Limu Kohu | |
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Asparagopsis taxiformis in Mayotte. | |
Scientific classification | |
Clade: | Archaeplastida |
Division: | Rhodophyta |
Class: | Florideophyceae |
Order: | Bonnemaisoniales |
Family: | Bonnemaisoniaceae |
Genus: | Asparagopsis |
Species: | A. taxiformis |
Binomial name | |
Asparagopsis taxiformis | |
Synonyms | |
Asparagopsis sanfordiana |
Asparagopsis taxiformis (red sea plume or limu kohu), formerly A. sanfordiana, [1] is a species of red algae, with cosmopolitan distribution in tropical to warm temperate waters. [2] Researchers have demonstrated that feeding ruminants a diet containing 0.2% A. taxiformis seaweed reduced their methane emissions by nearly 99 percent. [3]
Like many red algae, A. taxiformis has a haplodiplophasic lifecycle, with each phase morphologically distinct. The species' diploid stage was initially described as Falkenbergiahillebrandii(Bornet) Falkenberg 1901 because it was thought to be a separate species.
Asparagopsis is one of the most popular types of limu. [4] in the cuisine of Hawaii, it is principally a condiment. [5] It is known as Limu kohu in the Hawaiian language, meaning "pleasing seaweed". [6] Limu kohu has a bitter taste, somewhat reminiscent of iodine, [7] and is a traditional ingredient in poke.
The essential oil of limu kohu is 80% bromoform (tri-bromo-methane) by weight. [8] It also includes many other bromine- and iodine-containing organic compounds. [5]
In 2014, researchers at CSIRO and James Cook University (supported by Meat & Livestock Australia) demonstrated that treating ruminal fluid with one to two percent red seaweed reduced their methane emissions by over 90 percent. [9] Of 30 types of seaweed tested, A. taxiformis showed the most promise, with nearly 99 percent effectiveness. [10]
The findings spurred further investigation into its effects on ruminant animal enteric methane production. In 2016, the same team showed that 2-5% of seaweed biomass effectively reduced production by 98-100% [11] in vitro and, in a separate study, identified the bioactives in A. taxiformis. While dichloromethane extract was the most potent bioactive, reducing methane production by 79%, bromoform and dibromochloromethane had the highest activity inhibiting methane production, and only bromoform is present in sufficient quantities to be effective. [12] In 2020, they showed that a 0.2% addition of A. taxiformis to cattle’s feed reduced the livestock’s methane emissions by over 98%. [13] In 2021, a team from UC Davis found that additions of 0.25% and 0.5% reduced cattle’s enteric methane emissions by 69.8% and 80% respectively. [14]
Supply from wild harvest is not expected to be adequate to support broad adoption. Subsequent to the Australian study, CSIRO established FutureFeed Pty Ltd., which holds the global intellectual property (IP) rights for the use of Asparagopsis for livestock feed, with the aim of significantly reducing enteric methane emissions in ruminants. [15] In 2020, FutureFeed won a Food Planet Prize worth USD $1 million for the research behind its inception. [16]
A. taxiformis has yet to be commercially farmed at scale, but several companies are working towards it as they make the seaweed available to the livestock industry. A research/development initiative called Greener Grazing is seeking to close the life cycle of A. taxiformis and demonstrate ocean-based grow-out. [17]
A startup out of KTH Royal Institute of Technology, Volta Greentech, Sea Forest, SeaStock, Immersion Group, Synergraze, Symbrosia and Blue Ocean Barns, are growing A. taxiformis in vertical, near-shore land-based tanks, using seawater to provide the proper temperature and nutrients. [18] [19] Symbrosia, from Yale University, is looking to integrate the cultivation with whiteleg shrimp on land, using a patent-pending technology. [20] Another start-up, CH4 Global, has developed energy-efficient EcoParks in Australia and New Zealand to produce A. taxiformis for use in its solutions for feedlot cattle. [21] CH4 Global has partnered with Clean Seas to grow A. taxiformis at Arno Bay, Australia, where it uses carbon and nitrogen waste from Clean Seas’ ocean-based fish farms as food for the seaweed. [22] In 2023 CH4 global reported its first commercial sale and intentions to feed the additive to 10,000 cattle. [23]
Volta Greentech, Blue Ocean Barns, Symbrosia and CH4 Global have been backed by venture capital funds.
Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.
Fodder, also called provender, is any agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food given to the animals, rather than that which they forage for themselves. Fodder includes hay, straw, silage, compressed and pelleted feeds, oils and mixed rations, and sprouted grains and legumes. Most animal feed is from plants, but some manufacturers add ingredients to processed feeds that are of animal origin.
Burping is the release of gas from the upper digestive tract of animals through the mouth. It is usually audible.
