Chapter 10 - Taxonomy of Other Microbes PDF

Taxonomy of Other Microbes By: Espiritu, Rico Jay Ibajan, Toni Babe BS Biology- 4 Microbiology Topic outline Protoza: Protozoan Classification Protozoan Structure Protozoan Growth and Development Algal Classification Fungal Classification  PROTOZOANS Protozoa are unice...

Taxonomy of Other Microbes By: Espiritu, Rico Jay Ibajan, Toni Babe BS Biology- 4 Microbiology Topic outline Protoza: Protozoan Classification Protozoan Structure Protozoan Growth and Development Algal Classification Fungal Classification  PROTOZOANS Protozoa are unicellular, eukaryotic, heterotrophic organisms. They are either free-living or parasites. There are around 65000 species of protozoans categorised in different groups. They lack a cell wall.  General Characteristics of Protozoa Habitat- Protozoa are found in the aquatic environment. They live in freshwater or oceans. Some are free-living and some are parasitic in plants and animals. Mostly they are aerobic but some are anaerobic and present in the rumen or human intestine. Size and Shape- The size and shape of Protozoa vary greatly, from microbial (1µm) to large enough and can be seen by the naked eye. In some of the protozoans especially in ciliates, the cell is supported by Pellicle, which may be flexible or rigid and give organisms the definite shape and help in locomotion. Cellular Structure They are unicellular having a eukaryotic cell. The metabolic functions are performed by some specialised internal structures.  Life Cycle Stages The stages of parasitic protozoa that actively feed and multiply are frequently called trophozoites; in some protozoa, other terms are used for these stages. Cysts are stages with a protective membrane or thickened wall. Protozoan cysts that must survive outside the host usually have more resistant walls than cysts that form in tissues. Reproduction Binary fission, multiple asexual division occurs in some forms. Both sexual and asexual reproduction occur in the Apicomplexa. Nutrition All parasitic protozoa require preformed organic substances—that is, nutrition is holozoic as in higher animals.  PROTOZOAN CLASSIFICATIONS 1. Mastigophora or Flagellated protozoans: 2. Sarcodina or Amoeboids: Trypanosoma  PROTOZOAN CLASSIFICATIONS 3. Sporozoa or Sporozoans: 4. Ciliophora or Ciliated protozoans: Paramecium  Algae "Alga is a term that describes a diverse group of eukaryotic, photosynthetic lifeforms. These organisms do not share a common amcesyor and hence, are not related to each other (polyphyletic)."  Characteristics of Algae Algal cells are eukaryotic. The algal cell walls consist of mannans, cellulose and Galatians. They are photosynthetic. Algae can be either unicellular or multicellular. They lack well-defined body. Algaes are found where there is adequate moisture. Sexual and asexual forms of reproduction. Free-living Classifications of Algae One of the best known algal classification was proposed by Fritsch, who divided them into eleven classes (1945) in his book titled "The Structure and Reproduction of Algae". Chlorophyceae Chloromonodineae Xanthophyceae Euglinineae Chrysophyceae Phaeophyceae Bacillariophyceae Rhodophyceae Cryptophyceae Myxophycaea (Cyanophyceae) Dinophyceae Class Chlorophyceae (Green Algae) Habitat: Most are aquatic, but some can live on surface of snow, on tree trunks, in soils, or symbiotically with protozoans, hydras or lichen-forming fungi. Pigments: Chlorophylls a and b, carotenoids Structure: Unicellular motile to heterotrichous filaments. Cellulose cell walls. Reproduction: sexual reproduction ranges from isogamous to advanced oogamous type. Reserve food: starch 1. Structure of green algae (Louise and Richard, 2004). | Download... Example: Halimeda spp., Chlamydomonas Class Xanthophyceae (Yellow-green Algae) Habitat: Most live in freshwater, some are marine. Pigments: Yellow xanthophyll Structure: Unicellular motile to simple filamentous. Pectic compound-rich cell walls, motile cells have unequal flagella, pyrenoids are absent. Reproduction: sexual reproduction is rare and always isogamous. Example: Vaucheria Class Chrysophyceae (Golden algae) Habitat: Abundant in freshwater and marine environments. Some in cold freshwater. Pigments: Contain chlorophylls a and c, which are masked by the accessory pigment fucoxanthin, a carotenoid. Structure: Motile cells have unequal flagella. Reproduction: sexual reproduction seldom occurs in isogamous type. Reserve food: Store food outside the chloroplast in the form of polysaccharide laminarin or chrysolaminarin. Example: Chrysodendron Class Bacillariophyceae ( Diatoms) Habitat: Found in both marine and freshwater habitats. Indicators of paleo-environmental