Naming of any commercially available product is not an endorsement of that product.
- Kelps (Kombu) vegetables in Japan and China
- Porphyra (nori) north Pacific. Cultivated for centuries in Japan, Korea and China. Value $1 billion per year.
- Porphyra toasted and used to wrap sushi
- Ulva eaten as a green vegetable
- Alginates – fruit drinks, salad dressing, ice creams, sherbets, cheeses, textile, cosmetic, pharmaceutical, paper and welding industry products. Some liquid fertilizers
- Chlorella – only microscopic green used commercially
- Spirulina – Christopher Hills (UK) – dried alga for chicken feed with high protein and high carotene. Imperial Valley
- California and Kona coast of Hawaii using ponds in saline soil
- Chlamydomonas and other soil algae make mucilage that loosen compacted soil. Used on compacted ash of Mt. St. Helens to restore farming.
- Calcareous algae
- Packaged Anaebaena-Azolla.
- Diatomaceous earth – used as flea killers, embalming compounds, enamel polishes.
- Diatomaceous bricks
- Diatomite used to filter sewage in UK from 1976,
- Diatomite to filter sugar cane liquors from 1914;
- Diatomite to stabilized nitroglycerine, Picture of Nobel
- Packaged Qundai-cai – China; wakame – Japan
- Phycocolloids – look for examples of commercial products mentioned or implied in the following text.
- Alginates for sizing and polishing of paper. In paint they keep pigments suspended over a range of temperatures, adhesives in manufacture of charcoal briquettes; suspending agents in food, cosmetics and medicine. Stop ice crystal formation in ice cream; clarifiers and foam stabilizers in beer. Filler in candy bars; emulsifiers in salad dressings.
- Metal alginates – cellophane like materials; canning of fruits; manufacture of artificial “foods” such as fake cherries, imitation caviar and reconstituted onion rings
- Alginates as plastics (heavy metal salts); gels as dental impressions; fibers to make high quality audio speakers
- Carrageenans used for centuries in jellies and milk puddings (blancmanges). Gelling, thickening and suspending properties are thermally reversible, or reversing states when solution is heated to a liquid and then cooled back to a gel. Very effective when is solution with proteinaceaous materials. When added to hot milk, and cooled, bonds form between carrageenan and casein to give a creamy thick texture. This led to carrageenan replacing alginates for chocolate milk, yogurts, eggnog mixes and ice creams. Its high melting point makes it useful for making desserts in hot climates. It is immune to degradation by common enzymes (unlike cellulose gum). It is used as a binder in toothpaste and also makes teeth shiny. Sizing agent in textile and leather industries. Used in aqueous solution to suspend oil-based inks to allow them to be combed or swirled to create marbleized designs on paper and fabric.
- Algae in medicine. In the west mostly the phycocolloids as binders and emulsifiers in pharmacy and in wound dressings (alginate wools are absorbent). In the orient, widely used – parasites(Digenia used as a vermifuge: learned from watching dugongs eat this alga which is now known to contain kainic acid, a potent vermifuge, coughs, gout, goiter (Laminaria), veneral disease, even tumours…. Dried, sterile Laminaria stipes used to take up fluids, increase original circumference 3-5 times, and produce non-instrument mechanical dilation of the cervical canal during birth or gynecological treatment.
- Anti-cancer – Sargassum sp., Codium pugniformis and Laminaria japonica extracts, Spirulina extracts inhibit growth of oral cancer cells. Phycocyanins have antitumour and boost immune system. Maybe a B-carotene effect Sterols reduce cholesterol. Spirulina, Chlorella and Scenedesmus lower cholesterol. Laminaria japonica administered for hypertension – effect may be related to iodine.
- Spirulina is appetite suppressant. High in B vitamins . >50g per day gives nausea unless tolerance acquired.
- Laminaria digitata and Dilsea edulis (red) have anticoagulant effects – claimed for carrageenans.
What are mucilages, gums, polymers?
Chemistry of the polymers? compositions? formulae of monomers?
Varying proportions of 3,6-anhydro-L-galactose and D- galactopyranose. Stiff gels in smaller concentrations (1- 2%) than carrageenan. Strong ability to reverse states when heated and cooled. Agarose is the neutral galactose fraction. (chromatography and electrophoresis). Hydrophilic properties make it a good moistening additive for bread. Binds to proteins and used to clarify wines, juices and vinegars – aggregated gel can be removed by filtration. Binder for medicinal tablets and capsules. Bulk laxative
D-mannuronic acid and L-galacturonic acid. also gluronic acid. Alginates first discovered by E.C.C. Stafford. They are cell wall components like pectins. Helps provide flexibility and tensile strength. Can absorb up to 200-300 times their own weight of water and this provides the flexibility. Metal salts are poorly water soluble and form gels. Pseudoplastic – i.e. make solutions less thick as more shear is applied – ideal for paint manufacture – minimize brush drag and help brush marks to disappear. After application, paint recovers its viscosity and sagging and runoff are prevented. Heavy metal salts are insoluble. Can be molded when wet and set to hard plastics. Early cloths dissolved in soapy water. Now some hope that they can make an artificial silk.
D- and L-galactose, 3,6-anhydro-D-galactose, and sulphate esters (more information in paper by Lembi and Waaland)
Are there any ill-effects?
