The soluble carbohydrates of Euglena gracilis—their identity and response to increased external solute concentration

Abstract Mannitol and trehalose were the predominant soluble carbohydrates in Euglena gracilis strain z growing heterotrophically in complete darkness or in light. The ratio of trehalose to mannitol was correlated with the water activity of the medium. That is, extracts of Euglena gracilis adapted to grow in media supplemented with either sodium chloride or glucose, thereby reducing the water activity, yielded molar ratios of trehalose to mannitol 10 times greater than extracts of cultures grown under conditions in common usage.     

The Molecular Biology of Euglena gracilis IX. Amino Acid Pool Composition

The amino acid composition of the acid soluble fraction of Euglena gracilis was determined from cells grown in 4 different culture media. Glutamic acid is the major free amino acid. Hydrolysis of this fraction increases the amount of free amino groups, the major amino acids found are then glutamic acid, aspartic acid, glycine and arginine. The pattern of amino acid distribution is similar in all 4 culture media. L-arginyl-L-glutamine was isolated and identified in extracts from all 4 culture conditions. It was shown to be a metabolic intermediate by radioactivity chase experiments.     

PHYLOGENY AND SYSTEMATICS OF EUGLENA (EUGLENACEAE) SPECIES WITH AXIAL,STELLATE CHLOROPLASTS BASED ON MORPHOLOGICAL AND MOLECULAR DATA—NEW TAXA,EMENDED DIAGNOSES,AND EPITYPIFICATIONS1

Morphological and molecular studies, as well as original literature reexamination, necessitate establishment of five Euglena species with a single axial, stellate chloroplast [Euglena viridis (O. F. Müller) Ehrenberg 1830 , Euglena pseudoviridis  Chadefaud 1937 , Euglena stellata  Mainx 1926 , Euglena pseudostellata sp. nov., and Euglena cantabrica  Pringsheim 1956 ], three species with two chloroplasts (Euglena geniculata Dujardin ex Schmitz 1884 , Euglena chadefaudii  Bourrelly 1951 , and Euglena pseudochadefaudii sp. nov.), and one species with three chloroplasts (Euglena tristella  Chu 1946 ). The primary morphological features, allowing distinction of the considered species are the presence and the shape of mucocysts, as well as the number of chloroplasts. Spherical mucocysts occur in E. cantabrica and E. geniculata, while spindle‐shaped mucocysts are present in E. stellata, E. pseudostellata, E. chadefaudii, E. pseudochadefaudii, and E. tristella. No mucocysts are observed in E. viridis and E. pseudoviridis. Two new species (E. pseudochadefaudii sp. nov. and E. pseudostellata sp. nov.) differ from the respective species, E. chadefaudii and E. stellata, only at the molecular level. Molecular signatures and characteristic sequences are designated for nine distinguished species. Emended diagnoses for all and delimitation of epitypes for seven species (except E. viridis and E. tristella) are proposed.     

Zur Kenntnis einiger Arten vonEuglena

Zusammenfassung Beim Studium einer größeren Zahl ökologisch verschiedener Arten vonEuglena in Reinkultur ergab sich folgendes: morphologisch, brauchten die früheren Angaben nur ergänzt zu werden, wobei die reversible Modifizierbarkeit noch besser gegen die erbliche Variabilität abgegrenzt wurde.Die einzige, bisher eingehend physiologisch untersuchte ArtEuglena gracilis ist ein durch weite Anpassungsfähigkeit in der Ernährung ausgezeichneter extremer Fall. Doch machen auch Stämme vonEuglena deses undEuglena viridis guten Gebrauch von organischen Nährstoffen, währendEuglena acus undEuglena sanguinea ganz phototroph sind.Euglena pisciformis ist gleichfalls phototroph, gedeiht aber auch in verschmutztem Wasser, was beiEuglena sanguinea nur in geringem Maße der Fall ist.FürEuglena deses var.Mesnili wurden in der Literatur verbreitete Mißverständnisse und Fehlschlüsse berichtigt.Allen Arten gemeinsam ist der Bedarf an Vitamin B₁₂ und die Bevorzugung von Ammonstickstoff, während die Verwertung von Nitrat nur selten vorkommt.Wachstum im Dunkeln ist nur bei wenigen Arten erzielt worden. Sie ist mit dem Unterbleiben der Chlorophyllbildung verbunden.Die Ergebnisse entsprechen im großen und ganzen den Bedingungen an den Standorten der Arten.

