Characterization of yeast communities vectored by Drosophila melanogaster during post-harvest fermentation of coffee

Drosophila melanogaster, present in coffee processing stages, feeds on mucilage and coffee “cherries”, inoculating yeasts that influence coffee bean fermentation. This pioneering study in Colombia evaluated the microorganisms associated with the larvae of this fly, determining their kinetic behavior, observing their morphophysiological structures, and characterizing the types of yeasts present. Understanding the interaction between these microorganisms and coffee bean quality is crucial in the coffee industry, given that in other industries, such as winemaking, they have been shown to directly affect the organoleptic characteristics of the final product. This study was carried out in three coffee-growing municipalities in northern Nariño. The yeasts present in the oral apparatus of D. melanogaster larvae were analyzed. These were cultivated in YGC media differentiated by color and growth type. Quantification was performed using colony forming units (CFUs) and lactophenol blue staining. Additionally, the number of CFUs was correlated with spectrophotometric measurements. The results revealed the presence of yeast species such as Geotrichum, Galactomyces, Trichosporon, and Blastoschizomyces. This research provides an approximation to the microbiome of coffee-growing environments and its biotechnological potential. Moreover, it lays the foundation to formulate methodologies for the morphophysiological classification of yeast strains associated with insects, their role in coffee fermentation processes, and their potential to determine flavor and quality of the final product.