No abstract

Thern~ophiles and coliforln bacteria were present in the intestinal tract of certain arctic animals and were sometilnes found in soil and water. Thermophiles survived for a longer period than coliform bacteria when they were inoculated into soil and water simultaneously, and therefore, under natural conditions, some of the thermophiles found in these materials may originate from animal and human feces even though a sample may give a negative test for the presence of colifor~n bacteria.

No abstract

A study of soil microorganisms of Ross Island and the adjacent mainland was carried out during the brief austral summer of 1961-1962. In some cases, seasonal changes in microbial numbers were observed, although microorganisms could not be detected in some soils. Bacterial species common to temperate regions were isolated from a number of different samples. Thermophilic bacteria were present in some of the soils, and a significant portion of the bacterial population was capable of growth at 2 C. The soil microflora were capable of carrying out certain reactions of the nitrogen cycle at a very slow rate. In addition to temperature, other environmental factors which might influence growth and metabolic activity were discussed.

Bacterial counts were generally higher and molds were much more extensive and widely distributed at Paradise Harbor on the Antarctic Peninsula well above the Antarctic Circle, than in areas to the south. Thermophilic bacteria were fou~d only in soils that had been disturbed or contaminated by man and other animals. Mesophilic counts on media made with deioni~ed or sea water, with few exceptions, were in the same range as psychrophiles. Spore-formmg bac~eria were present in regions where contamination had taken place or where birds nested. Dunng the short summer, significant growth response of the soil microflora to organic additives (peptone and glucose) was observed. However, no correlations could be made with physiological and metabolic activity, which showed no measurable increase.