Bromoform is an organic compound with the chemical formula CHBr3. It is a colorless liquid at room temperature, with a high refractive index and a very high density. Its sweet odor is similar to that of chloroform. It is one of the four haloforms, the others being fluoroform, chloroform, and iodoform. It is a brominated organic solvent. Currently its main use is as a laboratory reagent. It is very slightly soluble in water and is miscible with alcohol, benzene, chloroform, ether, petroleum ether, acetone and oils.
Enteric fermentation is a digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. FAO estimated that ruminant livestock contribute to around 34.5 percent of the total anthropogenic methane emissions.
Dibromochloromethane is a colorless to yellow, heavy and nonflammable compound with formula CHBr
2Cl. It is a trihalomethane. The substance has a sweet odour. Small quantities of dibromochloromethane are produced in ocean by algae.
Mastocarpus stellatus, commonly known as carrageenan moss or false Irish moss, is a species in the Rhodophyceae division, a red algae seaweed division, and the Phyllophoracea family. M. stellatus is closely related to Irish Moss. It grows in the intertidal zone. It is most collected in North Atlantic regions such as Ireland and Scotland, together with Irish moss, dried, and sold for cooking and as the basis for a drink reputed to ward off colds and flu. Marine biologists have completed studies on the medicinal reputation of M. stellatus to discover the full potential of its pharmaceutical benefits. Additionally, marine biologists have conducted research on its potential to serve as an alternative to plastic. The application of M. stellatus in these different industries is correlated with the seaweed's adaptations which developed in response to the environmental stressors present around its location on the rocky intertidal.
Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it is difficult because it is a gas at standard temperature and pressure. In the Earth's atmosphere methane is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. Methane is an organic compound, and among the simplest of organic compounds. Methane is also a hydrocarbon.
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.
Organobromine chemistry is the study of the synthesis and properties of organobromine compounds, also called organobromides, which are organic compounds that contain carbon bonded to bromine. The most pervasive is the naturally produced bromomethane.
Asparagopsis armata is a species of marine red algae, in the family Bonnemaisoniaceae. English name(s) include red harpoon weed. They are multicellular eukaryotic organisms. This species was first described in 1855 by Harvey, an Irish botanist who found the algae on the Western Australian coast. A. armata usually develops on infralittoral rocky bottoms around the seawater surface to around 40m of depth. Marine algae like A. armata are considered "autogenic ecosystem engineers" as they are at the very bottom of the food chain and control resource availability to other organisms in the ecosystem.
Red algae, or Rhodophyta, make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 recognized species within over 900 genera amidst ongoing taxonomic revisions. The majority of species (6,793) are Florideophyceae, and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, no terrestrial species exist, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity.
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.
Asparagopsis is a genus of edible red macroalgae (Rhodophyta). The species Asparagopsis taxiformis is found throughout the tropical and subtropical regions, while Asparagopsis armata is found in warm temperate regions. Both species are highly invasive, and have colonised the Mediterranean Sea. A third accepted species is A. svedelii, while others are of uncertain status.
3-Nitrooxypropanol (abbreviated as 3-NOP or 3NOP) is a synthetic organic compound with the formula HOCH2CH2CH2ONO2. It is the mononitrate ester of 1,3-propanediol and acts as an enzyme inhibitor that specifically targets methyl coenzyme M reductase (MCR), the enzyme that catalyzes the final step of methanogenesis in microbes living the digestive system of ruminants, such as cows and sheep.
Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
FutureFeed is a ruminant livestock feed ingredient based on seaweed that can reduce methane emissions, established by Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). FutureFeed holds the global intellectual property to use the seaweed Asparagopsis for livestock feed. Lowered methane emissions can be achieved by the addition of a small amount of the seaweed into the daily diet of livestock. This discovery was made by a team of scientists from CSIRO and James Cook University (JCU), supported by Meat & Livestock Australia (MLA), who came together in 2013 to investigate the methane reduction potential of various native Australian seaweeds.
The amount of greenhouse gas emissions from agriculture is significant: The agriculture, forestry and land use sectors contribute between 13% and 21% of global greenhouse gas emissions. Emissions come from direct greenhouse gas emissions. And from indirect emissions. With regards to direct emissions, nitrous oxide and methane makeup over half of total greenhouse gas emissions from agriculture. Indirect emissions on the other hand come from the conversion of non-agricultural land such as forests into agricultural land. Furthermore, there is also fossil fuel consumption for transport and fertilizer production. For example, the manufacture and use of nitrogen fertilizer contributes around 5% of all global greenhouse gas emissions. Livestock farming is a major source of greenhouse gas emissions. At the same time, livestock farming is affected by climate change.
Jennifer E. Smith is an American marine ecologist and coral reef expert who works at the Scripps Institution of Oceanography. Her research investigates how physical and biological processes impact the function of marine communities.