Characterization of yeast diversity colonizing various olive habitats associated to Moroccan Picholine olive variety (orchards and crushing units)

Morocco has an extremely geomorphological, topographical and bioclimatic diversity; hence the origin of the diversity of ecosystems. The aim of this study was to know the yeast diversity from Olea europaea at two Moroccan olive habitats, orchards and crushing unit of Moroccan Picholine olive variety. This study focused on two different locations from Marrakech-Safi region in Morocco: Elkalaa Des Sraghna and Essaouira. From each location, the samplings were collected from three orchards of olive trees, characterized by a diversity of soil (nature, texture and salinity) and three crushing units. The samples are drawn in each orchard from soil under trees, leaves and olive fruits. Co- products e.g olives stored before crushing, olive mill wastewater, olive oil and pomace were collected in crushing units. Stock solutions and dilutions from each sample were prepared and cultured on YM agar medium at 30 °C. 109 isolates of yeasts have been found from Elkalaa Des Sraghna habitats and 76 yeasts from Essaouira habitats of which 75 vs. 40 isolates are found in orchards habitats and 34 vs. 36 isolates associated with the crushing units habitats from Elkalaa Des Sraghna and Essaouira habitats respectively. The morphological and physiological studies of these isolates identified several yeast species, potentially candidate in Biotechnology and belonging to the genera Debaryomyces, Saccharomyces, Candida, Cryptococcus, Rhodotorula and Pichia.