The Chemical Composition of Isolated Cell Walls of Cyanidium caldarium

Bailey, R. W.; Staehelin, L. Andrew

doi:10.1099/00221287-54-2-269

Cited by 45 publications

(17 citation statements)

References 11 publications

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“…The mechanism by which this temporary impermeability to protons is achieved is unknown. However, G. sulphuraria possesses a very rigid protein-rich cell wall (Bailey and Staehelin, 1968;Staehelin, 1968), and it has been hypothesized, based on studies with archaebacteria, that the incorporation of sterols, saturated fatty acids, bipolar tetraether lipids, and proteins could account for this impermeability (Benz and Cros, 1978;Benz et al, 1980;Elferink et al, 1992;Komatsu and Chong, 1998). Very long chain dicarboxylic acids are thought to have similar roles in some eubacteria (Jung et al, 1993(Jung et al, , 1994Burdette et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

EST-analysis of the thermo-acidophilic red microalga Galdieriasulphuraria reveals potential for lipid A biosynthesis and unveils the pathway of carbon export from rhodoplasts

et al. 2004

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When we think of extremophiles, organisms adapted to extreme environments, prokaryotes come to mind first. However, the unicellular red micro-alga Galdieria sulphuraria (Cyanidiales) is a eukaryote that can represent up to 90% of the biomass in extreme habitats such as hot sulfur springs with pH values of 0-4 and temperatures of up to 56°C. This red alga thrives autotrophically as well as heterotrophically on more than 50 different carbon sources, including a number of rare sugars and sugar alcohols. This biochemical versatility suggests a large repertoire of metabolic enzymes, rivaled by few organisms and a potentially rich source of thermo-stable enzymes for biotechnology. The temperatures under which this organism carries out photosynthesis are at the high end of the range for this process, making G. sulphuraria a valuable model for physical studies on the photosynthetic apparatus. In addition, the gene sequences of this living fossil reveal much about the evolution of modern eukaryotes. Finally, the alga tolerates high concentrations of toxic metal ions such as cadmium, mercury, aluminum, and nickel, suggesting potential application in bioremediation. To begin to explore the unique biology of G. sulphuraria, 5270 expressed sequence tags from two different cDNA libraries have been sequenced and annotated. Particular emphasis has been placed on the reconstruction of metabolic pathways present in this organism. For example, we provide evidence for (i) a complete pathway for lipid A biosynthesis; (ii) export of triose-phosphates from rhodoplasts; (iii) and absence of eukaryotic hexokinases. Sequence data and additional information are available at http://genomics.msu.edu/galdieria.

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Section: Introductionmentioning

confidence: 99%

EST-analysis of the thermo-acidophilic red microalga Galdieriasulphuraria reveals potential for lipid A biosynthesis and unveils the pathway of carbon export from rhodoplasts

et al. 2004

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“…We cannot compare the silicification of C. caldarium with that of other microbes, however, because other types are rarely found in this environment (e.g., pH < 2, sulfuric acid, high temperature, etc.). One must note that C. caldarium has a specific type of cell wall (Nagashima & Fukuda 1981, Bailey & Staehelin 1968) and a great ability to regulate pH to permit its tolerance to acid (Enami et al 1986). Examples of specificity of the cell walls are that the protein is rich in the amino acids serine and threonine, and that the polysaccharide is rich in hemicellulose (Bailey & Staehelin 1968).…”

Section: Silica Biomineralization Of Unicellular Microbes Under Acidimentioning

confidence: 99%

“…One must note that C. caldarium has a specific type of cell wall (Nagashima & Fukuda 1981, Bailey & Staehelin 1968) and a great ability to regulate pH to permit its tolerance to acid (Enami et al 1986). Examples of specificity of the cell walls are that the protein is rich in the amino acids serine and threonine, and that the polysaccharide is rich in hemicellulose (Bailey & Staehelin 1968). The great ability to regulate pH also causes a strong gradient in pH across the external walls of the cell with fluctuation in pH.…”

