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: Text
• Language: English
• Published: American Society for Microbiology 2007
• Subjects: Microbial Ecology; Hoare; Lake Hoare; McMurdo Dry Valleys; Antarc*; Antarctica
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1892853; http://www.ncbi.nlm.nih.gov/pubmed/17369347; https://doi.org/10.1128/AEM.00085-07

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 O2. 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.