Cold-Active Chemoorganotrophic Bacteria from Permanently Ice-Covered Lake Hoare, McMurdo Dry Valleys, Antarctica

• Published in: Applied and Environmental Microbiology
• Main Authors: Clocksin, Kate M., Jung, Deborah O., Madigan, Michael T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Society for Microbiology 2007
• Subjects: Hoare; Lake Hoare; McMurdo Dry Valleys; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1128/aem.00085-07; https://journals.asm.org/doi/pdf/10.1128/AEM.00085-07

ABSTRACT Eight strains of chemoorganotrophic bacteria were isolated from the water column of Lake Hoare, McMurdo Dry Valleys, Antarctica, using cold enrichment temperatures. The isolates were Alpha -, Beta -, and Gammaproteobacteria and Actinobacteria spp. All isolates grew at 0°C, and all but one grew at subzero temperatures characteristic of the water column of Lake Hoare. Growth temperature optima varied among isolates, but the majority showed optima near 15°C, indicative of cold-active phenotypes. One isolate was truly psychrophilic, growing optimally around 10°C and not above 20°C. Half of the isolates grew at 2% salt while the other half did not, and all but one isolate grew at 2 atm of O 2 . Our isolates are the first prokaryotes from the water column of Lake Hoare to be characterized phylogenetically and physiologically and show that cold-active species of at least two major phyla of Bacteria inhabit Lake Hoare.