Elliptochloris bilobata

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Elliptochloris bilobata
Patova et al 2023 5d Elliptochloris bilobata.png
Scientific classification OOjs UI icon edit-ltr.svg
Clade: Viridiplantae
Division: Chlorophyta
Class: Trebouxiophyceae
Order: Prasiolales
Family: incertae sedis
Genus: Elliptochloris
Species:
E. bilobata
Binomial name
Elliptochloris bilobata

Elliptochloris bilobata is a species of green alga in the order Prasiolales. First described in 1980, it is the type species of the genus Elliptochloris . The microscopic alga has distinctive ellipsoid cells containing a unique bilobed chloroplast, and reproduces both through autospores and rod-shaped spores. Though originally discovered as a photobiont within the lichen Catolechia wahlenbergii in the Austrian Alps, it has since been found living freely across Europe, Israel, and Antarctica. The species grows on various surfaces including soil, rock, and tree bark, and is known for its ability to grow in both natural and human-modified environments.

Contents

Taxonomy

Elliptochloris bilobata was first formally described by Elisabeth Tschermak-Woess in 1980. The discovery began when Josef Hafellner collected lichen specimens in July 1978 from Knotenberg mountain, Austria. Tschermak-Woess then worked to isolate the algal component from these lichen fragments, initially facing several challenges. After multiple attempts, she successfully established six clonal cultures, allowing for detailed study of the organism. [1]

The discovery represented not only a new species but also a new genus, as the organism's unique characteristics set it apart from all known green algae at the time. The species was particularly significant to algal taxonomy because it challenged the traditional classification of Chlorococcales, which were typically divided into groups based on whether they reproduced via autospores or zoospores – E. bilobata exhibited characteristics that bridged these categories. [1] It is the type species of the genus Elliptochloris . The species name bilobata comes from Latin, meaning "with two lobes" or "bilobed". [2]

The type specimen was collected from Knotenberg in the Kreuzeck mountain range, Carinthia, Austria, where it was found living as a phycobiont (algal symbiont) in the lichen Catolechia wahlenbergii . The authentic strain SAG 245.80, which is cryopreserved in a metabolically inactive state, was later designated as the epitype by Darienko and Pröschold in 2016. Type specimens are preserved at both the University of Graz (GZU) and the University of Vienna (WU) herbaria. [2]

Description

Elliptochloris bilobata is a microscopic green alga with distinctive cellular features. The cells are typically ellipsoid in form, though they can sometimes be spherical. Individual cells measure up to 13  μm in length and 10.5 μm in width, about the size of a small human red blood cell. [1]

The most distinctive feature of the species is its unique chloroplast (the cell's photosynthetic structure), which is divided into two lobes connected by a narrow bridge. This bilobed chloroplast has a trough-like or cup-like shape and typically lies against the cell wall, leaving part of the cell's interior space free. The cell's nucleus is typically positioned near the base of this trough-shaped chloroplast. Unlike many related algae, E. bilobata lacks pyrenoids (protein bodies typically involved in carbon fixation), but stores starch in very small, flat granules. The cell's cytoplasm (internal cellular fluid) has a characteristic honeycomb-like or alveolar appearance, containing numerous small vacuoles that give it a spongy texture and small droplets of oil. The cell is enclosed by a thin but firm cell wall. [1]

When dividing, the cell follows a precise sequence: the chloroplast splits first at its bridge-like connection, followed by the division of the nucleus and finally the cell itself. The species employs two distinct reproductive strategies. The first method involves producing autospores, which are daughter cells that closely resemble the parent cell in shape and structure, typically forming two to four new cells. The second method produces much smaller rod-shaped spores, with a single parent cell giving rise to either 16 or 32 tiny rod-like cells measuring between 2 and 8.5 micrometres in length. These rod-shaped spores eventually grow and develop into the typical ellipsoid form of mature cells. [1]

Elliptochloris bilobata is the photobiont partner of the lichen Catolechia wahlenbergii, shown here. Goblins Lantern (3849766223).jpg
Elliptochloris bilobata is the photobiont partner of the lichen Catolechia wahlenbergii, shown here.

