Molecular and Phenotypic Diversity of Indigenous Oenological Strains of Saccharomyces cerevisiae Isolated in Greece

During 3 years, we explored the biodiversity of the indigenous yeast flora in five Greek wine regions by collecting five varietal grape samples, conventionally and biologically cultured. Spontaneous wine fermentations were carried out by the native microbiota of the grape juice, without the inoculation of selected industrially produced yeast. The indigenous yeast flora, isolated at three phases of these fermentations, was purified and characterized using different oenological and technological criteria. The pre-selected Saccharomyces cerevisiae strains, with the most promising oenological characteristics, were evaluated in microvinifications of Malagousia must and the quality of the produced wines was subjected to a sensorial descriptive analysis.

Prospects of studies on the yeast flora of sturgeons for monitoring of their state in aquaculture

Seasonal changes in abundance and species composition of the yeast flora from organs of juvenile sturgeons were traced during their growing in the warm-water ponds of Luchegorsk Research Station of the Pacific Fish. Res. Centre (TINRO) in 2008-2009. The fungal community of the sturgeons was represented by whey, brewers, and wine yeasts, mostly with probiotic properties. Naganishia albida, Papiliotrema laurentii, Saccharomyces cerevisiae, Trichomonascus ciferrii , and fungi of the genus Candida were found in the intestines and gills of kaluga and siberian sturgeon juveniles, but they came from the water and are usual for microflora of cages for fish cultivation. Cryptococcus neoformans and Ogataea angusta were found in the water only. Rhodotorula mucilaginosa , Cystobasidium minuta and fungi of the genus Hanseniaspora were associated with the sturgeon organs. Generally the yeast heterotrophic microbiota in the cages showed inhibitory effect against mould and enterobacteria. Colonization of the sturgeon mucous membranes by yeasts had seasonal dynamics that definitely affected on local immunity of the juveniles. Complete elimination of the yeasts from the sturgeon mucous membranes should be considered as a predictor of worsening of their physiological state and anti-epizootic measures are necessary in this case.