## 3 Results and Discussion
### Microbiota Dynamics during Inoculated Coffee Fermentation  
To improve the quality and complexity of fermented beverages, co-inoculation of LAB and yeast has been widely employed in the wine industry and more recently in coffee fermentations [10; 33; 34]. However, the starter cultures used in these processes must be able to suppress the growth of wild microbiota. The results reported in this study showed that co-inoculation favored the growth of the starter cultures (Figure 4). _Pichia_ showed a population over 70% throughout the fermentative process. The family Lactobacillusaeae, which includes _Pediococcus_, was also dominant at the beginning of the fermentative process (45.13%) followed by Enterobacteriaceae (23.85%) and _Lactococcus_ (10.11%). After 8 h, the OTU readings attributed to Lactobacillusaee increased to 59.38%, suppressing the growth of Enterobacteriaceae (0.45%) and other species. At the end of the process, the reading of Lactobacillusaee increased to 77.40% (Figure 4). The predominance of _P. fermentans_ YC5.2 over the wild microbiota is mainly associated with the metabolic versatility of this yeast in tolerating osmotic pressure (growth detected with up to 50% glucose and fructose), ability to grow over a wide pH range (pH 2.0-8.0), growth at temperatures ranging from 30 to 43 \({}^{\circ}\)C, and tolerance to the main metabolites (ethanol, lactic acid and acetic acid) produced in the course of the fermentation [13]. Recently, analysis of the _P. acidilactici_ LPBC161 genome performed by [PERSON] et al. [19] showed that its high fermentative capacity can be explained by the presence of several genes involved in the metabolism of sugars present in the coffee pulp, in addition to genes encoding proteins related to oxidative and alkaline stress. [PERSON] et al. [18] also demonstrated that there is a positive synergistic interaction between LAB and yeast. The possible hypotheses to explain these interactions are (i) yeast autolysis releases nutrients, such as polysaccharides, riboflavin, and amino acids, favorable for bacterial growth and (ii) acidification of the fermentation medium by LAB creates a favorable environment for yeast development. Enabling the development and co-dominance of these two species. Although LAB and yeast are the main microbial groups involved in coffee fermentations, the dominance of both these microbial groups may not be observed during spontaneous process. For instance, codominance of AAB (_Gluconobacter_ and _Acetobacter_), LAB (_Leuconstoc_ and _Lactococcus_), yeasts (_Hanseniagpora, Candida_, and _Pichia_) and the filamentous fungus _Fusarium_ was recently observed in a spontaneous fermentation conducted in Honduras [10]. The microbial dynamics of another spontaneous fermentation conducted in Australia also showed some peculiarities. Although LAB increased during the fermentation process, it was noted that the population of Enterobacteriaceae and other subdominant microbial groups remained high after 36 h of fermentation [14]. Thus, the use of starter cultures is seen as essential to ensure the growth of beneficial microorganisms (i.e., yeast and LAB) during coffee fermentation. Interestingly, during the entire fermentation process, a total of 135 and 115 prokaryotic and eukaryotic groups were identified, respectively (Table S2). The fermentation started with only 86 prokaryotes and 45 eukaryotes. It was noted that some species (e.g., _Trichococcus_, _Terriglobus_, _Fusobacterium_, _Passalora_ and _Lecanosticta_) were not associated with the farm microbiome, suggesting that these microorganisms may have been introduced into the fermentation by human contact. In addition, several microbial genera (e.g., _Penicillium_, _Malasezia_, _Debaryomyces_, _Enterobacter_, _Pseudomonas_ and _Kaistolacter_), associated with farm microbiome, were detected only 8 h after the start of the fermentation process. Besides human contact, one of the contamination routes is likely to air since the coffee fermentations are carried out in open tanks.