Technology for producing protein mass from algal cells
Feed proteins from algae. In Russia and a number of other countries, single-cell alga Chlorella and Scenedesmus, as well as blue-green algae from the genus Spirulina, are used to produce fodder protein, which are capable of synthesizing proteins and other organic substances from carbon dioxide, water and minerals by absorbing the energy of sunlight. For their cultivation it is necessary to provide certain modes of lighting and temperature, and also large volumes of water are required. Most often in natural conditions, algae are grown in southern regions using open-type swimming pools, but technologies for their cultivation in a closed system are also being developed.
Algae chlorella and spedesdemus require a neutral environment for their cultivation, their cells have a fairly dense cellulose membrane, which makes them worse digested in the animals. For better digestion, cellulose shells are destroyed by special treatment.
Spirulina cells are 100 times larger than chlorella, but they do not have a strong cellulose membrane and therefore are better digested in the animals. Spirulina is grown in alkaline medium (pH 10-11), under natural conditions in alkaline lakes. By the intensity of accumulation of biomass, algae, although inferior to fodder yeast and bacteria, significantly exceed agricultural plants. When grown in cultivators of open type with 1 hectare of water surface, up to 70 tons of dry biomass can be produced per year, while for wheat growing 3-4 tons, rice 5 tons, soybean 6 tons, maize 7 tons.
The technology for obtaining protein mass from algal cells includes the cultivation of industrial crops in cultivators of open or closed type, the separation of algae from the mass of water, the preparation of a commercial product in the form of a suspension, dry powder or paste-like mass. The process of separating algal cells from the mass of water is energy intensive, since it is necessary to process large volumes of liquid.
In Russia, the most common cultivation of chlorella, which is used to feed farm animals in the form of a suspension (1.5 g / l dry matter) or dry powder. The daily norm of the chlorella suspension when feeding young cattle is 3-6 l, adult animals - 8-10 l. When ruminant animals are added to the feed of chlorella flour, 50% of the vegetable protein can be replaced with protein from the algae.
Of great importance is the growth of algae on the drainage of industrial enterprises, thermal power plants, livestock complexes, since in these cases, along with the production of fodder protein, the problems associated with environmental protection are simultaneously being addressed. So, for example, the cultivation of a scene of spesdemus or chlorella on the drainage of livestock complexes for 15 days makes it possible to almost completely clear them of organic substances, the smell and color disappear. When algae are cultivated, industrial waste water or effluent from thermal power plants uses excess heat from these facilities, and carbon dioxide is utilized, formed as a by-product of technological processes and as a result of incineration of various wastes.
Cultivators for growing open algae are available in many countries. The largest chlorella company, Chlorella San Company, is in Japan. In Bulgaria, the waters of the thermal springs are cultivated with chlorella algae and spetesdemus, with Bulgarian scientists able to produce chlorella strains without a cellulose shell, so that the biomass of such cells is well digested in the animals. A significant amount of protein concentrates from alga spirulina are produced in the countries of central Africa and Mexico, where there are alkaline lakes. The largest producer of various products from biomass and spirulina proteins is the firm Coca Texcoco (Mexico). In Italy, technology is developed for the cultivation of spirulina cells on sea water and in cultivators of closed type.
Due to the fact that the biomass of algae of the genus Spirulina is easily digested by gastric juice enzymes and is characterized by a high protein content (up to 70% of dry weight), well balanced in amino acid composition, it is used in several countries for cooking foods, mainly confectionery products enriched protein.
Taking into account the importance of introduced into the industrial culture of algae as an additional source of high-grade protein for feeding agricultural animals and human nutrition, scientists of different directions - breeders, geneticists, biochemists - are conducting research on improving existing industrial strains of unicellular algae and obtaining new genotypes that should combine high intensity of photosynthesis, cold resistance, good digestibility, ability to synthesize a large number of b LCA better quality (higher content of essential amino acids), and dispose of the substrate fully. An important role in the implementation of such studies is given to methods of genetic engineering.
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