Husain Al rubiee Most algal groups are considered photoautotrophs that is depending entirely upon their photosynthetic apparatus for their metabolic necessities using sunlight as the source of energy and CO ID: 1026797
Download Presentation The PPT/PDF document "ALGAL NUTRITION Dr . Ghaidaa" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. ALGAL NUTRITIONDr . Ghaidaa Husain Al-rubiee
2. Most algal groups are considered photoautotrophs, that is, depending entirely upon their photosynthetic apparatus for their metabolic necessities, using sunlight as the source of energy, and CO2 as the carbon source to produce carbohydrates and ATP. ALGAL NUTRITION
3. Photo autotrophic and synthesis their own food from carbon dioxide and water.Aquatic forms obtain CO2 and water by diffusion and osmosis Aerials obtain water from damp substratum and CO2 from air They also synthesis oil and proteins from carbohydrates
4. Most algal divisions contain colorless Heterotropic species that can obtain organic carbon from the external environment either by taking up dissolved substances (Osmotrophy) or by engulfing bacteria and other cells as particulate prey (phagotrophy). Algae that cannot synthesize essential components such as the vitamins of the B12 complex or fatty acids also exist, and have to import them; these algae are defined auxotrophic
5. Algae Mode of Nutrition
6. However, it is widely accepted that algae use a complex spectrum of nutritional strategies, combining photoautotrophy and heterotrophy, which is referred to as Mixotrophy.
7. Growth modes of algae (microalgae)
8. Some mixotrophs are mainly photosynthetic and only occasionally use an organic energy source. Other mixotrophs meet most of their nutritional demand by phagotrophy.
9. Photosynthetic fixation of carbon and use of particulate food as a source of major nutrients (nitrogen, phosphorus, and iron) and growth factors (e.g., vitamins, essential amino acids, and essential fatty acids) can enhance growth, especially in extreme environments where resources are limited. Heterotrophy is important for the acquisition of carbon when light is limiting and, conversely, autotrophy maintains a cell during periods when particulate food is rare .
10. ● Obligate heterotrophic algae. They are primarily heterotrophic, but are capable of nutritious themselves by phototrophy when prey concentrations limit heterotrophic growth (e.g., Gymnodium sp).On the basis of their nutritional strategies, algae are into classified four groupsGymnodium sp
11. ● Obligate phototrophic algae. Their primary mode of nutrition is phototrophy , but they can supplement growth by phagotrophy and/or osmotrophy when light is limiting (e.g., Dinobryon sp,).● Facultative mixotrophic algae. They can grow equally well as phototrophs and as heterotrophs (e.g., Fragilidium sp ).
12. ● Obligate mixotrophic algae. Their primary mode of nutrition is phototrophy, but phagotrophy and/or osmotrophy provides substances essential for growth (photoautotrophic algae can be included in this group) (e.g., Euglena sp).
13. DIM, dissolved inorganic material , DOM, dissolved organic material.
14. Nutrient storage As in land plants, the major carbohydrate storage product of the chlorophyceae is usually starch in the form of amylose or amylopectin. These starches are polysaccharides in which the monomer, or fundamental unit, is glucose. The Cryptophyceae also store amylose and amylopectin. These starches are stored outside the chloroplast but within the surrounding membranes of the chloroplast endoplasmic recticulum. Most Dinophyceae store starch outside the chloroplast, often as a cap over a bulging pyrenoid. The major carbohydrate storage product of Rhodophyceae (red algae) is a type of starch molecule (Floridean starch) that is more highly branched than amylopectin. Floridean starch is stored as grains outside the chloroplast.
15. The major carbohydrate storage product of the Chromophyte algae and Euglenophyceae is formed from glucose molecules. These polysaccharide compounds are always stored outside the chloroplast. In the chromophyte algae, the molecules are usually small (16–40 units of sugar) and are stored in solution in vacuoles, whereas in the euglenophyte algae, the molecules of paramylon are large (approximately 150 units of sugar) and are stored as grains.In cyanophyceae the reserve foods are cyanophycean starch and cyanophycean granules (protein). The number of glucose units in each storage product varies among the algal classes, and each type is given a special name—i.e., chrysolaminarin in diatoms and yellow -green algae , laminarin in brown algae , leucosin in chrysophytes, and paramylon in euglenophytes.
16.