This alga was first discovered living symbiotically as a photobiont within the lichen Catolechia wahlenbergii, where it provides energy through photosynthesis to support the fungal partner. The species has been successfully grown in laboratory cultures, where it forms pale green colonies that can have a somewhat watery-mucilaginous texture. In laboratory settings, it grows best at pH 5 and can be cultivated under alternating cycles of light and dark (16 hours of light followed by 8 hours of darkness) at temperatures between 17–21°C. [1]

Distribution, habitat, and ecology

Elliptochloris bilobata was first discovered in the Austrian Alps, where it was found living symbiotically within the lichen Catolechia wahlenbergii. The type locality is Knotenberg mountain in the Kreuzeck range, Carinthia, Austria, at an elevation of approximately 2,200 metres above sea level. [1] Since its initial discovery, the species has been reported across Europe, including in Bulgaria, the Czech Republic, Russia, Ukraine, and the Ural Mountains. Outside Europe, it has been found in Israel and Antarctica. [2]

The species inhabits a wide range of environments, being particularly common in forest soils [3] and tundra regions. [4] [5] While it has been documented in various climatic zones, including Antarctic environments, [6] [7] it is absent from desert habitats. [8]

The alga grows on diverse substrates, including granite outcrops, tree bark, and in caves. [9] On granite surfaces, it can form visible macroscopic growths and often becomes the dominant algal species. [8]

Elliptochloris bilobata demonstrates considerable adaptability to human-modified environments, showing tolerance to various forms of air pollution. This environmental flexibility, combined with its ability to form lichen symbioses while also surviving independently, makes it one of the more successful species in both natural and anthropogenically altered habitats. [8]

Related Research Articles

<span class="mw-page-title-main">Algae</span> Diverse group of photosynthetic eukaryotic organisms

Algae is an informal term for any organisms of a large and diverse group of photosynthetic eukaryotes, which include species from multiple distinct clades. Such organisms range from unicellular microalgae such as Chlorella, Prototheca and the diatoms, to multicellular macroalgae such as the giant kelp, a large brown alga which may grow up to 50 metres (160 ft) in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton.

<span class="mw-page-title-main">Chlorophyceae</span> Class of green algae

The Chlorophyceae are one of the classes of green algae, distinguished mainly on the basis of ultrastructural morphology. They are usually green due to the dominance of pigments chlorophyll a and chlorophyll b. The chloroplast may be discoid, plate-like, reticulate, cup-shaped, spiral- or ribbon-shaped in different species. Most of the members have one or more storage bodies called pyrenoids located in the chloroplast. Pyrenoids contain protein besides starch. Some green algae may store food in the form of oil droplets. They usually have a cell wall made up of an inner layer of cellulose and outer layer of pectose.

<span class="mw-page-title-main">Chlorophyta</span> Phylum of green algae

Chlorophyta is a division of green algae informally called chlorophytes.

<span class="mw-page-title-main">Lichen</span> Symbiosis of fungi with algae or cyanobacteria

A lichen is a hybrid colony of algae or cyanobacteria living symbiotically among filaments of multiple fungi species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualistic relationship. Lichens are the lifeform that first brought the term symbiosis under biological context.

<span class="mw-page-title-main">Green algae</span> Paraphyletic group of eukaryotes

The green algae are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as a sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid (spherical), and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae, many of which live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds.

<i>Chlamydomonas nivalis</i> Species of alga

Chlamydomonas nivalis, also referred to as Chloromonas typhlos, is a unicellular red-coloured photosynthetic green alga that is found in the snowfields of the alps and polar regions all over the world. They are one of the main algae responsible for causing the phenomenon of watermelon snow, where patches of snow appear red or pink. The first account of microbial communities that form red snow was made by Aristotle. Researchers have been active in studying this organism for over 100 years.

