Osmoadaptation in Archaea

Martin, Deana D.; Ciulla, Rose A; Roberts, Mary F.

doi:10.1128/aem.65.5.1815-1825.1999

Cited by 169 publications

(92 citation statements)

References 78 publications

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“…H. salifodinae BK18 grows with a lag time of 11.9 h with a doubling time of 22 h and a maximum specific growth rate of 0.99 days 21 . The copious amounts of brick-red precipitate formed in the presence of Na 2 SeO 3 interfered with the absorbance measurements at 600 nm giving a false positive result.…”

Section: Resultsmentioning

confidence: 99%

“…They maintain their osmolarity by intracellular accumulation of KCl (up to 5M) that counteracts the ionic strength of the extracellular environment. 21 Haloarchaea are known to encounter metals in their environment, but their metal tolerance has not been well documented. Many metal resistance genes have been annotated in model organism Halobacterium sp.…”

Section: Introductionmentioning

confidence: 99%

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In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti‐proliferative properties against HeLa cell line

Srivastava

Bragança

Kowshik

2014

Biotechnology Progress

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Nanoparticles synthesis by bacteria and yeasts has been widely reported, however, synthesis using halophilic archaea is still in a nascent stage. This study aimed at the intracellular synthesis of selenium nanoparticles (SeNPs) by the haloarchaeon Halococcus salifodinae BK18 when grown in the presence of sodium selenite. Crystallographic characterization of SeNPs by X-ray diffraction, Selected area electron diffraction, and transmission electron microscopy exhibited rod shaped nanoparticles with hexagonal crystal lattice, a crystallite domain size of 28 nm and an aspect ratio (length:diameter) of 13:1. Energy disruptive analysis of X-ray analysis confirmed the presence of selenium in the nano-preparation. The nitrate reductase enzyme assay and the inhibitor studies indicated the involvement of NADH-dependent nitrate reductase in SeNPs synthesis and metal tolerance. The SeNPs exhibited good anti-proliferative properties against HeLa cell lines while being non-cytotoxic to normal cell line model HaCat, suggesting the use of these SeNPs as cancer chemotherapeutic agent. This is the first study on selenium nanoparticles synthesis by haloarchaea.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti‐proliferative properties against HeLa cell line

Srivastava

Bragança

Kowshik

2014

Biotechnology Progress

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“…This mechanism, which was discovered in and is typical of members of the Halobacteriaceae [9,10], achieves osmotic equilibrium by maintaining a cytoplasmic salt concentration (KCl) similar to that of the bathing solution. As a consequence, the cytoplasm is exposed to high ionic strength (up to 7 M KCl has been recorded in species of Halobacterium [11]) and as such requires extensive structural adaptations.…”

Section: Salt In Cytoplasm; the Halobacterial Solutionmentioning

confidence: 99%

Bacterial osmoadaptation: the role of osmolytes in bacterial stress and virulence

Sleator¹

2001

FEMS Microbiology Reviews

219

288

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Two general strategies exist for the growth and survival of prokaryotes in environments of elevated osmolarity. The 'salt in cytoplasm' approach, which requires extensive structural modifications, is restricted mainly to members of the Halobacteriaceae. All other species have convergently evolved to cope with environments of elevated osmolarity by the accumulation of a restricted range of low molecular mass molecules, termed compatible solutes owing to their compatibility with cellular processes at high internal concentrations. Herein we review the molecular mechanisms governing the accumulation of these compounds, both in Gram-positive and Gram-negative bacteria, focusing specifically on the regulation of their transport/synthesis systems and the ability of these systems to sense and respond to changes in the osmolarity of the extracellular environment. Finally, we examine the current knowledge on the role of these osmostress responsive systems in contributing to the virulence potential of a number of pathogenic bacteria. ß

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“…Comparing the solutes accumulated in Archaea and Bacteria, striking differences become evident. Most archaeal compatible solutes resemble their bacterial counterpart in structure, with the difference that the majority of them carry a negative charge (Martin et al, 1999). This anionic character is conferred to the solutes by the addition of a carboxylate, phosphate or sulphate group.…”

Section: Compatible Solutesmentioning

confidence: 99%

“…The`salt-in-cytoplasm-type' has been found in Halobacteria but will not be discussed here. Accumulation of compatible solutes is found, amongst others, in methanogenic archaea in which it has been studied to some detail (Martin et al, 1999;Roberts, 2000). However, most studies dealt with the identification and characterization of compatible solutes but little is known about the physiology of the osmoresponse.…”

Section: Response To Osmotic Upshockmentioning

confidence: 99%

Osmoadaptation in bacteria and archaea: common principles and differences

Roeßler¹,

Müller²

2001

Environmental Microbiology

262

222

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The availability of water is the most important prerequisite for life of any living cell, and exposure of cells to hypersaline conditions always threatens the cells with a drastic loss of water. To re-establish the essential turgor pressure, cells increase the water activity of their cytoplasm by accumulation of compatible solutes, either by synthesis or by uptake. The ability to respond to increasing osmolality is well conserved in all three lines of descent and, here, we compare the osmoadaptive strategies of Bacteria and Archaea. The temporal sequence of events after an osmotic upshock will be discussed, with a focus on the most rapid response, notably the mechanisms of transport activation at the protein level, and different signals for osmolality will be compared. The spectrum of compatible solutes used by different organisms is rather diverse and a comparison of 'bacterial' and 'archaeal' compatible solutes will be given.

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Osmoadaptation in Archaea

Cited by 169 publications

References 78 publications

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti‐proliferative properties against HeLa cell line

In vivo synthesis of selenium nanoparticles by Halococcus salifodinae BK18 and their anti‐proliferative properties against HeLa cell line

Bacterial osmoadaptation: the role of osmolytes in bacterial stress and virulence

Osmoadaptation in bacteria and archaea: common principles and differences

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