A Ciliate from the Dead Sea

Elazari-Volcani, B.

doi:10.1038/154335a0

Cited by 27 publications

(11 citation statements)

References 1 publication

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“…Kirby () described a small, new species of ciliate, Rhopalophrya salina collected in concentrated brine from Searles Lake, California. A small, unidentified ciliate species, possibly belonging to the genus Cyclidium , was isolated from the Dead Sea (Elazari‐Volcani ).…”

Section: Discovery Of Ciliates In Extreme Environmentsmentioning

confidence: 99%

Ciliates in Extreme Environments

2014

J Eukaryotic Microbiology

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As eukaryotic microbial life, ciliated protozoan may be found actively growing in some extreme condition where there is a sufficient energy source to sustain it because they are exceedingly adaptable and not notably less adaptable than the prokaryotes. However, a crucial problem in the study of ciliates in extreme environments is the lack of reliable cultivation techniques. To our knowledge, only a tiny fraction of ciliates can be cultured in the laboratory, even for a very limited period, which can partly explain the paucity of our understanding about ciliates diversity in various extremes although the interest in the biodiversity of extremophiles increased significantly during the past three decades. This mini-review aims to compile the knowledge of several groups of free-living ciliates that can be microscopically observed in extreme environmental samples, although most habitats have not been sufficiently well explored for sound generalizations.

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Section: Discovery Of Ciliates In Extreme Environmentsmentioning

confidence: 99%

Ciliates in Extreme Environments

2014

J Eukaryotic Microbiology

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“…However, the causes of the decline in the numbers of viable coliforms in seawater and in Dead Sea water may be very different: the activity of protozoa is thought to be one of the main causes of the disappearance of coliform bacteria from seawater [16,21,22]. Though some protozoa have been cultured from the Dead Sea in the past [2,3] no protozoa have been found in the many Dead Sea water samples examined in recent years [12,23]. The bactericidal effect of Dead Sea water was found to be due to its salt concentrations.…”

Section: Bacterialmentioning

confidence: 99%

“…The Dead Sea has long been considered a sterile environment, hostile to all forms of life, and it was not until the 1930s that the lake was found to support a variety of indigenous microorganisms adapted to the extremely high salt concentrations and the specific composition of the salts present. Halophilic bacteria, green flagellate algae, and even halophilic protozoa [1][2][3] were ,isolated from the lake water and sediments.…”

Section: Introductionmentioning

confidence: 99%

Survival ofEscherichia coliandVibrio harveyiin Dead Sea water

Oren

Vlodavsky

1985

FEMS Microbiology Letters

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When suspensions of Escherichia coli or the marine luminescent bacterium Vibrio harveyi were mixed with Dead Sea water, the number of viable bacteria decreased by 90% in a time varying from less than 1 h to several hours, depending on the bacterial strain tested. Survival was better at low temperatures, and diluting the Dead Sea water permitted prolonged survival of both coliform bacteria and V. harveyi. The death rate of E. coli in Dead Sea water was comparable to that in water from the Great Salt Lake (Utah). The high concentrations of calcium and magnesium in Dead Sea water, rather than the high total salinity, was identified as the main factor responsible for the rapid die‐off. Exposure to direct solar irradiation significantly increased the die‐off rate of E. coli in Dead Sea water. Large numbers of coliform bacteria were recovered from the lake at distances of at least 20 m from a sewage discharge site on the western shore of the Dead Sea.

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“…Such bloom events were monitored in 1980 and 1992 and were followed by blooms of Archaea living on the exudates of the autotrophic algae (Oren & Shilo, , ; Oren, ; Oren et al ., ). In addition to these microorganisms, several Archaea and Bacteria species, as well as protozoa and ciliates have been isolated from the water column and the sediments of the lake (Elazari‐Volcani, , b, ; Oren, ). Sulfate‐reducing bacteria (SRB) have never been isolated from the Dead Sea (Oren, ).…”

Section: Introductionmentioning

confidence: 99%

Sulfate reduction and sulfide oxidation in extremely steep salinity gradients formed by freshwater springs emerging into the Dead Sea

Häusler

Weber

Siebert

et al. 2014

FEMS Microbiol Ecol

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Abundant microbial mats, recently discovered in underwater freshwater springs in the hypersaline Dead Sea, are mostly dominated by sulfur-oxidizing bacteria. We investigated the source of sulfide and the activity of these communities. Isotopic analysis of sulfide and sulfate in the spring water showed a fractionation of 39-50‰ indicative of active sulfate reduction. Sulfate reduction rates (SRR) in the spring sediment (< 2.8 nmol cm(-3) day(-1)) are too low to account for the measured sulfide flux. Thus, sulfide from the springs, locally reduced salinity and O2 from the Dead Sea water are responsible for the abundant microbial biomass around the springs. The springs flow is highly variable and accordingly the local salinities. We speculate that the development of microbial mats dominated by either Sulfurimonas/Sulfurovum-like or Thiobacillus/Acidithiobacillus-like sulfide-oxidizing bacteria, results from different mean salinities in the microenvironment of the mats. SRR of up to 10 nmol cm(-3) day(-1) detected in the Dead Sea sediment are surprisingly higher than in the less saline springs. While this shows the presence of an extremely halophilic sulfate-reducing bacteria community in the Dead Sea sediments, it also suggests that extensive salinity fluctuations limit these communities in the springs due to increased energetic demands for osmoregulation.

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A Ciliate from the Dead Sea

Cited by 27 publications

References 1 publication

Ciliates in Extreme Environments

Ciliates in Extreme Environments

Survival ofEscherichia coliandVibrio harveyiin Dead Sea water

Sulfate reduction and sulfide oxidation in extremely steep salinity gradients formed by freshwater springs emerging into the Dead Sea

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