Prochlorococcus is a genus of very small (0.6 μm) marine cyanobacteria with an unusual pigmentation. These bacteria belong to the photosynthetic picoplankton and are probably the most abundant photosynthetic organism on Earth. Prochlorococcus microbes are among the major primary producers in the ocean, responsible for a large percentage of the photosynthetic production of oxygen. Prochlorococcus strains, called ecotypes, have physiological differences enabling them to exploit different ecological niches. Analysis of the genome sequences of Prochlorococcus strains show that 1,273 genes are common to all strains, and the average genome size is about 2,000 genes. In contrast, eukaryotic algae have over 10,000 genes.
Trichodesmium, also called sea sawdust, is a genus of filamentous cyanobacteria. They are found in nutrient poor tropical and subtropical ocean waters. Trichodesmium is a diazotroph; that is, it fixes atmospheric nitrogen into ammonium, a nutrient used by other organisms. Trichodesmium is thought to fix nitrogen on such a scale that it accounts for almost half of the nitrogen fixation in marine systems globally. Trichodesmium is the only known diazotroph able to fix nitrogen in daylight under aerobic conditions without the use of heterocysts.
Lyngbya is a genus of cyanobacteria, unicellular autotrophs that form the basis of the oceanic food chain.
Oscillatoria is a genus of filamentous cyanobacteria. It is often found in freshwater environments. Its name refers to the oscillating motion of its filaments as they slide against each other to position the colony to face a light source. Oscillatoria uses photosynthesis to survive and reproduce. Each filament of Oscillatoria consists of a row of cells called a trichome. The tip of the trichome oscillates like a pendulum.
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of Rhodophyta (red), Phaeophyta (brown) and Chlorophyta (green) macroalgae. Seaweed species such as kelps provide essential nursery habitat for fisheries and other marine species and thus protect food sources; other species, such as planktonic algae, play a vital role in capturing carbon and producing at least 50% of Earth's oxygen.
Edible seaweed, or sea vegetables, are seaweeds that can be eaten and used for culinary purposes. They typically contain high amounts of fiber. They may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. Seaweeds are also harvested or cultivated for the extraction of polysaccharides such as alginate, agar and carrageenan, gelatinous substances collectively known as hydrocolloids or phycocolloids. Hydrocolloids have attained commercial significance, especially in food production as food additives. The food industry exploits the gelling, water-retention, emulsifying and other physical properties of these hydrocolloids.
Lyngbyatoxin-a is a cyanotoxin produced by certain cyanobacteria species, most notably Moorea producens. It is produced as defense mechanism to ward off any would-be predators of the bacterium, being a potent blister agent as well as carcinogen. Low concentrations cause a common skin condition known as seaweed dermatitis.
Lyngbya majuscula is a species of filamentous cyanobacteria in the genus Lyngbya. It is named after the Dane Hans Christian Lyngbye.
The Sippewissett microbial mat is a microbial mat in the Sippewissett Salt Marsh located along the lower eastern Buzzards Bay shoreline of Cape Cod, about 5 miles north of Woods Hole and 1 mile southwest of West Falmouth, Massachusetts, in the United States. The marsh has two regions, the Great Sippewisset Marsh to the north and Little Sippewisset Marsh to the south, separated from each other by a narrow tongue of land. The marsh extends into an estuary in which the intertidal zone provides a dynamic environment that supports a diverse ecology, including threatened and endangered species such as the roseate tern. The ecology of the salt marsh is based in and supported by the microbial mats which cover the ground of the marsh.
Hectochlorin is a lipopeptide that exhibits potent antifungal activity against C. albicans and a number of plants pathogens, as well as inhibiting growth of human cell lines by hyperpolymerization of actin. It was originally isolated from the filamentous cyanobacterium Moorea producens JHB, collected from Hector Bay, Jamaica, 1996, which is a strain also known for being the producer of other two potent biomolecules named Jamaicamide A and Cryptomaldamide. Due to its activity against plants pathogens, synthetic efforts elucidated the compound’s total synthesis in 2002. Moorea species are normally the main component of the dietary of some sea hares, which concentrate the cyanobacterial metabolites as a mechanism of defense from predators. Therefore, in 2005, hectochlorin was re-isolated from the Thai sea hare Bursatella leachii, along with a new analogue, deacetylhectochlorin. Another reisolation of hectochlorin was reported in 2013, from another Moorea producens strain (RS05), isolated from the Red Sea, surprising in a non-tropical environment, as opposed to the other Moorea strains isolated before. The predicted biosynthesis of hectochlorin was published in 2007 and consists in a hybrid NRPS-PKS, with a hexanoic acid as start unit that becomes halogenated twice in the position 5, producing fairly rare gem-dichloro group, that along with two 2,3-dihydroxyisovaleric acid (DHIV) units compose a very interesting bioactive molecule.