conditions. Pigments: Chromatophores are yellow or golden brown. Structure: Unicellular, except for male gametes, diatoms lack flagella. Have unique cells as cell walls. Frustules sorround the diatom protoplasm are made up of polymerized opaline silica. Reproduction: some are sexual but their primary means of reproduction is asexual, by cell division. Reserve food: Fat and volutin Example: Pinnularia Class Cryptophyceae Habitat: Marine and freshwater Pigments: Chromatophores show diverse pigmentation and are usually parietal. May be some shades of brown. Structure: Flagella are slightly unequal, motile cells, and advanced forms are coccoid Reproduction: Isogamous Reserve food: Solid carbohydrates or starch Example: Chroomona  Current name is Pyrrophyta from Greek "pyrrhos" Class Dinophyceae meaning flame-colored. The name dinoflagellates refers to their forward-spiraling (Dinoflagellates) swimming motion. Habitat: Marine and freshwater Pigments: Chlorophylls a and c, golden brown pigments, including peridinin. Structure: Unicellular with two flagella, a nucleus with condensed chromosomes, chloroplasts, mitochondria and Golgi bodies. Theca- cell-covering structures Reproduction: sexual and asexual cell division Reserve food: oil and starch Example: Dinoflagellate Ceratium cause red tides some species produce neurotoxins Class Chloromonadineae Habitat: freshwater Pigments: Chromatophores are bright green in color and contain an excess of xanthophyll Structure: Motile with two almost equal flagella Reproduction: sexual reproduction is absent, longitidinal cell division Reserve food: oil Example: Trentonia Class Euglinineae Habitat: Freshwater Pigments: Chromatophores are pure green Structure: Motile, flagella may be one or two. Complex vacuolar system, large and prominent nucleus. Reproduction: Isogamous Reserve food: Polysaccharide and Paramylon Example: Eugle Class Phaeophyceae (Brown algae) Habitat: Mostly marine, dominating rocky shores in cold and temperature waters. Pigments: Brown accessory pigment fucoxanthin (cover a spctrum from pale- beige to yellow-brown to almost black). Structure: Most plants attain giant size, simple filamentous to bulky parenchymatous forms. Reproduction: Sexual reproduction ranges isogamous to oogamous. Reserve food: Mannitol, laminarin and fats. Example: Sargassum Class Rhodophyceae (Red algae) Habitat: Freshwater and marine Pigments: Contain chlorophyll a which is masked by phycobilin pigments bounf to proteins. Structure: Usually multicellular, lack flagella. Complex structure. Reproduction: sexual. Male organ produces non-motile gametes. Special spores suvh as carpospores are produced after sexual repeoduction. Reserve food: Floridean starch Example: Polysiohonia Class Cyanophyceae (Blue-green algae) Habitat: Freshwater and marine Pigments: Light-gathering pigments, phycobilins (bound to protein granules), phycobilisomes are attached to the photosynthetic membranes. Structure: Some of the filamentous show false or true branching, very rudimentary nucleus, no proper chromatophores, no motile stages. Reproduction: no sexual reproduction Reserve food: Sugars and glycogen Example: Spirulina Plays a role in elevating the oxygen level in the atmosphere of the early Earth.  FUNGAL CLASSIFICATION What is Fungi? What is Fungi? s Lack chlorophyll Do not perform photosynthesis Obtain nutrients through absorption Include yeasts, molds, and mushrooms Exhibit a complex life cycle with both asexual and sexual reproduction Can exist as unicellular or multicellular organisms Often have cell walls made of chitin Display a wide range of morphological forms and sizes Criteria for Classification 1. Structure of reproductive organs 2. Type of spores 3. Mode of reproduction (sexual/asexual) 4. Habitat (parasitic, saprophytic, mutualistic) Major Groups of Fungi 1. ZYGOMYCETES 2. ASCOMYCETES 3. BASIDIOMYCETES 4. DEUTEROMYCETES Zygomycetes Terrestrial (soil and decaying matter) Form thick-walled spores called zygospores Example includes Rhizopus (bread mold) Ascomycetes Largest group of fungi Produce spores in sac-like structure called asci Includes unicellular yeast and multicellular fungi Example includes Saccharomyces, Penicillium, and Aspergillus Basidiomycetes Known for producing spores on club-shaped structure called basidia Includes mushroom, puffballs, and bracket fungi Examples includes Agaricus, Amanita, Coprinus  Deuteromycetes Known as imperfect fungi due to absence of known sexual reproductive stage. Often grouped based on asexual reproduction (conidia formation) Many are pathogenic to plants and animals Examples includes Candida (yeast infection) and Trychophyton (athlete’s foot) THANK YOU.