<i>Desmodesmus</i> Genus of algae

Desmodesmus is a genus of green algae in the family Scenedesmaceae. It is the only chlorophyll-containing organism known to have caused human infections in immunocompetent individuals. All known cases involved open injuries occurring in fresh water.

Dictyochloropsis is a genus of unicellular green alga of the phylum Chlorophyta. This genus consists of free-living algae which have a reticulate (net-like) chloroplast that varies slightly in morphology between species, and that when mature always lacks a pyrenoid. Dictyochloropsis is asexual and reproduces using autospores.

<i>Planktosphaeria</i> Genus of algae

Planktosphaeria is a genus of Chlorophyceae of the green algae. It was first described by the phycologist Gilbert Morgan Smith in 1918, with Planktosphaeria gelatinosa as its type species. Species of Planktosphaeria are commonly found in freshwater plankton around the world.

Pseudomuriella is a genus of green algae, specifically of the class Chlorophyceae. It is the sole genus of the family Pseudomuriellaceae. It is a terrestrial alga that inhabits soils.

<i>Trebouxia</i> Genus of algae

Trebouxia is a unicellular green alga. It is a photosynthetic organism that can exist in almost all habitats found in polar, tropical, and temperate regions. It can either exist in a symbiotic relationship with fungi in the form of lichen or it can survive independently as a free-living organism alone or in colonies. Trebouxia is the most common photobiont in extant lichens. It is a primary producer of marine, freshwater and terrestrial ecosystems. It uses carotenoids and chlorophyll a and b to harvest energy from the sun and provide nutrients to various animals and insects.

Pseudodictyochloris is a genus of green algae, in the family Actinochloridaceae. It is found in soils.

<span class="mw-page-title-main">Autospore</span>

Autospores are a type of spores that are produced by algae to enable asexual reproduction and spread. They are non-motile and non-flagellated aplanospores that are generated within a parent cell and have the same shape as the parent cell before their release. Autospores are also known as resting spores. Algae primarily use three different types of spores for asexual reproduction - autospores, zoospores, and aplanospores. Autospores occur in several groups of algae, including Eustigmatophyceae, Dinoflagellates, and green algae. One example of a colonial alga that produces autospores is Dichotomococcus. This alga generates two autospores per reproducing cell, and the autospores escape through a slit in the cell wall and remain attached to the mother cell. Some study on autospores and algae in general include looking into its use for biofuel, animal feed, food supplements, nutraceuticals, and pharmaceuticals.

Elisabeth Tschermak-Woess was an Austrian University lecturer, cytologist, and phycologist who worked with lichen photobionts. In 1994, Tschermak-Woess was awarded the Acharius Medal for her lifetime contributions to lichenology. She had a Festschrift dedicated to her in 1988, in the journal Plant Systematics and Evolution. Lichen taxa that have been named after Tschermak-Woess include the genus Woessia and the species Asterochloris woessiae.

<i>Mastodia</i> Genus of lichens

Mastodia is a genus of lichen-forming fungi in the family Verrucariaceae. It has six species.

Trebouxia decolorans is a widespread and common symbiotic species of green alga that is found in association with different species of lichen-forming fungi. Some lichens in which it is the photobiont partner are Xanthoria parietina and Anaptychia ciliaris.

Trebouxia gelatinosa is a common symbiotic species of green alga in the family Trebouxiaceae. Formally described as new to science in 1975, it is usually found in association with different species of lichen-forming fungi.

Asterochloris is a genus of green algae in the family Trebouxiophyceae. It is a common photobiont in lichen, occurring in the thalli of more than 20 lichen genera worldwide. Asterochloris is distinguishable from the morphologically similar genus Trebouxia, primarily due to its deeply lobed chloroplast, the placement of the chloroplast along the cell's periphery before the initiation of zoospore or aplanospore formation, and its tendency to primarily reproduce asexually through the production of aplanospores.

