Description
Summary:Two psychrophilic strains of unicellular algae were isolated from seawater samples collected in the Antarctic Ocean. The one (strain A) was a species of Cymbella (Bacillariophyceae) and the other (strain B) was a species that belonged to the class Prymnesiophyceae (a prymnesiophyte). Optimum temperatures for growth of both the algae were between 2.5℃ and 5℃. Upper limit temperatures for growth of strain A (Cymbella sp.) and strain B were between 12.5℃ and 15℃ and between 7.5℃ and 10℃, respectively. We suggest that these algae should be categorized into extremely psychrophilic algae from their significantly lower cardinal temperatures for growth.