Algae is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as Chlorella,Prototheca and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to 50 metres (160 ft) in length. Most are aquatic and autotrophic 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, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, Spirogyra and stoneworts.
Chlamydomonas is a genus of green algae consisting of about 150 species all unicellular flagellates, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "snow algae". Chlamydomonas is used as a model organism for molecular biology, especially studies of flagellar motility and chloroplast dynamics, biogenesis, and genetics. One of the many striking features of Chlamydomonas is that it contains ion channels (channelrhodopsins) that are directly activated by light. Some regulatory systems of Chlamydomonas are more complex than their homologs in Gymnosperms, with evolutionarily related regulatory proteins being larger and containing additional domains.
Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO2) fixation, by generating and maintaining a CO2 rich environment around the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria.
Chlamydomonas reinhardtii is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and an eyespot that senses light.
Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist individually, or in chains or groups. Depending on the species, their sizes can range from a few micrometers (μm) to a few hundred micrometers. Unlike higher plants, microalgae do not have roots, stems, or leaves. They are specially adapted to an environment dominated by viscous forces.
Algaculture is a form of aquaculture involving the farming of species of algae.
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.
The Aquatic Species Program was a research program in the United States launched in 1978 by President Jimmy Carter and was funded by the United States Department of Energy, which over the course of nearly two decades looked into the production of energy using algae. Initially, the funding of the Aquatic Species Program was to develop renewable fuel for transportation. Later, the program focused on producing bio-diesel from algae. The research program was discontinued in 1996. The research staff compiled their work and conclusions into a 1998 report.
Biohydrogen is H2 that is produced biologically. Interest is high in this technology because H2 is a clean fuel and can be readily produced from certain kinds of biomass.
Scenedesmus is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile.
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.
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.
TerraVia Holdings, Inc. was a publicly held biotechnology company in the United States. TerraVia used proprietary technology to transform a range of low-cost plant-based sugars into high-value oils and whole algae ingredients. TerraVia supplied a variety of sustainable algae-based food ingredients to a number of brands, which included Hormel Food Corporation, Utz Quality Foods Inc., and Enjoy Life Foods. TerraVia also sold its own culinary algae oil under the Thrive Algae Oil brand.
Sapphire Energy was a San Diego-based American energy company that aimed to produce crude oil with algae.
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.
Algae fuel in the United States, as with other countries, is under study as a source of biofuel.
Nannochloropsis is a genus of alga within the heterokont line of eukaryotes, that is being investigated for biofuel production. One marine Nannochloropsis species has been shown to be suitable for algal biofuel production due to its ease of growth and high oil content, mainly unsaturated fatty acids and a significant percentage of palmitic acid. It also contains enough unsaturated fatty acid linolenic acid and polyunsaturated acid for a quality biodiesel.
Michael Melkonian is a German botanist and professor of botany at the University of Cologne.
Alison Gail Smith, Lady Hopper is Professor of Plant Biochemistry in the Department of Plant Sciences at the University of Cambridge, UK. Her research investigates the metabolism of plants, algae and bacteria, in particular vitamin and cofactor biosynthesis.
