Algae are also closely related to medicine and agriculture. Some of them are directly used as medicine, such as kelp, Undaria pinnatifida and Sargassum fusiforme in brown algae, which have the effect of preventing and treating goiter. The bitter gourd powder and digitalis in red algae can be used as specific drugs to drive ascaris. Alginic acid extracted from brown algae, mannitol and agar extracted from red algae are also widely used in medicine. For example, alginic acid can be used as raw materials for making dental casts and hemostatic drugs; Mannitol can eliminate brain edema and induce diuresis. Agar gel can be used as a laxative to treat constipation, and can also be used as a medicine base for making ointment, a medicine coating for powder and a coagulant for bacterial culture medium. Soil algae can not only accumulate organic matter, stimulate the activities of soil microorganisms, increase the oxygen content in soil, prevent the loss of inorganic salts and reduce soil erosion, but also some cyanobacteria can fix free nitrogen in the air, which plays an important role in improving soil fertility. In addition, algae is the basis of fish food chain, and the natural bait of fish generally comes directly or indirectly from phytoplankton, so in freshwater fish culture, algae are propagated through fertilization to provide bait for fish. However, when a large number of phytoplankton bloom, a large number of fish often die because of lack of oxygen or toxic substances in the water.
Products made from algae, especially alginate, have been widely used in industrial production. For example, agar can be used as a coagulant in food industry to make soft candy with sugar and glutinous rice paper with starch to wrap sugar. Adding agar to bread can keep bread soft for a long time, and adding sherbet can make frozen juice. Adding agar to canned fish can keep the original shape of fish and prevent it from scattering during transportation; In Japan, Europe and America, agar is also used as a clarifier for brewing wine, vinegar and soy sauce. In the construction industry, alginic acid can be used not only for painting walls, cement reinforcement, coating wood, metal products and machine tools, but also as a substitute for grid plates and linoleum. In the textile industry, there are about 30,000 species of algae, mainly distributed in fresh water or seawater. Plants are diverse in morphology, including single cells, colonies (composed of many single cells, with no close physiological relationship between cells), multicellular filaments and phyllodes. Higher algae have simple tissue differentiation. Plants (algae for short) vary greatly in size, as small as a few microns, which can only be seen under a microscope; Larger ones can be seen by naked eyes, and the maximum overall length can reach 100 meters or more.
Edit this paragraph for business purposes.
Algae have a wide range of commercial uses. Algae products include agarose (such as agar) made from more than 70 kinds of red algae. Agar is used in the manufacture of canned fish, the packaging of cooked fish, the sizing of fabrics, the manufacture of films and high-grade adhesives, and can also be used in soup, sauce, jelly, cake icing and so on. Carrageenan made from carrageenan has the same uses as agar, and also includes sodium salt, potassium salt and calcium salt. Alginate is a component of brown algae, which can be made into alkali metal salt and spun into thread like silk.
Edit the algae values in this section.
economic value
The economic importance of algae is mainly manifested in:
1. Algae fix inorganic carbon through photosynthesis and convert it into carbohydrates, thus providing a basis for water productivity. The total productivity of marine phytoplankton is estimated to be 3 1× 109 tons of carbon per year. In the transformation of the food chain, 1 kg of fish needs about 100 ~ 1000 kg of phytoplankton, so the sea areas rich in phytoplankton resources are world-famous fishing grounds, and the output of phytoplankton becomes an index to estimate marine productivity.
Secondly, in pond culture, water quality is generally judged according to the color of water, and the color of water is determined by the dominant species of algae and their reproduction degree. For example, when Rhodopseudomonas sanguinalis is the dominant species, it shows that the water quality is poor and thin; When Chlamydomonas is dominant, it is a dark green bloom with sticky blisters, indicating that the water quality is fertile; When Microcystis, Oscillatoria and Anabaena are dominant, the pool water is the floc of patina colored yarn, which is harmful to fish. The cyanobacteria formed by gymnodinium is one of the typical water quality of high-yield fish ponds such as silver carp, bighead carp, carp, crucian carp and non-crucian carp, but excessive reproduction will also worsen the water quality and cause fish flooding. In addition, unicellular algae such as Platymonas. Dunaliella salina. And Chlorella. Protein is an important natural bait for shellfish, shrimp and sea cucumber culture because of its high content.
