High abundance of Archaea in Antarctic marine picoplankton

Abstract

Archaea (archaebacteria) constitute one of the three major evolutionary lineages of life on Earth. Previously these prokaryotes were thought to predominate in only a few unusual and disparate niches, characterized by hypersaline, extremely hot, or strictly anoxic conditions. Recently, novel (uncultivated) phylotypes of Archaea have been detected in coastal and subsurface marine waters, but their abundance, distribution, physiology and ecology remain largely undescribed. Here we report exceptionally high archaeal abundance in frigid marine surface waters of Antarctica. Pelagic Archaea constituted up to 34% of the prokaryotic biomass in coastal Antarctic surface waters, and they were also abundant in a variety of other cold, pelagic marine environments. Because they can make up a significant fraction of picoplankton biomass in the vast habitats encompassed by cold and deep marine waters, these pelagic Archaea represent an unexpectedly abundant component of the Earth's biota.

The origin of life?did it occur at high temperatures?

“…In addition, some hyperthermophile sequences are displaced from their basal position if molecular markers other than elongation factors or ATPase subunits are employed (Forterre et al 1993;Klenk et al 1994), i.e., other molecular trees also open up the possibility that the last common ancestor of all living beings was not a thermophilic prokaryote. It could be argued that the discovery of frigid archaea living in Antarctic waters (DeLong et al 1994) supports a low-temperature origin of life, but the same considerations of Fig. 1 apply to these organisms.…”

Application of phylogenetically based hybridization probes to microbial ecology

“…1985; Giovannoni ef al. DeLong 1992;DeLong et al 1994). In fact, the recovery of rRNA sequences carresponding to described species has been the rare exception.…”

Occurrence and distribution of tetraether membrane lipids in soils: Implications for the use of the TEX86 proxy and the BIT index

“…doi: 10.1016/j.orggeochem.2006.07.018 diverse settings such as marine and lacustrine water columns and sediments (e.g. DeLong et al, 1994;MacGregor et al, 1997;Schleper et al, 1997;Vetriani et al, 1999;Jurgens et al, 2000;Karner et al, 2001;Keough et al, 2003), peat bogs, wetlands and soils (e.g. Buckley et al, 1998;Ochsenreiter et al, 2003;Sizova et al, 2003;Kotsyurbenko et al, 2004) and the deep subsurface (Takai et al, 2001).…”