Yeasts and yeast-like organisms isolated from fish-pond waters.

Fifteen genera and 29 yeast species were found in the water of three fish-ponds located in the area of the Lowland Zahorie (Slovakia). The fish-ponds were sampled in summer and autumn. Aureobasidium, Sporobolomyces, Candida, and Cryptococcus species occurred the most frequently. The composition of yeast species was more heterogeneous in summer than in autumn, but the number of yeasts observed in autumn was 5.5 times higher than those isolated in summer. Some species of the genus Candida, Hyphopichia burtonii, Aureobasidium pullulans, Hansenula anomala and Cryptococcus laurentii were frequently isolated in summer in high counts. The occurrence of the "black yeasts" A. pullulans increased in autumn and together with red yeasts Sporobolomyces roseus represented approximately 70% of the yeast population.