Yeasts with Fermentative Potential Associated with Fruits of Camu-Camu (Myrciaria Dubia, Kunth) from North of Brazilian Amazon

Abstract PurposeConsidering the high biotechnological potential of yeasts associated to edible fruits, a screening for these microbes able to alcoholic fermentation was performed in ripe fruits of camu-camu.MethodsFruits of camu-camu (Myrciaria dubia, Kunth) were collected in north of brazilian Amazon, in floodplain of Cauamé river. Yeasts were isolated, and fermentation capability was evaluated using Durham tubes. Quantitative assays were performed to calculate ethanol yield (g.g–1), specific growth rate (h–1) and ethanol productivity (g.L–1.h–1). Taxonomic identification was performed by ribosomal genes nucleotides sequences analysis by alignment using BLASTn.ResultsA total of fifteen yeasts colonies were isolated, and eight of them presented the ability to ferment glucose to ethanol. Six of them were identified as three different species: Candida orthopsilosis, Pichia kudriavzevii and Meyerozyma caribbica. When cultured in broth containing 180 g.L–1 of glucose, M. caribbica reaches 91.7 percent of the maximum theoretical ethanol concentration (84.4 g.L–1), presenting ethanol yield and productivity of 0.4688 g.g–1 and 0.781 g.L–1.h–1, respectively.ConclusionsThe endophytic microbiota of camu-camu includes C. orthopsilosis, P. kudriavzevii and M. caribbica. This paper is a rare report of C. orthopsilosis with endophytic habit, because most of the references indicate it as human pathogenic. Besides this, M. caribbica is a promising fermenter for alcoholic beverages, due to its osmotolerance and high ethanol yield. This is the first paper reporting endophytic yeasts associated with fruits of Myrciaria dubia.