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

Abstract

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.

Keywords

• осетровые рыбы
• дрожжевая флора
• мониторинг