Yeasts in the rumen contents of musk oxen

The yeast flora of 16 samples of rumen contents of musk oxen (ovibos moschatus) from East Greenland was examined. Variable numbers of yeast colonies developed on agar plates incubated at 25 degrees C, the counts being up to 136000 per g (wet wt). Of the 41 strains isolated, the majority belonged to Candida and Cryptococcus; others were species of Trichosporon, Rhodotorula, Torulopsis and Pichia. Very few colonies appeared on plates incubated at 37 degrees C, and only one species of Candida was isolated. Samples of rumen contents kept at about 5 degrees C for about 3 years contained a much greater number of yeasts, up to several million per g (wet wt) being counted on agar plates incubated at 25, 15 and 5 degrees C. The 30 strains isolated were of only three species of Candida, and none were obligate psychrophils.