''Coccomyxa'' 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 Coccomyxaceae. This genus is defined by their small, elliptical to spherical shape, and the presence of a simple 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 ...

. These features, along with their occurrence in various lifestyles such as free-living,

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

, or as , have been used to identify more than 40 species. Using additional morphological features, such as brown akinetes formation, allows for the differentiation between ''Coccomyxa'' and the genus ''Pseudococcomyxa'', as they tend to share some morphological characteristics like the general cell shape and one-sided mucilage cap. Recent molecular analysis, however, indicates that the genus ''Pseudococcomyxa'' is contained within different ''Coccomyxa'' clades, signaling the fact that the two genera are the same. ''Coccomyxa'' has often been used as a

model organism A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mo ...

, and its

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

is being completely sequenced. The genus is also an attractive candidate for

biofuel Biofuel is a fuel that is produced over a short time span from Biomass (energy), biomass, rather than by the very slow natural processes involved in the formation of fossil fuels such as oil. Biofuel can be produced from plants or from agricu ...

Etymology

''Coccomyxa'' is a combination of two Greco-Latin roots, cocco- and -myxa. Cocco- is a Latinized form of the Greek word ''kokkos'', meaning “berry”, or “seed”. This is in regards to shape, referencing that the ''Coccomyxa'' takes on an elliptical and globular structure. -myxa is a Greek term meaning “mucus”, in reference to ''Coccomyxa''’s production of mucoid substances.

Morphology

''Coccomyxa'' species are relatively small in size, measuring at about 6-14 by 3-6 μm and green in colour due to the presence of chlorophyll a and b. These green algae are elliptical to globular. Their cell wall varies in thickness, from about 40-100 nm, and the cup-shaped chloroplast makes up about half of the volume of the cell. Starch grains are located around the thylakoids. The genus ''Coccomyxa'' has a simple parietal chloroplast, but lacks a

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 ...

and flagellated stages. ''Coccomyxa'' are haplontic, meaning they spend a majority of their life cycles as haploids, and generally reproduce asexually. Reproduction occurs by the formation of 2 or 4 (sometimes up to 8)

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 ...

Habitat and ecology

''Coccomyxa'' has a worldwide distribution, and are able to form

biofilm A biofilm is a Syntrophy, syntrophic Microbial consortium, community of microorganisms in which cell (biology), cells cell adhesion, stick to each other and often also to a surface. These adherent cells become embedded within a slimy ext ...

s, inhabiting both marine and freshwater environments. They can be dominant in certain ecosystems and display an impressive diversity in habitat, possessing lifestyles that range from free-living to parasitic. ''Coccomyxa'' has been recorded free-living in terrestrial biofilms, as soil algae, connected with mosses, planktonic in limnic ecosystems, in symbiotic associations with fungi and higher plants, and parasitic to marine mussels. There is, however, no current studies that show ''Coccomyxa'' free-living in marine environments. Green algae have been shown to play a significant role in ecosystems. A species of ''Coccomyxa'', ''Coccomyxa parasitica'', has been noted as parasitizing the wild mussels from the Vigo estuary in Galicia, Spain. The aggregations of the green algae occur in the mantle, gill filaments, adductor muscle, visceral mass, and haemolymph of the species ''M. galloprovincialis''. Species of ''Coccomyxa'' are partners in many

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

Practical importance

''Coccomyxa'' is often used as a

, as its entire genome sequence has been published. This allows for further research as ''Coccomyxa'' can serve as a frame of reference or for further experimentation. Additionally, a free living ''Coccomyxa'' species, ''Coccomyxa'' sp.C-169, was suggested to be used for biofuels, as their enzyme-digestable cell wall and lipid production gained traction for research use above other strains.

Species list

* '' C. actinabiotis'' * '' C. arvernensis'' * '' C. astericola'' * '' C. brevis'' * '' C. chodatii'' * '' C. confluens'' * '' C. corbierei'' * '' C. curvata'' * C. dispar * '' C. elongata'' * C. flava * C. galuniael * C. glaronensis * '' C. gloeobotrydiformis'' * C. icmadophilae * '' C. litoralis'' * C. melkonianii * '' C. mucigena'' * C. naegeliana * '' C. olivacea'' * '' C. ophiura'' *

C. ovalis C. or c. may refer to: * Century, sometimes abbreviated as ''c.'' or ''C.'', a period of 100 years * Letter C, the third letter in the alphabet. * Cent (currency), abbreviated ''c.'' or ''¢'', a monetary unit that equals of the basic unit of man ...

* C. pallescens * '' C. parasitica'' * '' C. peltigerae'' * C. peltigerae variolosae * C. polymorpha * '' C. rayssiae'' * C. scabra * '' C. solorinae'' * '' C. solorinae bisporae'' * '' C. solorinae saccatae'' * '' C. solorinae-crocae'' * '' C. subellipsoida'' * '' C. subglobosa'' *

C. subsphaerica C. or c. may refer to: * Century, sometimes abbreviated as ''c.'' or ''C.'', a period of 100 years * Letter C, the third letter in the alphabet. * Cent (currency), abbreviated ''c.'' or ''¢'', a monetary unit that equals of the basic unit of man ...

* C. terrestris * C. thallosa * C. vinatzeri * '' C. viridis''

References

External links

AlgaTerra database

Index Nominum Genericorum
{{Taxonbar, from=Q310363 Trebouxiophyceae genera Enigmatic algae taxa