The Water Relations of the Alga Cyanidium caldarium in Soil

Smith, David W.; Brock, Thomas D.

doi:10.1099/00221287-79-2-219

Cited by 28 publications

(11 citation statements)

References 5 publications

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“…Living in soil, the alga Cyanidiurn caldarium has a limiting water potential of about -80 bars (Smith & Brock, 1973). Microcoleus vaginatus, a blue-green alga from a desert crust, was found to have a limiting water potential of -18 to -28 bars (Brock, 1975a), and the coccoid green alga Trebouxia sp.…”

Section: Discussionmentioning

confidence: 99%

“…By using the water-potential concept it is possible to compare the ability of algae from such diverse kinds of environments of low water potential as deserts and salt lakes to tolerate reduced water potential. Smith & Brock (1973) studied the effect of water potential on the thermophilic alga Cyanidium caldarium in geothermal soils, and developed methods applicable to the study of algae in other systems. This work was extended to a study of the blue-green alga Microcoleus vaginatus from a desert crust (Brock,i975a), and the coccoid green alga, Trebouxia sp., present in aerial and terrestrial lichens (Brock, 1975b).…”

Section: T D B R O C Kmentioning

confidence: 99%

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Salinity and the Ecology of Dunaliella from Great Salt Lake

Brock¹

1975

Journal of General Microbiology

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S U M M A R YStudies are reported on the distribution and salinity tolerances of populations of Dunaliella, a eucaryotic alga, in Great Salt Lake, Utah, U.S.A. This lake provides salinities varying from about 10 % (w/v) NaCl to saturated (greater than 30 % w/v). The alga is found throughout this salinity range, although population density varies markedly, mainly because of the influence of grazing animals in waters of low salinity. Enrichment cultures were set up using a range of salinities ; at the lower salinities a wide variety of algae grew, but at the higher ones only Dunaliella was obtained. However, cultures derived from saturated brine and grown at salinities of around 25 % (w/v) were not optimally adapted to these conditions, but grew and photosynthesized better in 10 to 15 % (w/v) NaCl. A natural population from a saturated brine also had an optimum at a lower salinity than its habitat. It is concluded that although this eucaryotic alga is able to grow in saturated brine better than any other alga, it is not optimally adapted to these conditions and is apparently able to maintain populations at high salinity only because it meets no competition from other algae. I N T R O D U C T I O NMembers of the eucaryotic algal genus Dunaliella are widespread in saline environments (Teodoresco, 1905(Teodoresco, , 1906Hof & Fremy, 1933; Lerche, 1937;Volcani, 1944;Smith, 1950; Butcher, I959), and have been much studied, perhaps because of the striking pink to red coloration which they sometimes impart to waters and sediments. The genus Dunaliella was first separated from Chlamydomonas by Teodoresco ( I 905) on morphological grounds, and since then a number of species have been described (Butcher, 1959). These occur in diverse habitats, from almost fresh water to saturated brine, although the salinity requirements of different species have not been specified. Most attention has been paid to cultures able to grow in media of greater salinity than sea water. The mechanism by which Dunaliella withstands high salt concentrations differs from that of the halobacteria (Kushner, I 968 ; Larsen, 1967). In the latter, it appears that the salt concentration (primarily potassium, with some sodium) inside the cell is higher than the external one, permitting water to flow in, and the enzymes of the bacteria are unusually resistant to high concentrations of salt. In Dunaliella, high concentrations of glycerol are synthesized intracellularly through photosynthetic processes (Wegmann, I 971) and the alga maintains an intracellular glycerol concentration such that the intracellular osmotic pressure is higher than the extracellular pressure (Ben-Amotz & Avron, 1g73), thus permitting the alga to take up water even when growing at high salt concentrations. The intracellular salt concentration is lower than the external concentration, and intracellular enzymes of Dunaliellu are actually inhibited by high salt concentrations (Johnson et al. 1968).Despite the evolutionary and ecological interest in this alga, little work has been done in ...

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Section: Discussionmentioning

confidence: 99%

Section: T D B R O C Kmentioning

confidence: 99%

Salinity and the Ecology of Dunaliella from Great Salt Lake

Brock¹

1975

Journal of General Microbiology

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“…2), so the actual temperature the alga was thriving at was arguably lower. Although Galdieria is assumed to have a low desiccation tolerance (Smith & BroCk 1973; and a long-distance transport could be fatal to the cells, its inoculum was apparently able to overcome the distance between the probable source population in Italy and the Ostrava site in a rather short period of time with anemochory or zoochory as the most probable dispersal modes (TopliN et al 2008;CiNiglia et al 2014). For instance, demonstrated that Galdieria from São Miguel Island (Azores) was most closely related to the strain from Southern Spain, which is the closest geographical site to the island .…”

Section: Discussionmentioning

confidence: 99%

Burning coal spoil heaps as a new habitat for the extremophilic red alga Galdieria sulphuraria

Barcytė¹,

Nedbalová²,

Culka³

et al. 2018

Fottea

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Galdieria sulphuraria (Cyanidiales) is a worldwide acclaimed thermoacidophilic red microalga with a limited distribution due to special conditions required for growth and metabolism. Until now, the alga was almost exclusively restricted to acid geothermal environments around the world. However, we have found this species on the surface of a burning coal spoil heap in central Europe. It is the first record of G. sulphuraria in this type of habitat. A rbcL phylogeny confirmed that the population of this extremophile belongs to the continental European lineage and we consider Italian geothermal sites as a potential source of Czech G. sulphuraria. The dispersal of unicellular red microalgae is far from fully understood and the discovery of Galdieria in another region of Europe on a relatively newly established anthropogenic site allows us to understand better the distribution patterns and dispersal abilities of this ecologically important algal group. In addition, we have also analyzed the phylogenetic position of Galdieria strain CCALA 965 isolated from a highly acidic site without geothermal activity in the Czech Republic and confirmed it to belong to the species G. phlegrea, until now known only from Italy.

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“…The algae grow in the springs and colonize surrounding rocks under a silica sinter layer of 2 to 3 mm (Smith and Brock, 1973;Gross et al, 1998). Frequently submerged and exposed to hot, acidic steam from the boiling springs, the rocks provide very unstable conditions for the growth of microorganisms, and the algae are subject to frequent desiccation.…”

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