Section: Silica Biomineralization Of Unicellular Microbes Under Acidimentioning

confidence: 99%

Silica Biomineralization of Unicellular Microbes Under Strongly Acidic Conditions

Asada¹,

Tazaki²

2001

The Canadian Mineralogist

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Silica biomineralization associated with unicellular microbes (Cyanidium caldarium) living in strongly acidic hot springs were observed by electron microscopy. The unicellular microbes form green biomats undergoing photosynthesis in Kamuiwakka Falls, Hokkaido, Japan. The hot-spring water is strongly acidic, with pH less than 2, and rich in S. Electron microscopy observations showed that the cell walls of unicellular microbes served as sites for nucleation of silica, polymerization of silicic acid and adhesion of colloidal silica. The precipitates formed an amorphous silica crust on the cell walls, which consist of granular silica spherules with a uniform size. The spherules commonly assimilate the cell walls. Data from X-ray diffraction and electron diffraction of the silica crusts reveal that the crusts are amorphous or of low crystallinity. Electron-dispersion X-ray spectroscopy also showed that the crusts are mainly composed of Si with traces of S and Cl. The unicellular microbes have a double-layer cell wall; therefore, silica crusts may form a double layer. FT-IR spectra of cells with and without silica crusts indicated that N-H, C=O and C-N-H bands were derived from peptides in cells, whereas the Si-O band was derived from silica crusts. Some models also are suggested on the interaction between cell wall and silica under strongly acidic conditions. Processes of silica biomineralization of unicellular microbes as described in this paper have profound implications for evolution of siliciferous microbes.

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“…This acid-tolerant and heattolerant unicellular alga is a regular member of the microflora found in acidic hot springs throughout the world (2,4). Electron microscopic investigations show a highly differentiated cell containing: a thick cell wall, plasmalemma, ground matrix, endoplasmic reticulum, chloroplast, mitochondria, nucleus, and vacuoles (14).…”

mentioning

confidence: 99%

Effect of Growth Temperature on the Lipid Composition of Cyanidium caldarium

Kleinschmidt

McMahon

1970

Plant Physiol.

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Cyanidium caldarium is a thermophilic eucaryote which can grow at temperatures below 20 C and has been reported growing at temperatures up to 56 C (5). This acid-tolerant and heattolerant unicellular alga is a regular member of the microflora found in acidic hot springs throughout the world (2,4). Electron microscopic investigations show a highly differentiated cell containing: a thick cell wall, plasmalemma, ground matrix, endoplasmic reticulum, chloroplast, mitochondria, nucleus, and vacuoles (14). Cell division occurs by formation of four daughter cells within the mother cell wall, and after rupturing the four daughter cells are released. These morphological characteristics make it quite suitable for studying the effect of temperature on lipid composition and its possible role in the molecular mechanism of thermophily.In order to develop and function properly, organisms must be capable of adjusting to their environment. Of the environmental factors, temperature is an important parameter determining the lethal ranges of survival. Since temperature affects all biological reactions, the over-all effect of temperature is rather complex; therefore, this investigation is limited to a narrower set of biological reactions: lipid metabolism.It has been well documented that an increase in temperature causes a corresponding decrease in the amount of unsaturated fatty acids (3,6, 8,10,13). Farkas and Herodek (6)

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The Chemical Composition of Isolated Cell Walls of Cyanidium caldarium

Cited by 45 publications

References 11 publications

EST-analysis of the thermo-acidophilic red microalga Galdieriasulphuraria reveals potential for lipid A biosynthesis and unveils the pathway of carbon export from rhodoplasts

EST-analysis of the thermo-acidophilic red microalga Galdieriasulphuraria reveals potential for lipid A biosynthesis and unveils the pathway of carbon export from rhodoplasts

Silica Biomineralization of Unicellular Microbes Under Strongly Acidic Conditions

Effect of Growth Temperature on the Lipid Composition of Cyanidium caldarium

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