''Coelastrella'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

green algae The green algae (: green alga) 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 ...

in the family

Scenedesmaceae Scenedesmaceae is a family of green algae in the order Sphaeropleales. ''Scenedesmus'' algae are commonly found in freshwater plankton. The former family Coelastraceae is considered a synonym of Scenedesmaceae. The family has existed since at ...

.See the

NCBI The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is loca ...

br>webpage on Coelastrella
Data extracted from the It is currently classified in the subfamily Coelastroideae. ''Coelastrella'' consists of solitary cells or clusters of a few cells. Cells are spherical to ellipsoidal or lemon-shaped, and are surrounded by a hyaline or brownish

cell wall A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, ...

with 4 to 40 longitudinal striations. Cells contain numerous conspicuous

vacuole A vacuole () is a membrane-bound organelle which is present in Plant cell, plant and Fungus, fungal Cell (biology), cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water ...

s. Each cell contains one

nucleus Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleu ...

and a single parietal

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

, each with one

pyrenoid Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ...

. When mature, cultures may form a deep red color due to the presence of pigments in the cells. A distinctive identifying feature of ''Coelastrella'' are the longitudinal striations on the cell walls. These are often only visible under

scanning electron microscopy A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that ...

(SEM). Due to the scarcity of morphological characteristics visible under light microscopy, species of this genus have generally been overlooked. ''Coelastrella'' reproduces asexually by the formation of

autospore Autospores are a type of spores that are produced by algae to enable asexual reproduction and spread. They are non-motile and non-Flagellated cell, flagellated Aplanospore, aplanospores that are generated within a parent cell and have the same sha ...

s, which are released by a tear in the mother cell wall. ''Coelastrella'' has not been observed to undergo sexual reproduction, or exhibit life stages with

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

Habitat

''Coelastrella'' species are distributed all around the world, from the tropics to the poles. They mostly occupy aerophytic habitats, such as soils, tree trunks, and on rocks. They also inhabit freshwater habitats. One strain of ''Coelastrella'' is thermotolerant and can withstand temperatures of 50 °C for over eight hours.

Taxonomy

The genus ''Coelastrella'' includes species formerly included in the genus ''Scotiellopsis''. Species classified ''Scotiella'' were distinguished by their lemon-shaped cells and fewer longitudinal ribs. However, molecular data demonstrated that the two genera were conspecific. The taxonomic status of one species, ''Scotiellopsis levicostata'', is unclear because there is no known strain for this species.

Biotechnology

''Coelastrella'' strains are the subject of recent research, because they produce high amounts of useful compounds. ''Coelastrella'' is typically grown on Bold's basal medium (BBM). Examples of useful products of ''Coelastrella'' species include

carotenoid Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...

s suchas

astaxanthin Astaxanthin is a keto- carotenoid within a group of chemical compounds known as carotenoids or terpenes. Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-solu ...

, or lipids such as

linoleic acid Linoleic acid (LA) is an organic compound with the formula . Both alkene groups () are ''cis''. It is a fatty acid sometimes denoted 18:2 (n−6) or 18:2 ''cis''-9,12. A linoleate is a salt or ester of this acid. Linoleic acid is a polyunsat ...

. The lipids may also be used for

bioenergy Bioenergy is a type of renewable energy that is derived from plants and animal waste. The Biomass (energy), biomass that is used as input materials consists of recently living (but now dead) organisms, mainly plants. Thus, Fossil fuel, fossil fu ...

purposes. In addition to chemical production, ''Coelastrella'' has capacity for

bioremediation Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi in mycoremediation, and plants in phytoremediation), living or dead, is employed for removing environmental pollutants from air, wate ...

or wastewater treatment.

References

{{Taxonbar, from=Q5140587 Sphaeropleales genera Sphaeropleales