TY - JOUR
T1 - The unique 16S rRNA genes of piezophiles reflect both phylogeny and adaptation
AU - Lauro, Federico M.
AU - Chastain, Roger A.
AU - Blankenship, Lesley E.
AU - Yayanos, A. Aristides
AU - Bartlett, Douglas H.
PY - 2007/2
Y1 - 2007/2
N2 - In the ocean's most extreme depths, pressures of 70 to 110 megapascals prevent the growth of all but the most liyperpiezophilic (pressure-loving) organisms. The physiological adaptations required for growth under these conditions are considered to be substantial. Efforts to determine specific adaptations permitting growth at extreme pressures have thus far focused on relatively few γ-proteobacteria, in part due to the technical difficulties of obtaining piezophilic bacteria in pure culture. Here, we present the molecular phylogenies of several new piezophiles of widely differing geographic origins. Included are results from an analysis of the first deep-trench bacterial isolates recovered from the southern hemisphere (9.9-km depth) and of the first gram-positive piezophilic strains. These new data allowed both phylogenetic and structural 16S rRNA comparisons among deep-ocean trench piezophiles and closely related strains not adapted to high pressure. Our results suggest that (i) the Circumpolar Deep Water acts as repository for liyperpiezophiles and drives their dissemination to deep trenches in the Pacific Ocean and (ii) the occurrence of elongated helices in the 16S rRNA genes increases with the extent of adaptation to growth at elevated pressure. These helix changes are believed to improve ribosome function under deep-sea conditions.
AB - In the ocean's most extreme depths, pressures of 70 to 110 megapascals prevent the growth of all but the most liyperpiezophilic (pressure-loving) organisms. The physiological adaptations required for growth under these conditions are considered to be substantial. Efforts to determine specific adaptations permitting growth at extreme pressures have thus far focused on relatively few γ-proteobacteria, in part due to the technical difficulties of obtaining piezophilic bacteria in pure culture. Here, we present the molecular phylogenies of several new piezophiles of widely differing geographic origins. Included are results from an analysis of the first deep-trench bacterial isolates recovered from the southern hemisphere (9.9-km depth) and of the first gram-positive piezophilic strains. These new data allowed both phylogenetic and structural 16S rRNA comparisons among deep-ocean trench piezophiles and closely related strains not adapted to high pressure. Our results suggest that (i) the Circumpolar Deep Water acts as repository for liyperpiezophiles and drives their dissemination to deep trenches in the Pacific Ocean and (ii) the occurrence of elongated helices in the 16S rRNA genes increases with the extent of adaptation to growth at elevated pressure. These helix changes are believed to improve ribosome function under deep-sea conditions.
UR - http://www.scopus.com/inward/record.url?scp=33846919848&partnerID=8YFLogxK
U2 - 10.1128/AEM.01726-06
DO - 10.1128/AEM.01726-06
M3 - Article
C2 - 17158629
AN - SCOPUS:33846919848
SN - 0099-2240
VL - 73
SP - 838
EP - 845
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
IS - 3
ER -