Yeasts in Antarctic soils

The yeast flora of 126 soil samples from the Ross Dependency of Antarctica was examined and compared with that of eight samples from East Greenland. Fifty-two Antarctic samples contained yeasts, in numbers ranging from 5 to over 100,000/g; species isolated belonged to the generaDebaryomyces, Cryptococcus, Candida, Trichosporon andRhodotorula. Nearly all isolates ofCandida were obligate psychrophils; they belonged toCandida scottii, C. nivalis, C. gelida andC. frigida. Duplicate samples, taken at the same site within a few yards of one another, contained the same size and kind of yeast populations. Although not all samples which contained plants (algae, lichens or mosses) contained yeasts, almost all samples which contained yeasts contained plants. There was no correlation between yeast population and the pH of the sample, nor between yeast populations and the presence of vertebrate animals. The samples from East Greenland, which were from an area sufficiently warm and moist to support growth of higher plants, all contained yeasts, in numbers from 200 to 56,000/g. Species isolated were similar to those from Antarctic material.     

Yeasts in some Netherlands soils

Summary In 12 Netherlands soil samples, in two successive analyses carried out in the autumn of 1952, the author has isolated up to 105 cultures of yeasts to be classified under the following species:Kloeckera apiculata, Torulopsis inconspicua, Torulopsis pulcherrima, Candida Guilliermondii, Rhodotorula mucilaginosa, Aureobasidium pullulans, Hansenula saturnus, Hansenula californica, Saccharomyces mangini, Saccharomyces ellipsoideus andPichia membranefaciens. In all the soils examined the quantity of yeasts found has been very small. The results obtained do not offer evidence for any relationship between manurial treatment and species and number of yeasts occurring. Sporeforming yeasts were less numerous than non-sporeforming ones.

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Riassunto Da 12 terreni Olandesi, in due successive analisi, eseguite nell'autunno 1952, l'A. riferisce di avere isolato ben 105 colture pure di lieviti da riportare alle seguenti specie:Kloeckera apiculata, Torulopsis inconspicua, Torulopsis pulcherrima, Candida Guilliermondii, Rhodotorula mucilaginosa, Aureobasidium pullulans, Hansenula saturnus, Hansenula californica, Saccharomyces mangini, Saccharomyces ellipsoideus ePichia membranefaciens. In tutti i terreni esaminati la quantità di lieviti riscontrati è stata molto esigua; non è stata posta in evidenza alcuna influenza in rapporto alle diverse concimazioni ed è stata rilvata la scarsissima diffusione delle specie sporigene su quelle incapaci di formare spore.

     

Chromosome numbers in Compositae from Canada and the U.S.A.

Reports on 267 chromosomes counts are presented from material of known wild origin referable to 128 taxa of Compositae native to North America, or aliens growing there in a wild state.