Assessment of the fungal community associated with cocoa bean fermentation from two regions in Colombia

Abstract

The quality of the cocoa seeds depends on various factors. Fermentation is among them because during this process flavor precursors are synthesized through the action of fungi and bacteria, whose diversity can change depending on the geographic location and the agricultural practices. This research aimed to characterize and compare the fungal community involved in spontaneous fermentations carried out under the same post-harvest agricultural practices in two farms located at completely different agro‑ecological zones by application of a high-throughput amplicon sequencing method. The results showed that the diversity of biological variants is different between regions. In the Magdalena Medio region, the fermentations were dominated by Hanseniaspora opuntiae, and Saccharomyces sp., while in Urabá region all the fermentation was characterized by an almost constant diversity and high abundance of H. opuntiae. In each site, unique biological variants of these two genera were detected. Additionally, differences were observed in the physicochemical parameters such as the pH and temperature of the fermentation mass, and the duration of the process. The analyses of these results allow concluding that the environmental conditions and indigenous microbiota of each cocoa-cultivation zone explained the differences found in this study.