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Summary By studying a number of ecologically differing species ofEuglena in axenic cultures the following results were obtained:With respect to morphology my earlier statements only needed supplementing. Reversible modificability gained a clearer separation from hereditary variability.The only species hitherto thoroughly investigated as to its physiology wasEuglena gracilis. It proved to be an extreme case of nutritional adaptability being able to live photoautotrophically as well as to utilize various organic nutrients and even to grow almost as luxuriantly in the dark as in the light.Strains ofEuglena deses andEuglena viridis may also make good use of organic nutrients, though not producing without photosynthesis populations as dense as those ofEuglena gracilis. Euglena acus andEuglena sanguinea are quite predominantly phototrophic, and so isEuglena pisciformis which, however, penetrates into polluted water, a faculty not so well developed inEuglena sanguinea. Euglena deses var.Mesnili had been the object of widespread misunderstanding and wrong conclusions which were corrected in detail.All species have in common a requirement of vitamin B₁₂ and the preference of Ammon-N, while utilization of Nitrate is a rare instance.Growth in the dark has been achieved only in a few species. It is always combined with the lack of chlorophyll formation.On the whole the results are conform to the conditions at the respective habitats.

     

A new photosynthetic euglenoid isolated in Poland: Euglenaria clepsydroides sp. nov. (Euglenea)

In this paper, we describe a new photosynthetic euglenoid species, Euglenaria clepsydroides Zakry?, sp. nov., found in Poland. A large population of this species exists in a few, small, eutrophic bodies of water inside the Masurian Landscape Park (covering a part of the Masurian Lake District in Poland). The characteristic and atypical (hourglass-like) cell shape sets it well apart from the other species that have been described up to now. This atypical cell shape has so far been observed only in three species – Lepocinclis constricta, Euglena undulata and Euglena gymnodinioides – whose other morphological characteristics, such as the number and morphology of chloroplasts, the lack of mucocysts, and nuclear SSU rDNA sequence data, exclude the possibility that they could be close relatives of Euglenaria clepsydroides. On the phylogenetic tree, the new species is situated within the Euglenaria clade. While it is a sister group of the clade that includes representatives of Euglenaria anabaena, the two species are clearly morphologically distinct.     

PHYLOGENETIC AND TAXONOMIC POSITION OF LEPOCINCLIS FUSCA COMB. NOV. (=EUGLENA FUSCA) (EUGLENACEAE): MORPHOLOGICAL AND MOLECULAR JUSTIFICATION1

We studied the morphological diversity and analyzed the small subunit rDNA sequences of two taxa formerly known as Euglena spirogyra Ehr. and Euglena fusca (Klebs) Lemmermann. Our studies confirmed that the two should have the rank of a species, namely Lepocinclis spirogyroides (Ehr.) Marin et Melkonian and Lepocinclis fusca (Klebs) Kosmala et Zakry? comb. nov. (Euglenophyceae). We are defining new diagnostic features for these species, namely the size and the shape of the cells and the shape of the papillae, as well as designating epitypes for them.     

Osservazioni ultrastrutturali su particolari organelli polimembranosi in Euglena gracilis

Abstract

Ultrastructural observations on polymembranous organelles in Euglena gracilis. Polymembranous organelles, similar to hypertrophied mitochondria, seen in the cytoplasm of bleached or photosynthetic Euglena gracilis cells are presented.     

TWO DIFFERENT SPECIES OF EUGLENA,E. GENICULATA AND E. MYXOCYLINDRACEA (EUGLENOPHYCEAE), ARE VIRTUALLY GENETICALLY AND MORPHOLOGICALLY IDENTICAL1

We investigated the similarity of a single Euglena myxocylindracea strain, isolated originally by Bold and MacEntee, to several Euglena geniculata strains on both morphological and DNA levels. We found the three DNA stretches, consisting of fragments coding for the parts of cytoplasmic and chloroplast small subunit rRNA, and the internal transcribed spacer (ITS2) of cytoplasmic rDNA, with the combined length of 4332 nucleotides, are identical in E. myxocylindracea and E. geniculata, strain SAG 1224‐4b. Morphological differences between E. myxocylindracea and any E. geniculata strain examined were well within the range of E. geniculata variability as well. The only difference behind the distinction of E. myxocylindracea from E. geniculata is the presence of the second chloroplast in the latter. However, we were able to induce the appearance of the second chloroplast in the cells of E. myxocylindracea and its disappearance in the cells of E. geniculata by changing the composition of the culture media. We therefore conclude that E. myxocylindracea Bold and MacEntee should be regarded as an environmental form of E. geniculata Dujardin. For the first time the morphology of E. geniculata chloroplasts was shown as revealed by confocal laser microscopy.     

Ferric and manganic superoxide dismutases in Euglena gracilis.

