem in the value chain, strongly depending on microbial activities. We analyzed the variability of cocoa microbiota from all twelve producing regions in Cote d’Ivoire, and described the geographical distribution of isolated microbiota, using a mapping. Microbial species were identified by ribosomal genes sequencing, strains were typed by RFLP and their techno-functional capacities were further investigated. Results showed a restricted diversity of lactic acid bacteria (LAB) and acetic acid bacteria (AAB) with respectively 10 and 5 strains. The dominant LAB and AAB strains, notably Lactobacillus plantarum 1 A, Acetobacter pasteurianus 1 A, Acetobacter okinawensis 2 A, and Acetobacter tropicalis 3 A, were found in all regions assuming that the acid microbiota was weakly variable. In contrast, the distribution of their functional performance such as acidification capability was variable, stronger in strains from Nawa and Haut-Sassandra regions and weaker in Indenie-Djuablin and San Pedro; this distribution seemed to be random. Moreover, the study also revealed a complex yeasts population showing a wide genetic diversity with 22 species and 45 strains indicating an intraspecific heterogeneity. Strains were generally different from a region to another and the resulting yeasts microbiota was globally variable in the regions. Likewise, the functional capacities such as pectinolytic was weak in P. kudriazevii strain 2 K from Gboklè and strong in P. kudriazevii strain 2 A from Loh-Djiboua. Additionally, the quality of fermented beans was also variable in the regions. The great variation of yeasts strains in the different regions may be the main microbial factors responsible for variation of the fermented cocoa quality observed. •Yeasts strains were different from a region to another region, possible factor of cocoa quality variation.•The same strains of lactic acid bacteria and acetic acid bacteria were generally found in all the regions.•Acidification capacity with high potential of aroma was stronger in strains from Nawa and Haut-Sassandra.•Peak of temperature was the more varying parameter in cocoa fermentation from all regions.•Resemblance of the spontaneous dominant strains and cocoa quality were not necessary linked.