3. Nitrogen-fixing cyanobacteria are important organisms that provide bound nitrogen on the earth, and they are also important biological nitrogen resources that can be utilized. At present, there are more than 20 species of nitrogen-fixing cyanobacteria 120, and the nitrogen-fixing capacity per hectare of rice field is 16 ~ 89 kg.
4. Kelp and Undaria pinnatifida in Phaeophyta, Porphyra in Rhodophyta, Nostoc flagelliforme in Cyanophyta, Ulva and Enteromorpha in Chlorophyta are all important edible algae.
Five, the use of seaweed in industry is mainly to provide all kinds of alginate. Kelp, kelp, Undaria pinnatifida, antlers and Sargassum fusiforme can be used as raw materials for extracting iodine, mannitol and alginate. Macroalgae, brown algae and other algae can also be used as raw materials for extracting alginate. Alginate is widely used in food, paper, chemical and textile industries. Agar can be extracted from Gracilaria, Gracilaria, ceramide, etc. It can be used as a raw material for medicine and chemical industry, and also as a culture medium for microbiology research. Carrageenan is widely used in food industry and can be extracted from algae such as Chaetoceros, Eucheuma, Taxodium, Ginkgo, Cladosporium, Scolopendra, Serpentine and Sweet Potato.
Research value
The study of marine or freshwater algae is called phycology or phycology.
The American algae collection program is famous for its inventory of 300,000 specimens.
Edit this piece of algae (alga)
Algae plants generally have pigments for photosynthesis, which can use light energy to synthesize inorganic substances into organic substances; For their own needs, it is an autotrophic plant that can live independently. Algae plants have different shapes, as small as a few microns, which can only be seen under a microscope; Larger celestial bodies are visible to the naked eye; The largest body length can reach more than 60 meters, and the structure of algae is also very complex, and it differentiates into various tissues, such as the giant cyst algae growing in the Pacific Ocean. Although there are big, small, simple and complex algae, they are basically protophytes without root, stem and leaf differentiation. Most reproductive organs are unicellular. Although the reproductive organs of some higher algae are multicellular, every cell in the reproductive organs is directly involved in reproduction. Form robes or gametes without sterile cell layers around them. The zygote of algae plants will not develop into multicellular embryos. A few lower algae are heterotrophic or temporarily heterotrophic, and can be separated from heterotrophic bacteria and fungi according to their cell structure and stored nutrients.
Algae are almost ubiquitous in nature, mainly distributed in water (fresh water or seawater). But they are also distributed in wet rocks, walls and trunks, soil, nutrient surfaces and lower layers. Algae living in water, some floating in water, some fixed on rocks in water or attached to other plants. Algae plants have low requirements on environmental conditions and strong adaptability to the environment, and can grow in an environment with poor nutrition and weak light. They are one of the first residents and pioneer plants in the new living area on the fresh inorganic substances formed after earthquakes, volcanic eruptions and floods. Some algae can live at the bottom of the sea at a depth of 100 meters, some algae can live at the north and south poles of MINUS tens of degrees or on mountains covered with snow all year round, some cyanobacteria can live in hot springs as high as 85℃, and some algae can grow with fungi to form * * *.
Used to modify cloth, pulp silk, etc. For example, Xiangyun yarn made in Guangdong, China is made of sponge rubber. Diatoms are also widely used in industry, such as nitroglycerin, which is explosion-proof and can be used as raw materials for making refractory bricks, filters and tooth powder.
With the deepening of the understanding of algae, its utilization range is also expanding. From the current preliminary research results, it can be expected that algae will play an important role in solving the problems of food shortage, energy crisis and environmental pollution that human beings generally face.