Iron-containing superoxide dismutase was found in the soluble fraction from Euglena gracilis and Mn-superoxide dismutase was found in the thylakoid-bound form. Two major Fe-superoxide dismutases were isolated from the soluble fraction in the homogeneous state. Their absorption spectra, molecular weights, subunit structures, and metal contents resemble those of the Fe-enzymes from procaryotes. However,the Euglena enzymes are more sensitive to heating, to denaturants, and to H₂O₂ and less sensitive to azide than are the procaryote enzymes. The amino acid composition of the Euglena enzyme differs substantially from the compositions of the enzymes from procaryotes.     

Glycolate excretion by air-grown Euglena graeilis z

In contrast to reported fact, the air-grown cells of Euglena gracilis z were found to excrete glycolate into the surrounding medium, when placed in an atmosphere of 100% O₂ under illumination at 20000 lux at the same rate of the 5% CO₂-grown cells, but with a lag phase of about 30 min. The lag was eliminated by lowering intracellular CO₂ concentration in the air-grown cells.This paper is the eighth in a series on the metabolism of glycolate in Euglena gracilis.     

Changes of the plastid system of Euglena gracilis induced with streptomycin and dihydrostreptomycin

Summary Streptomycin-like antibiotics cause hereditary and irreversible aplastidity of Euglena gracilis by inhibiting the replication of plastids, while normal cell division is maintained.Therefore, a gradual dilution of plastids takes place in a multiplying culture. Streptomycin was found to be more effective as bleaching agent than dihydrostreptomycin. The cells of Euglena gracilis are totally deprived of plastids by streptomycin treatment after 4.5 cell divisions, while 9 cell divisions are required with dihydrostreptomycin. In addition to the inhibition of plastid replication both antibiotics bring about formation of pathological plastids, both in growing and in stationary cultures. In this latter case pathological plastids are released from cells only after further cell division has taken place.     

Salzwasser-Eugleninen

Zusammenfassung Es wird dargelegt, daß das Vorkommen von Eugleninen in Brackwasser keine seltene Erscheinung ist. Die Arten der Gattung Eutreptia sind alle an mehr oder weniger salzhaltiges Wasser gebunden. Von Euglena leben Varietäten bekannter Arten in Brackwasser, die meisten aber in Süßwasser.Eine Art von Eutreptia (E. pertyi) und fünf Varietäten von Euglena viridis, Euglena proxima und Euglena deses werden als neu beschrieben.Die beiden untersuchten Arten von Eutreptia haben einen Paramylonherd, von dem, wie bei Euglena viridis, Chloroplastenbänder ausstrahlen, welche aber leicht in kleinere Elemente zerfallen. Otto Renner zum 70. Geburtstag gewidmet.     

Winter phytoplankton communities of Utah Lake,Utah, USA

Phytoplankton samples were collected from ice-covered Utah Lake during February and March, 1979 in order to characterize the winter algal flora. These samples were analyzed for presence and abundance of diatoms and non-diatom algae as well as selected water chemical parameters. A total of 159 diatom taxa and 20 non-diatoms was found in the water column under the ice. The flagellates Carteria stellifera, Euglena gracilis and Chlamydomonas globosa dominated the winter non-diatom flora while Stephanodiscus cf. dubius, Cyclotella meneghiniana, Navicula minima, Fragilaria construens var. venter, and Melosira granulata var. angustissima dominated the winter diatom flora. Species richness and abundance were elevated in the major bays of the lake.     

Compatible solutes of sclerotia of Mycoleptodiscus terrestris under different culture and drying conditions

Mycoleptodiscus terrestris is a plant pathogen which has been shown to be effective in controlling invasive aquatic weeds in inundative biocontrol applications. The preferred propagule for production and application is the sclerotium. In the current study, we evaluated the accumulation of carbohydrates and polyols in the sclerotia of M. terrestris under different culture and drying regimes. The carbohydrates and polyols screened for represent a class of compatible solutes found in fungi. The results show mannitol and trehalose are the major analytes identified in the sclerotia of M. terrestris. We identified higher levels of mannitol and trehalose in liquid-culture produced samples relative to solid-state produced samples. The impact of fermentation time was examined and shown to impact solute levels. In addition, the drying regime was varied to produce samples dried to different moisture contents. The experiments show greater drying led to higher mannitol levels, while trehalose levels remained constant. Rapid drying of the sclerotia in a fluidized-bed dryer also show rapid accumulation of mannitol and trehalose, which suggest the enzyme activities needed for production are readily available. The findings confirm mannitol and trehalose are important metabolites in M. terrestris and their concentrations are responsive to osmotic stress conditions.     

Amminoacidi Liberi in Euglena

Abstract

Free amino acids in EUGLENA. — The free amino acids present in Euglena gracilis strain Z, cultivated in the light and the dark, as well as in the strain bleached by streptomycin, have been identified by the conventional paper chromatographic method.

Variations have been observed when the photosynthetic apparatus is lost. Generally in the photosynthetic Euglena cells the pool of aminoacids reminds that of green algae, whereas bleached cells are similar to protozoa. It is possible that these variations are linked to the metabolic patways of green and bleached forms.     

