Chlorella is a genus of about thirteen species of single-celled or colonial green algae of the division Chlorophyta. The cells are spherical in shape, about 2 to 10 μm in diameter, and are without flagella. Their chloroplasts contain the green photosynthetic pigments chlorophyll-a and -b. In ideal conditions cells of Chlorella multiply rapidly, requiring only carbon dioxide, water, sunlight, and a small amount of minerals to reproduce.
Propionibacterium is a gram-positive, anaerobic, rod-shaped genus of bacteria named for their unique metabolism: They are able to synthesize propionic acid by using unusual transcarboxylase enzymes.
Filamentous bacteriophages are a family of viruses (Inoviridae) that infect bacteria, or bacteriophages. They are named for their filamentous shape, a worm-like chain, about 6 nm in diameter and about 1000-2000 nm long. This distinctive shape reflects their method of replication: the coat of the virion comprises five types of viral protein, which are located in the inner membrane of the host bacterium during phage assembly, and these proteins are added to the nascent virion's DNA as it is extruded through the membrane. The simplicity of filamentous phages makes them an appealing model organism for research in molecular biology, and they have also shown promise as tools in nanotechnology and immunology.
Phycodnaviridae is a family of large (100–560 kb) double-stranded DNA viruses that infect marine or freshwater eukaryotic algae. Viruses within this family have a similar morphology, with an icosahedral capsid. As of 2014, there were 33 species in this family, divided among 6 genera. This family belongs to a super-group of large viruses known as nucleocytoplasmic large DNA viruses. Evidence was published in 2014 suggesting that specific strains of Phycodnaviridae might infect humans rather than just algal species, as was previously believed. Most genera under this family enter the host cell by cell receptor endocytosis and replicate in the nucleus. Phycodnaviridae play important ecological roles by regulating the growth and productivity of their algal hosts. Algal species such Heterosigma akashiwo and the genus Chrysochromulina can form dense blooms which can be damaging to fisheries, resulting in losses in the aquaculture industry. Heterosigma akashiwo virus (HaV) has been suggested for use as a microbial agent to prevent the recurrence of toxic red tides produced by this algal species. Phycodnaviridae cause death and lysis of freshwater and marine algal species, liberating organic carbon, nitrogen and phosphorus into the water, providing nutrients for the microbial loop.
Methanobacteriales is an order of archaeans in the class Methanobacteria. Species within this order differ from other methanogens in that they can use fewer catabolic substrates and have distinct morphological characteristics, lipid compositions, and RNA sequences. Their cell walls are composed of pseudomurein. Most species are Gram-positive with rod-shaped bodies and some can form long filaments. Most of them use formate to reduce carbon dioxide, but those of the genus Methanosphaera use hydrogen to reduce methanol to methane.
Methanothermobacter is a genus of archaeans in the family Methanobacteriaceae. The species within this genus are thermophilic and grow best at temperatures between 55 °C and 65 °C. They are methanogens; they use carbon dioxide and hydrogen as substrates to produce methane for energy.
Selenastraceae is a family of green algae in the order Sphaeropleales. Members of this family are common components of the phytoplankton in freshwater habitats worldwide. A few species have been found in brackish and marine habitats, such as in the Baltic Sea.
Auxenochlorella protothecoides, formerly known as Chlorella protothecoides, is a facultative heterotrophic green alga in the family Chlorellaceae. It is known for its potential application in biofuel production. It was first characterized as a distinct algal species in 1965, and has since been regarded as a separate genus from Chlorella due its need for thiamine for growth. Auxenochlorella species have been found in a wide variety of environments from acidic volcanic soil in Italy to the sap of poplar trees in the forests of Germany. Its use in industrial processes has been studied, as the high lipid content of the alga during heterotrophic growth is promising for biodiesel; its use in wastewater treatment has been investigated, as well.
Dicloster is a genus of green algae in the family Chlorellaceae, containing the sole species Dicloster acuatus. It is found in freshwater habitats as plankton, and is distributed around the world.
Didymogenes is a genus of microscopic green algae in the class Trebouxiophyceae. It is a planktonic species found in freshwater habitats worldwide. Formerly placed in the family Scenedesmaceae, molecular studies have placed it in the family Chlorellaceae.
Prototheca is a genus of algae in the family Chlorellaceae. While this genus is a member of the green algae, all Prototheca no longer have chloroplasts and therefore their photosynthetic ability. Some species can cause protothecosis in humans and various vertebrates.
Climacostomum is a genus of unicellular ciliates, belonging to the class Heterotrichea.
Chlorovirus, also known as Chlorella virus, is a genus of giant double-stranded DNA viruses, in the family Phycodnaviridae. This genus is found globally in freshwater environments where freshwater microscopic algae serve as natural hosts. There are 19 species in this genus.
Acanthocystis turfacea chlorella virus 1 (ATCV-1), also called Chlorovirus ATCV-1 or Chlorella virus ATCV-1 is a species of giant double-stranded DNA virus in the genus Chlorovirus.
Vampirovibrio chlorellavorus is a 0.6 μm pleomorphic coccus with a gram negative cell wall, and is one of the few known predatory bacteria. Unlike many bacteria, V. chlorellavorus is an obligate parasite, attaching to the cell wall of green algae of the genus Chlorella. The name Vampirovibrio originates from the Serbian vampir. meaning vampire and vibrio referring to the bacterial genus of curved rod bacterium. Chlorellavorus is named for the algal host of the bacterium (Chlorella) and the Latin voro meaning "to devour" (Chlorella-devouring).
Chlorella volutis is a species of euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped, is solitary and lacks a mucilaginous envelope.
Chlorella singularis is a species of euryhaline, unicellular microalgae. It is spherical to oval-shaped and is solitary.
Chlorella colonialis is a euryhaline, unicellular microalga in the Division Chlorophyta. It is spherical to oval-shaped and is solitary.
Marmoricola is a Gram-positive and chemoorganotrophic bacterial genus from the family of Nocardioidaceae.
Chlorella vulgaris is a species of green microalga in the division Chlorophyta. This unicellular alga was discovered in 1890 by Martinus Willem Beijerinck as the first microalga with a well-defined nucleus. It is the type species of the genus Chlorella. It is found in freshwater and terrestrial habitats, and has a cosmopolitan distribution.
