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.
Auxenochlorella pyrenoidosa, formerly Chlorella pyrenoidosa, is a species of the freshwater green alga in the Division Chlorophyta. It occurs worldwide. The species name pyrenoidosa refers to the presence of a prominent pyrenoid within the Chlorella chloroplast.
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.
Neochloris oleoabundans is a microalga belonging in the class Chlorophyceae. Due to its high lipid content, it has been considered as a candidate organism for cosmetics and biofuel production, as well as feed stock for freshwater mussels.
Scenedesmus is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile. They are one of the most common components of phytoplankton in freshwater habitats worldwide.
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.
Choricystis is a genus of green algae in the class Trebouxiophyceae, considered a characteristic picophytoplankton in freshwater ecosystems. Choricystis, especially the type species Choricystis minor, has been proposed as an effective source of fatty acids for biofuels. Choricystis algacultures have been shown to survive on wastewater. In particular, Choricystis has been proposed as a biological water treatment system for industrial waste produced by the processing of dairy goods.
Coelastrella is a genus of green algae in the family Scenedesmaceae. It is currently classified in the subfamily Coelastroideae.
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.
Lobosphaera is a genus of green algae in the family Trebouxiaceae. It was originally described from soils in Austria, but has since been found in freshwater habitats and as a symbiont within lichens.
Monoraphidium is a genus of green algae in the family Selenastraceae. Monoraphidium is found free-floating or attached to surfaces in water, or in soils. It is one of the most common types of phytoplankton in freshwater habitats, and has a cosmopolitan distribution.
Algae fuel, algal biofuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane. When made from seaweed (macroalgae) it can be known as seaweed fuel or seaweed oil. These fuels have no practical significance but remain an aspirational target in the biofuels research area.
Nannochloropsis is a genus of algae comprising six known species. The genus in the current taxonomic classification was first termed by Hibberd (1981). The species have mostly been known from the marine environment but also occur in fresh and brackish water. All of the species are small, nonmotile spheres which do not express any distinct morphological features that can be distinguished by either light or electron microscopy. The characterisation is mostly done by rbcL gene and 18S rRNA sequence analysis.
Microalgae or microscopic algae grow in either marine or freshwater systems. They are primary producers in the oceans that convert water and carbon dioxide to biomass and oxygen in the presence of sunlight.
Raphidocelis subcapitata, formerly known as Selenastrum capricornutum and Pseudokirchneriella subcapitata is a microalga. This microalga presents a curved and twisted appearance like a sickle. The cells are normally presented in a solitary form in culture, although it may also be present in small colonies. It has a length between 7 and 15 μm, and a width between 1.2 and 3 μm. A single chloroplast is present, filling nearly the entire cell; it lacks a pyrenoid. It is commonly used as a bioindicator species to assess the levels of nutrients or toxic substances in fresh water environments. This species is quite sensitive to the presence of toxic substances including metals and has a ubiquitous distribution, so is broadly used in ecotoxicology. This species has been found to be more competitive than Chlorella vulgaris at low sodium chloride concentrations, but C. vulgaris was more competitive under salt stress.
Gonyostomum semen is a species of freshwater algae in the genus Gonyostomum, with worldwide distribution. They cause nuisance algal blooms and are known to cause allergic reactions to people swimming in lakes.
Chlorella autotrophica, or Chlorella sp. (580), is a species of euryhaline, unicellular microalga in the Division Chlorophyta. It is found in brackish waters and was first isolated in 1956 by Ralph A. Lewin. The species is defined by its inability to use organic carbon as a food source, making the species an obligate autotroph. It is sometimes considered a variety of Chlorella vulgaris.
Tetradesmus obliquus is a green algae species of the family Scenedesmaceae. It is commonly known by its synonym, Scenedesmus obliquus. It is a common species found in a variety of freshwater habitats.
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.
