Euglena

Abstract

Euglena is a genus of single‐celled, free‐living microorganisms that show both plant‐ and animal‐like characteristics. Members of the genus are found widely in nature and mainly in fresh waters. Most are aerobic and use photosynthesis or many organic compounds as interchangeable sources of carbon and energy. The most studied species is the easily grown E. gracilis which, in spite of its relatively rigid surface, can be subfractionated to yield nuclei, mitochondria, chloroplasts, flagella and pellicles. Subfractions show some unusual characteristics: The nuclear envelope remains intact throughout mitosis and chromosomes are permanently condensed at all phases of the cell cycle, the mitochondrial respiratory chain has two terminal oxidases, and chloroplasts have three membranes reflecting their endosymbiotic evolutionary history. Various Euglena and some of their constituent molecules are useful for environmental biomediation and potentially useful biomedically.

Key Concepts:

  • Euglena is a genus of single‐celled, free living microorganisms that show both plant‐ and animal‐like characteristics.

  • More than 250 Euglena species have been described, though the actual number is not known.

  • The majority of Euglena species are green due to the presence of chloroplasts containing chlorophylls a and b.

  • Members of the genus Euglena are found widely in nature, inhabiting freshwater pools, ponds and lakes.

  • Euglena are able to use photosynthesis and heterotrophic oxidative assimilation as interchangeable and apparently equivalent sources of carbon and energy.

  • How to classify Euglena has been a long‐standing problem; the genus has been claimed as photosynthetic protozoa by zoologists and as algae by botanists.

  • Studies on the genus Euglena, and especially E. gracilis, have been significant for understanding the biochemistry and molecular biology of nuclei and subcellular organisms.

Keywords: single‐celled microorganism; free‐living; taxonomy; nucleus; mitochondrion; chloroplast; bioremediation

Figure 1.

A Euglena cell of the Euglena gracilis type showing the main organelles. From Leedale .

close

References

Ahmadinejad N, Dagan T and Martin W (2007) Genome history in the hybrid Euglena gracilis. Gene 402: 35–39.

Archibald JM and Keeling PJ (2002) Recycled plastids; a ‘green movement’ in eukaryotic evolution. Trends in Genetics 18: 577–584.

Buetow DE (ed.) (1968–1989) The Biology of Euglena, vols. I–IV. New York: Academic Press.

Buetow DE (1989) The mitochondrion. In: Buetow DE (ed.) The Biology of Euglema, vol. IV, pp. 247–314. San Diego: Academic Press.

Chae SR, Hwang ET and Shin HS (2006) Single cell protein production of Euglena gracilis and carbon dioxide fixation in an innovative photo‐bioreactor. Bioresource Technology 97: 322–329.

Cook JR (1968) The Cultivation and Growth of Euglena. In: Buetow DE (ed.) The Biology of Euglena, vol. I, pp. 243–314. New York: Academic Press.

Devars S, Hernandez R, Covian R et al. (1998) The content of alternative oxidase of Euglena mitochondria is increased by growth in the presence of cyanide and is not cytochrome O. Journal of Eukaryotic Microbiology 45: 122–130.

Ehrenberg CG (1830) Neue Beobachtungen über blutartige Erscheinungen in Ägypten, Arabien und Sibirien, nebst einer Übersicht und Kritik der früher bekannten. Poggendorff's Annalen der Physik und Chemie 94: 477–514.

Frantz C, Ebel C, Paulus F and Imbault P (2000) Characterization of trans‐splicing in Euglenoids. Current Genetics 37: 4738–4746.

Gawryluk RMR and Gray MW (2009) A split and rearranged nuclear gene encoding the iron‐sulfur subunit of mitochondrial succinate dehydrogenese in Euglenozoa. BMC Research Notes 2: 16–22.

Gibbs SP (1978) The chloroplast of Euglena may have evolved from symbiotic green algae. Canadian Journal of Botany 56: 2883–2889.

de Godos I, Vargas VA, Blanco S et al. (2010) A comparative evaluation of microalgae for the degradation of piggery wastewater under photosynthetic oxygenation. Biosource Technology 101: 5150–5158.

Green AG (2004) From alpha to omega – producing essential fatty acids in plants. Nature Biotechnology 22: 680–682.

Gupta S and Agrawal SC (2005) Motility and survival of Euglena ignobilis as affected by different factors. Folia Microbiologica 50: 315–322.

Hallick RB, Hong L, Drager RG et al. (1993) Complete sequence of Euglena gracilis chloroplast DNA. Nucleic Acids Research 21: 3537–3544.

Hayashi H, Wada S, Funayama T et al. (2004) Evaluation of the resistance of Euglena gracilis to ion beam radiation. Journal of Eukaryotic Microbiology 51: 321–324.

Hoffmeister M, van der Klei A, Rotte C et al. (2004) Euglena gracilis rhodoquinone: ubiquinone ratio and mitochondrial proteome differ under aerobic and anaerobic conditions. Journal of Biological Chemistry 279: 22422–22429.

Hosoya K and Kitaoka S (1977) Determination of the nutritive value of Euglena gracilis protein by in vitro digestion experiments and rat feeding tests. Journal of the Agricultural Chemistry Society of Japan 51: 483–488.

Ishii N and Uchida S (2006) Removal of technium from solution by the algal flagellate Euglena gracilis. Journal of Environmental Quality 35: 2017–2020.

Kitaoka S, Nakano Y, Miyatake K and Yokota A (1989) Enzymes and their functional location. In: Buetow DE (ed.) The Biology of Euglena, vol. IV, pp. 1–135. San Diego: Academic Press.

Lacky JB (1968) Ecology of Euglena. In: Buetow DE (ed.) The Biology of Euglena, vol. I, pp. 27–44. New York: Academic Press.