Anti-grazing: Many anti-grazing compounds. Although few algae are established as parasites or pathogens…(the rationale goes, “they make their own food so why bother!”), there are many red algal parasites on other red algae. Only Chlorella and Prototheca (non-photosynthetic) alleged to infect people or animals. Most toxic seaweeds in tropics. Not a big problem in USA and Europe except for Hizikia which accumulates arsenic and Caulerpa which is collected for salad in the Pacific. Noxious compounds are exploited as pesticides.
Blooms can kill people, can kill fish (toxin or oxygen depletion), can be sequestered and then kill. Commonest fish kills from Prymnesium parvum which alters gill membranes oxygen permeability and is not required in large amounts. Red tides first reported from Virgin Islands in 1530. 500 documented deaths from dinoflagellates. Watch out for luminescent tides. Paralytic shellfish poisoning. A dozen different poisons which block Na movement in nerves. Associated with blooms of Protogonyaulaux sp. (Gonyaulaux). Neurotoxic shellfish poisoning from red tides in Florida (Alexandrium brevis) is caused by a lipid soluble poison with a different mechanism, but no recorded fatalities. Gambierdiscus toxicus is bottom dweller causing ciguatera poisoning. Concentrated in organs of coral eating fish.
dermatitis caused by Oscillatoria nigroviridis. Anaebaena, Lyngbya majuscula(which contains an alkaloid and a phenol which also cause experimental tumours), and Schizothrix calcicola are fresh water causes of contact dermatitis.
Some red algae may cause breathing distress. Silicosis from inhaling diatoms (not too smart to use on house pests).
Slime on hulls is the most economically significant good or damaging effect of algae. A 1mm thick layer causes 15% loss of ship speed and 80% increase in friction over a clean hull. Ecological succession begins as soon as the vessel hits the water! Usually Enteromorpha and Ectocarpus (brown), which are both tolerant to high fluctuation of salinity and temperature. Costs of friction and increased biomass in 1976 was 1.3 billion. US Navy could save $150 million in fuel per year. Problem is 2500 years old! People have tried impregnating hulls with grease, tar, toxics (As or S mixed with oil); charring the surface, and applying copper or lead sheets. Now there is mechanical removal. electrochemical chlorination, and use of anti-fouling paints (Cu added). Now there are Cu tolerant algae!
Weeds! Often stimulated by high P levels. Mats clog drains, Legionella gets into air-conditioning along with blue-green algae. Can take over aquaculture systems. Spirogyra, Hydrodictyon and Pithophora form mats that waterfront property owners and swimmers don’t like. Epiphytes can kill sea grasses cutting off light.
Can natural product be enhanced?
What pests are there?
Chytrids and rots for Porphyra cultivation. Red algae parasites of other red algae.
Are their any predictable future uses?
(See Algae and Human Affairs by Lembi and Waaland)
- Chelating agents for radioactives and heavy metal poisoning. Detoxify heavy metals
- Potential for medicines: Many antibiotics (bromophenols; fatty acids, tannins and terpenes).
- Red algal polysaccharides may control cold-sore Herpes. They are the active compound in Zovirax – by interfering with virus binding to human cell membranes.
- Sulphur-containing lipids from blue-greens Lyngbya lagerheimii and Phormidium tenue may protect human cells against cytopathic effects of HIV.
- Alginic acid (Nomozan) may inoculate some crops against viruses.
- Research tools: kainic acid breaks down dendrites at higher doses producing symptoms similar to patients with Huntington’s Syndrome. Phycobiliproteins can fluoresce and have uses in diagnostics to track antibodies.
- Pesticides: Someone noticed that flies landing on dried fronds of Chondria died.
- Anti-algals: Possibly from corals!
- Aquaculture: for protein and primary producers to feed the animal crop. Phytoplankton at base of food chain. Can we combine domestic waste treatment with aquaculture and algae?
- Source of paper: Bioindicators of pollution:
- Microbial mining:
- Space travel: air cleaners and recycle human waste, even food source
Who is in the industry? What are economics?
Extension of nori season by spore refrigeration + production increase from 8 people making 1500 sheets per day to machines that to that work in an hours
Spirulina – Christopher Hills (UK) – dried alga for chicken feed with high protein and high carotene. Imperial Valley California and Kona coast of Hawaii using ponds in saline soil.
Alginic acid industry started in Japan in 1923. Most still harvested from wild. China has cultivation of Laminaria for phycocolloids
Euchema cultivation improvements since 1971 has seen production from 500 metric tons carrageenan/year to 25,000 metric tons/year.
Diatomaceous earth – used as flea killers, embalming compounds, enamel polishes.
Diatomaceous bricks – Emperor Justinian order the dome of the church of Hagia Sophia in Istanbul in AD 532.
Diatomite used to filter sewage in UK from 1976, to filter sugar cane liquors from 1914; Nobel stabilized nitroglycerine, USA produces 38%; also Russia, France and Denmark. Mined (open or underground. Dried from 60 to 5% water, ground and sorted. 68% of product used in filter aids, especially water purification.
Wastewater. Details of waste treatment . Tertiary treatment can use algal – bacterial culture + light + sewage leads to bio-oxidation. Produces precipitated organic material (sludge) plus oxygen which maintains aerobic bacteria. Organisms absorb N and P from sewage for their own use. With photosynthetic oxidation BOD drops 90% and P drops 80% . Get some examples (check Iona, but Simpson quotes Hollister, CA.