<i>Normandina pulchella</i> Species of lichen

Normandina pulchella, commonly known as the elf-ear lichen or blue heart, is a species of squamulose lichen in the family Verrucariaceae. This cosmopolitan species is widely distributed across both hemispheres, where it thrives in moist microhabitats. It favours moss-covered deciduous trees and rocks, often colonising over mosses and bryophytes. It occasionally grows on bare bark and on other lichens. Distinctive features of N. pulchella include its bluish-green squamules (scales) with sharply raised margins, non-reactivity to standard chemical spot tests, and growth in humid habitats. Initially, Nannochloris normandinae, a green alga, was thought to be its photobiont. However, recent studies have revised this understanding, now suggesting Diplosphaera as the algal partner.

<i>Pseudocyphellaria carpoloma</i> Species of lichen

Pseudocyphellaria carpoloma is a species of corticolous (bark-dwelling), foliose lichen in the family Peltigeraceae. It is found in New Zealand, most commonly in northern coastal forest, but also on the west coast of South Island, on Stewart Island, and in the Kermadec Islands. The bright green upper surface, dichotomously branching nature of its lobes, as well as the yellow pseudocyphellae on the lobe margins and lower surface are characteristics that distinguish it from other New Zealand species in genus Pseudocyphellaria, such as P. billardierii, P. faveolata and P. rufovirescens.

References

  1. 1 2 3 4 5 6 7 Tschermak-Woess, Elisabeth (1980). "Elliptochloris bilobata, gen. et spec. nov., der Phycobiont von Catolechia wahlenbergii" [Elliptochloris bilobata, gen. and spec. nov., the phycobiont of Catolechia wahlenbergii]. Plant Systematics and Evolution (in German). 136 (1–2): 63–72. doi:10.1007/BF00985313.
  2. 1 2 3 Guiry, M.D.; Guiry, G.M. "Elliptochloris bilobata". AlgaeBase . World-wide electronic publication, National University of Ireland, Galway.
  3. ↑ Hoffmann, Lucien; Ector, Luc; Kostikov, Igor (2007). "Algal flora from limed and unlimed forest soils in the Ardenne (Belgium)". Systematics and Geography of Plants. 77: 15–90. doi:10.2307/20649729.
  4. ↑ Andreyeva, V.M. (2004). "Terrestrial nonmotile green algae (Chlorophyta) of Vorkuta tundra (Komi Republic)". Novosti sistematiki nizshikh rastenii (in Russian). 37: 3–8.
  5. ↑ Novakovskaya, I.V.; Dubrovskiy, Y.A.; Patova, E.N.; Novakovskiy, A.B.; Sterlyagova, I.N. (2020). "Influence of ecological factors on soil algae in different types of mountain tundra and sparse forests in the Northern Urals". Phycologia. 59: 320–329.
  6. ↑ González Garraza, G.; Mataloni, G.; Fermani, P.; Vinocur, A. (2011). "Ecology of algal communities of different soil types from Cierva Point, Antarctic Peninsula". Polar Biology. 34: 339–351. doi:10.1007/s00300-010-0887-8.
  7. ↑ Borchhardt, N.; Schiefelbein, U.; Abarca, N.; Boy, J.; Mikhailyuk, T. (2017). "Diversity of algae and lichens in biological soil crusts of Ardley and King George islands, Antarctica". Antarctic Science. 29: 229–237. doi:10.1017/S0954102016000638.
  8. 1 2 3 Veselá, Veronika; Malavasi, Veronica; Škaloud, Pavel (2024). "A synopsis of green-algal lichen symbionts with an emphasis on their free-living lifestyle". Phycologia. 63 (3): 317–338. doi: 10.1080/00318884.2024.2325329 .
  9. ↑ Vinogradova, O.N.; Nevo, Eviator; Wasser, Solomon P. (2009). "Algae of the Sefunim Cave (Israel): Species diversity affected by light, humidity and rock stresses". International Journal on Algae. 11 (2): 99–116. doi:10.1615/InterJAlgae.v11.i2.10.
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