Leedale GF (1967) Euglenoid Flagellates. Englewood Cliffs, NJ: Prentice‐Hall.

Leedale GF (1982) Ultrastructure. In: Buetow DE (ed.) The Biology of Euglena, vol. III, pp. 1–27. New York: Academic Press.

Linton EW, Karnkowska‐Ishikawa A, Kim JI et al. (2010) Reconstructing Euglenoid evolutionary relationships using three genes: nuclear SSU and LSU, and chloroplast SSU rDNA sequences and the description of Eugleneria gen. nov. (Euglenophyta). Protist 161: 603–619.

Murakami T (1985) Effects of three kinds of single cell proteins on blood pressure, cerebral stroke lesions and hypertensive vascular changes in SHRSP. Acta Medica Kinki University 10: 51–71.

Ogbonna JC (2009) Microbiological production of tocopherols: current state and prospects. Applied Microbiology and Biotechnology 84: 217–225.

Ono K, Kondo M, Osafune T et al. (2003) Presence of glyoxylate cycle enzymes in the mitochondria of Euglena gracilis. Journal of Eukaryotic Microbiology 50: 92–96.

Patton NJ, Durnford DG and Kopriva S (2008) Sulfate assimilation in eukaryotes: fusions, relocations and lateral transfers. BMC Evolutionary Biology 8: 39–52.

Rodriguez‐Zavala JS, Garcia‐Garcia JD, Ortiz‐Cruz MA and Moreno‐Sanchez R (2007) Molecular mechanisms of resistance to heavy metals in the protist Euglena gracilis. Journal of Environmental Science and Health Part A 42: 1365–1378.

Saidha T, Na SQ, Li JY and Schiff JA (1988) A sulfate metabolizing centre in Euglena mitochondria. Biochemical Journal 253: 533–539.

Schiff JA and Schwartzbach SD (1982) Photocontrol of chloroplast development. In: Buetow DE (ed.) The Biology of Euglena, vol. III, pp. 314–352. New York: Academic Press.

Sittenfeld A, Marielos M, Ortega JM et al. (2002) Characterization of a photosynthetic Euglena strain isolated from an acidic hot mud pool of a volcanic area of Costa Rica. FEMS Microbiology Ecology 42: 151–160.

Sláviková S, Vacula R, Fang Z et al. (2005) Homologous and heterologous reconstitution of Golgi to chloroplast transport and protein import into the complex chloroplasts of Euglena. Journal of Cell Science 118: 1651–1661.

Sogin ML, Elwood HJ and Gunderson JH (1986) Evolutionary diversity of eukaryotic small‐subunit rRNA genes. Proceedings of the National Academy of Sciences of the USA 83: 1383–1387.

Sugiyama A, Hata S, Suzuki K et al. (2010) Oral administration of paramylon, a β‐1,3‐d‐glucan isolated from Euglena gracilis Z inhibits development of atopic dermatitis‐like skin lesions from NC/Nga micE. Journal of Veterinary Medical Science 72: 755–763.

Sugiyama A, Suzuki K, Mitra S et al. (2009) Hepatoprotective effects of paramylon, a β‐1,3‐d‐glucan isolated from Euglena gracilis Z, on acute liver injury induced by carbon tetrachloride in rats. Journal of Veterinary Medical Science 71: 885–890.

Sulli C and Schwartzbach SD (1996) A soluble protein is imported into Euglena chloroplasts as a membrane‐bound precursor. Plant Cell 8: 43–53.

Tani Y, Okumura M and Li S (1987) Liquid wax ester production by Euglena gracilis. Agricultural and Biological Chemistry 51: 225–230.

Tani Y and Tsumura H (1989) Screening for tocopherol‐producing microorganisms and a‐tocopherol production by Euglena gracilis Z. Agricultural and Biological Chemistry 53: 305–312.

Tessier L‐H, Keller M, Chan RL et al. (1991) Short leader sequences may be transferred from small RNAs to premature mRNAs by trans‐splicing in Euglena. EMBO Journal 10: 2621–2625.

Von der Heyden S, Chao EE, Vickerman K and Cavalier‐Smith T (2004) Ribsomal RNA phylogeny of bodonid and diplonemid flagellates and the evolution of Euglenozoa. Journal of Eukaryotic Microbiology 51: 402–416.

Waygood ER, Hussain A, Godavari HR, Tai YC and Badour SS (1980) Purification and reclamation of farm and urban wastes by Euglena gracilis: photosynthetic capacity, effect of pH, temperature, acetate and whey. Environmental Pollution 23(Series A): 179–215.

Zimba PV, Moeller PD, Beauchesne K et al. (2010) Identification of euglenophycin – a toxin found in certain euglenoids. Toxicon 55: 100–104.

Further Reading

Ciugulea I and Triemer RE (2010) A Color Atlas of Photosynthetic Euglenoids. East Lansing: Michigan State University Press.

Gojdics M (1953) The Genus Euglena. Madison: The University of Wisconson Press.

Kitaoka S (1989) Euglena‐Physiology and Biochemistry. Tokyo: Gakkai Shuppan Center. [In Japanese].

Leedale GF (1971) The Euglenoids. Oxford Biology Readers. London: Oxford University Press.

Leedale GF (2000) Euglenozoa. In: Lee JJ, Leedale GF and Bradbury P (eds) An Illustrated Guide to the Protozoa, 2nd edn, vol. II, pp. 1135–1185. Lawrence, KS: Allen Press, Inc.

Sleigh M (1989) Protozoa and Other Protists. London: Edward Arnold.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Buetow, Dennis E(Apr 2011) Euglena. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001964.pub3]