Dragomabin is a lipopeptide isolated from the marine cyanobacteria Lyngbya majuscula. It has in vitro antimalarial activity. In 2018, a laboratory synthesis of dragomabin was reported. The synthesis identified a misassignment of the configuration of the stereogenic center on the alkyne-bearing fragment and it was revised from (S) to (R).
Antillatoxin (ATX) is a potent lipopeptide neurotoxin produced by the marine cyanobacterium Lyngbya majuscula. ATX activates voltage-gated sodium channels, which can cause cell depolarisation, NMDA-receptor overactivity, excess calcium influx and neuronal necrosis.
Debromoaplysiatoxin is a toxic agent produced by the blue-green alga Lyngbya majuscula. This alga lives in marine waters and causes seaweed dermatitis. Furthermore, it is a tumor promoter which has an anti-proliferative activity against various cancer cell lines in mice.
Trichodesmium erythraeum is a marine cyanobacteria species characterized by its prolific diazotrophic capabilities. They play a dominant role in the ocean ecosystem, supplying a steady and significant source of new, biologically available nitrogen and cycling phosphorus. By nature of its filamentous morphology, T. erythraeum is also known to congregate into large, long colonies, sizeable enough to be seen as sawdust-like particles to the naked eye and pigmented marine regions in satellite images, typically found in oligotrophic tropical and subtropical waters. These blooms are responsible for the famous coloration of the Red Sea.
Kalkitoxin, a toxin derived from the cyanobacterium Lyngbya majuscula, induces NMDA receptor mediated neuronal necrosis, blocks voltage-dependent sodium channels, and induces cellular hypoxia by inhibiting the electron transport chain (ETC) complex 1.
Valerie J. Paul is the Director of the Smithsonian Marine Station at Fort Pierce, in Fort Pierce, FL since 2002 and the Head Scientist of the Chemical Ecology Program. She is interested in marine chemical ecology, and specializes in researching the ecology and chemistry of Cyanobacteria, blue-green algae, blooms. She has been a fellow of the American Association for the Advancement of Science since 1996, and was the chairperson of the Marine Natural Products Gordon Research Conference in 2000.
Marine primary production is the chemical synthesis in the ocean of organic compounds from atmospheric or dissolved carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through chemosynthesis, which uses the oxidation or reduction of inorganic chemical compounds as its source of energy. Almost all life on Earth relies directly or indirectly on primary production. The organisms responsible for primary production are called primary producers or autotrophs.
Stylocheilus striatus is a species of sea hare found in the Indo-pacific region living from the intertidal zone to a depth of 30 metres. Common names include lined sea hare, blue ring sea hare and furry sea hare. Mature animals can reach sizes of up to 65 mm in length and are brown in colour with blue spots. Their diet mainly consists of blue algae. They play an important role in controlling toxic blooms of the cyanobacterium Lyngbya majuscula.
Jamaicamide A is a lipopeptide isolated from the cyanobacterium Moorea producens, formerly known as Lyngbya majuscula. Jamaicamide A belongs to a family of compounds collectively called jamaicamides, which are sodium channel blockers with potent neurotoxicity in a cellular model. Jamaicamide A has several unusual functionalities, including an alkynyl bromide, vinyl chloride, β-methoxy eneone system, and pyrrolinone ring.
Lyngbyastatins 1 and 3 are cytotoxic cyclic depsipeptides that possess antiproliferative activity against human cancer cell lines. These compounds, first isolated from the extract of a Lyngbya majuscula/Schizothrix calcicola assemblage and from L. majuscula Harvey ex Gomont (Oscillatoriaceae) strains, respectively, target the actin cytoskeleton of eukaryotic cells.
