A Psychrophilic Cryptococcus

Abstract

A psychrophilic yeast, isolated from decomposing Lantinaria found on the beach a t Hebron Fjord in Labrador, was shown to be a species of Cryptococczis, closely resembling but not identical with C. mucorugoszis and C. terricolus. I n a glucose-salts-vitamins medium, the yeast grew most rapidly a t 25' C, although the final cell crop was greatest in cultures incubated a t 21' C. The yeast grew well a t 3' C after a lag period of approximately five days, but no growth was observed in cultures incubated throughout a t 30° C or above. Cultures of the yeast which had been incubated a t 30° C, but not a t 37O C, grew, on being transferred to 16' C, after a lag period that was proportional to the duration of incubation a t 30° C. The yeast grew well a t 30° C after cultures had been incubated for a period a t 16' C, although growth ceased a t this higher temperature after a few days; further growth a t 30' C could be obtained after the cultures had again been incubated a t 16O C. The significance of these results is discussed in relation t o the psychrophilic behavior of the yeast.'Manuscript

Psychrophilic bacteria.

“…V. psychroerythrus, isolated by Eimjhellen and first reported by Hagen et al (71), has a growth temperature range of 0 to 19 C, with an optimum growth temperature of about 15 C. When this organism was subjected to a temperature shift-up experiment (5 to 19.5 C), there was a slight temporary increase in the growth rate which lasted only 5 h. This increase was followed by a decrease in turbidity (70). The Pseudomonas, studied by Harder and Veldkamp (75) possessed a maximum growth tem- Growth of an Antarctic psychrophile (AP-2-24, designated tentatively as a Vibrio sp.).…”

Denaturation and Renaturation of Malic Dehydrogenase in a Cell-Free Extract From a Marine Psychrophile

“…Hagen and Rose (1961) suggested that the ability of Cryptococcus to survive at 30 C but not at 37 C may be due to heat-sensitive enzymes which are irreversibly denaturated at 37 C but not at 30 C. Ingraham and Bailey (1959) were unable to demonstrate any unusual thermolabile enzymes in the psychrophile they examined. Upadhyay and Stokes (1963) demonstrated a temperature-sensitive formic hydrogenylase from a psychrophilic bacterium which had an optimal activity at 30 C but was completely inactive at 45 C. Rose (1962) cited unpublished data of Hagen on the existence of psychrophilic heatlabile enzymes of the tricarboxylic acid cycle.…”

Psychrophilic and Mesophilic Fungi in Fruit-Filled Pastries

“…The growth and survival of fungi at and below 0 C was reviewed about three decades ago by Berry and Magoon (1934). There have been a few reports concerning psychrophilic yeasts, including those by Scott (1957), Lawrence, Wilson, and Pederson (1959), and Hagen and Rose (1961). The latter workers provided a definition of terms.…”