A COMPOSITE RATING OF ALGAE TOLERATING ORGANIC POLLUTION2

From information on pollution-tolerant algae compiled from reports from 165 authors, the genera and species most often referred to as significant fall into a relatively stable series. Diatoms, pigmented flagellates, green, and blue-green algae are all well represented among the pollution-tolerant genera and species. The top 8 genera are Euglena, Oscillatoria, Chlamydomonas, Scenedesmus, Chlorella, Nitzschia, Navicula, and Stigeoclonium, and the top 5 species, Euglena viridis, Nitzschia palea, Oscillatoria limosa, Scenedesmus quadricauda, and Oscillatoria tennis. In some genera, e.g., Euglena, a single species is far more significant than all others as a pollution-tolerant form. In other genera, e.g., Oscillatoria, only a slight difference distinguishes the pollution tolerance of 2 or more species. Algal genus and species pollution indices arc presented for use in rating water samples with high organic pollution.     

Furan derivatives their common molecular denominator responsible for bleaching of Euglena gracilis

Summary We studied the effect of 38 furan derivatives on the green micro-organism Euglena gracilis and on Bacillus subtilis and Escherichia coli, with the aim of finding the common molecular denominator responsible for bleaching of Euglena gracilis by furan derivatives. The results confirmed that the nitro-group in position 5 of the furan nucleus is essential to the bleaching activity of these derivatives. It was also found, however, that the substituent in position 2 of the furan nucleus was likewise important. Only 5-nitrofuran derivatives with a –CH=N–linkage in position 2 of the furan nucleus (Schiff bases) are active bleachers. Derivatives with a –CH=CH– linkage are weak bleachers and derivatives with a thiourea at this site have no bleaching activity at all. All 5-nitrofurans and some bromo- or iodo-furans were active against Bacillus subtilis, but not one of the tested derivatives was active against Escherichia coli.     

Beta-Oxidation in Glyoxysomes from Euglena*

SYNOPSIS. We demonstrated previously the presence of glyoxysomes containing the glyoxylate cycle enzymes in Euglena gracilis grown in the dark on ethanol. We have now established that the glyoxysomes of Euglena grown on hexanoate also contain the following enzymes of the pathway for β-oxidation of fatty acids: hexanoyl-CoA synthetase, 3-β-hydroxyacyl-CoA dehydrogenase and thiolase. Estimations of specific activities indicate that these enzymes are over 20 times as active in glyoxysomes as they are in mitochondria, suggesting that the β-oxidation of fatty acids occurs almost entirely in Euglena glyoxysomes under these conditions. Thus, the entire portion of the gluconeogenic pathway from fatty acid to succinate is localized in the glyoxysome of Euglena.     

Surface properties and intracellular speciation revealed an original adaptive mechanism to arsenic in the acid mine drainage bio-indicator Euglena mutabilis

Euglena mutabilis is a protist ubiquitously found in extreme environments such as acid mine drainages which are often rich in arsenic. The response of E. mutabilis to this metalloid was compared to that of Euglena gracilis, a protist not found in such environments. Membrane fatty acid composition, cell surface properties, arsenic accumulation kinetics, and intracellular arsenic speciation were determined. The results revealed a modification in fatty acid composition leading to an increased membrane fluidity in both Euglena species under sublethal arsenic concentrations exposure. This increased membrane fluidity correlated to an induced gliding motility observed in E. mutabilis in the presence of this metalloid but did not affect the flagellar dependent motility of E. gracilis. Moreover, when compared to E. gracilis, E. mutabilis showed highly hydrophobic cell surface properties and a higher tolerance to water-soluble arsenical compounds but not to hydrophobic ones. Finally, E. mutabilis showed a lower accumulation of total arsenic in the intracellular compartment and an absence of arsenic methylated species in contrast to E. gracilis. Taken together, our results revealed the existence of a specific arsenical response of E. mutabilis that may play a role in its hypertolerance to this toxic metalloid.     

Comparaison, à la lumière et à l'obscurité, des synthèses spécifiques d'ARN chez Euglena gracilis Z en cultures synchrones sur milieu lactate et étude du Chondriome

Summary Synchronization of Euglena gracilis (Z) on lactate medium is shown to be independent of illumination. The existence of a mitochondrial cycle in lightgrown as well as in dark-grown Euglena is demonstrated. When RNA synthesis is studied by pulse labeling with tritiated uracil in synchronously growing cells, a discontinuous RNA synthesis is found. Two peaks of preferential RNA synthesis in dark-grown cells and three peaks in light-grown cells are seen; the significance of the third peak of RNA synthesis in light-grown Euglena is discussed.