Box 1 | Ace Lake, Vestfold Hills, Antarctica: a model system for studying cold adaptation

From the following article:

Cold-adapted archaea

Ricardo Cavicchioli

Nature Reviews Microbiology 4, 331-343 (May 2006)

doi:10.1038/nrmicro1390

Thirty-seven marine-based systems that are permanently stratified and vary markedly in salinity (4?235 g l-1), temperature (-14 to 24°C), depth (5?110 m), area (3.6?146 ha) and surface level (-30 to 29 m above sea level) exist in the Vestfold Hills region near Davis Base in the Australian Antarctic Territory103. Studies in the area date back to the 1950s (Ref. 104), and have been an integral part of the far-sighted Antarctic Treaty, which was signed in 1959 and denotes Antarctica as a ?natural reserve, devoted to peace and science?, and which remains the mainstay of long-term efforts to preserve the Antarctic wilderness105.

Ace Lake was first visited in 1974 and is the most studied marine-derived meromictic lake in Antarctica106. The saline stratification in the lake maintains zones that are supersaturated with oxygen, through to permanently cold (1?2°C) anoxic bottom waters and sediment that support a methane cycle that has been in existence for the past 3,000 years34, 106. Viruses, protists, copepods, archaea and a broad range of bacteria, including cyanobacteria, aerobic methylotrophs and a large number of novel bacteria, have been isolated from the lake68, 106, 107, 108, 109, 110, and their contributions to biogeochemical cycling has been carefully studied106. Lipid, carotenoid and 16S rRNA analyses have identified the presence of unusual biomarkers and archaea in the lake33, 36, 111, in addition to a Methanosarcina species from 10,000-year-old sediment samples36 and a range of faunal microfossils112. Ace Lake is a pristine system, ideal for studying the biota and biogeochemistry of cold environments. The figure shows an aerial view of Long Fjord near Ace Lake in the Vestfold Hills. The table depicts characteristics of Ace Lake34, 68, 106, 110, 112.

Cold-adapted archaea 

Cold-adapted archaea