Saran's Learn Microbiology

  NUTRITION OF ALGAE ·      Majority of the Algae are Photoautotrophic in nature. They synthesize their food from inorganic materials such as carbon dioxide, water and minerals by means of Photosynthesis. ·        The mode of nutrition in Algae is primarily of three types, namely a)      Photoautotrophic algae - Undergo Photosynthesis to synthesize their food. b)      Heterotrophic algae - Utilize Organic nitrogen or carbon sources and nutrients in soil or water to synthesize essential oils, fats and proteins . c)      Mixotrophic algae - Utilize both Organic and Inorganic sources to fulfil their growth and nutritional needs. ·        On the basis of their nutritional strategies, Algae are into classified four groups: a)      Obligate Phototrophic Algae ü   Obtain nutrition by utilizing Inorganic sources like CO 2 , H 2 O and Sunlight or through Photosynthesis. ü   In case of limited Sunlight, Obligate Phototrophic Algae sustain life through Phagotrophy (engulfment

  CLASSIFICATION OF ALGAE Characters Division of Algae Chlorophyta (Green algae) Rhodophyta      (Red algae) Phaeophyta (Brown algae) Chrysophyta  ( Golden algae, Yellow-green algae and Bacillariophyceae - Diatoms ) Pyrrophyta (Dinoflagellates) Euglenophyta (Euglenids) Kingdom Plantae Rhodophyta Stramenophila Stramenophila Alveolatta Euglenozoa Representative genera Chlamydomonas Spirogyra Chara Prototheca Codium Trebouxia Chondrus Gracilaria Gelidium Antithamnion Macrocystis Stephanodiscus Gymnodinium Gonyaulax Pfiesteria Euglena Cellular nature Unicellular or Multicellular Multicellular Multicellular Unicellular Unicellular Unicellular Habitat Fresh, Brackish, and Salt wat

ULTRASTRUCTURE OF ALGAE Cell wall ·        The Algal cell is bounded by a thin, cellulose cell wall. ·       Cellulose is the major component of the Algal cell wall but in some cases some other components like Glycoprotein or Agar or Calcium carbonate or Alginic acid also present in Algal cell wall along with Cellulose. ·        Cellulose layer is finely striated with parallel Cellulose fibrils. ·       In many species of Algae, there is a Pectose layer external to it which dissolves in water and forms a mucilaginous Pectin layer. ·        Cell wall is absent in the Algae belonging to the Phylum Euglenophyta. Plasmalemma ·     Plasmalemma is present just below the Cell wall and consists of two opaque layers which remain separated by less opaque zone. Protoplast ·        Protoplast is bounded by Plasmalemma. ·    Protoplast is differentiated into Cytoplasm, Nucleus, Chloroplast with one or more Pyrenoids, Mitochon