Diversity Of Microorganisms 2

Part 2 EUKARYOTIC MICROBES

ALGAE Photosynthetic eukaryotes Some algal cells have pellicle, a stigma and

flagella Sizes range from tiny, unicellular, microscopic to large and multicellular. Found in freshwater, salt water, in wet soil or wet rocks. Most are photoautotroph

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Vaucheria (B) Diatom (C)Navicula (D) Oocystis (E) Scenedesmus (F)Spirogyra (G) Nostoc (H)Oscillatoria

Phylum Bacillariophyta Diatoms Microscopic, unicellular,

live in both freshwater and salt water Cell walls contain SiO2 Chlorophyll a and c,

carotene, xanthophylls Attractive, geometric and varied appearance

Phylum Dinoflagellata Dinoflagellates Microscopic, unicellular,

flagellated and often photosynthetic Chlorophyll a and c, carotene, xanthins Neurotoxins cause paralytic shellfish poisoning

Red Dinoflagellate

Phylum Chlorophyta Green algae Cellulose cell walls Unicellular or

multicellular Chlorophyll a and b Store glucose polymer Gave rise to plants

Spirogyra

Characteristics Spirogyra- filamentous alga Chlamydomonas- unicellular, biflagellated, one

chlorophyll and stigma Volvox- multicellular alga, biflagellated cells arranged to form a sphere Desmids- unicellular, resembles a banana

Chlamydomonas

Volvox

Desmid

Phylum Phaeophyta Brown algae Cellulose + alginic acid

cell walls Multicellular Few are microscopic Chlorophyll a and c, xanthophylls Store carbohydrates Harvested for algin

Alginin Alginate absorbs water quickly, which makes it

useful as an additive in dehydrated products such as slimming aids, and in the manufacture of paper and textiles. It is also used for waterproofing and fireproofing fabrics, as a gelling agent, for thickening drinks, ice cream and cosmetics, and as a detoxifier that can absorb poisonous metals from the blood.

Sargassum

Giant Kelp

Phylum Rhodophyta Red algae Cellulose cell walls Most multicellular Chlorophyll a and d,

phycobiliproteins Store glucose polymer Harvested for agar and carrageenan

Agar

Carrageenan

Agar is used to make

Carrageenan sed in the

jellies, puddings and custards. Used throughout the world to provide a solid surface containing medium for the growth of bacteria and fungi. Used for electrophoretic separation in agarose gel electrophoresis

food and other industries as thickening and stabilizing agents. Desserts, ice cream, milk shakes, sweetened condensed milks, sauces. Pharmaceuticals — used as an inactive excipient in pills/tablets

Porphyra

Gibsmithia

Phylum Chrysophyta Golden algae Some colorless, but the

vast majority are photosynthetic Important in lakes Facultatively heterotrophic Chlorophyll c, carotenoids and xanthophylls

Synura

Licmophora

Aulacoseira

Phylum Euglenophyta Euglenoids Possessed both algae and

protozoan characteristics Contain stigma and flagellum Chlorophyll a as the primary photosynthetic pigment and chlorophyll b and carotenoids Remaining two-thirds are either facultatively or, like animals, fully heterotrophic Euglena acus

Strombomonas

Phacus elegans

Medical Significance Prototheca – causes protothecosis, lives on

soil. Can enter wounds on feet Small subcutaneous lesion to crusty, wartylooking lesion. Debilitating or fatal if enters the lymphatic system Phycotoxins – secretion, poisonous to humans fish and other animals

Typical pond water ALGAE and PROTOZOA

A.Amoeba sp. B.Euglena sp. C.Stentor sp. D.Vorticella sp. E.Volvox sp. F.Paramecium sp.

PROTOZOA Eukaryotic, unicellular, animal-like, and motile Feeding state is a trophozoite Some produce cysts (dormant stage) Asexual reproduction by fission, budding, or

schizogony Sexual reproduction by conjugation

No cell walls, pellicle serves for protection Contractile vacuole (in Amoeba and

Paramecium), pumps out water Some are parasites, break down and absorb host nutrients Pathogens – (malaria, giardiasis, African Sleeping sickness and amebic dysentery Symbiotic relationship (in termites)

Ciliates Move by cilia Complex cells Balantidium coli is

the only human parasite Vorticella

Paramecium

Amoebae Move by pseudopods, Phagocytosis Like WBCs

Entamoeba – dysentery

and extraintestinal abscesses Acanthamoeba- eye infection

Entamoeba

Acanthamoeba

Flagellates Multiple flagella Giardia lamblia Trichomonas

vaginalis (no cyst stage)

Trypanosoma

Euglena

Sporozoa No pseudopodia,

flagella or cilia Non-motile Plasmodium ssp.causes malaria Cryptosporidium parvumcryptosporodiosis

Plasmodium vivax

Plasmodium falciparum

Cryptosporidium parvum

FUNGI Eukaryotic, Kingdom Fungi Aerobic or facultatively anaerobic, found almost

everywhere Some are Saprophytic, others Parasitic Most are decomposers (organic matter/ leather and plastics, spoilage of jams, pickles, etc.) some beneficial (prod’n cheese, wine, drugs: cyclosporine & penicillin) Mycology is the study of fungi

Economic Effects of Fungi Fungi

Positive Effects

Negative Effects

Saccharomyces Bread, wine, beer

Food spoilage

Trichoderma

Cellulose used for juices and fabric

Taxomyces

Taxol production

Cryphonectria parasitica (chestnut blight) Ceratocystis ulm (Dutch elm disease)

Entomorphaga

Gypsy moth control

Decomposers Versus Saprophyte Decomposers- breaks material down Saprophyte (saprobe)- absorbs nutrients from

dead and decaying organic matter All saprophytes are decomposers. Not all decomposers are saprophytes. Parasite obtain nutrients from living organisms. Saprophytes obtain nutrients from dead organisms.

Characteristics No chlorophyll Cell wall contain chitin Many are unicellular (yeast) Others grow as filaments called hyphae, which

intertwine to form a mass called mycelia (thallus). Some fungi have septate hyphae Others have aseptate hyphae, which contains multinucleated cytoplasm (coenocytic).

Microscopic appearance of various Fungi

A. Aspergillus fumigatus B. Aspergillus flavus C. Penicillium sp. D. Curvularia sp. E. Scopulariopsis sp. F. Histoplasma capsulatum

Reproduction Budding, hyphal extension or formation of

spores. Fungal spores: sexual and asexual spores Sexual spores- fusion of two gametes (ascospores, basidiospores, zygospores) Asexual spores- not formed by fusion (conidia) Some species can produce both sexual and asexual spores Fungal spores are very resistant.

Fungal Life Cycle/ Reproduction

Conidiospores/ Conidia

Coccidioides immitis

Aspergillus flavus Candida albicans

Classification Divided into five phyla Based on their mode of reproduction Lower fungi- Zygomycotina and

Chytridiomycotina Higher fungi- Ascomycotina and Basisiomycotina Fungi Imperfecti- Deuteromycotina

Classification According to Sexual Reproduction

Lower fungi

Higher fungi

Fungi Imperfecti

Yeast Unicellular fungi Fission yeasts divide

symmetrically Budding yeasts divide asymmetrically Pseudohypha- string of elongated buds Chlamydosphoresthick-walled spore-like

Yeasts

Left:Longitudinal sect. of a budding yeast; Right: Candida albicans A. Chlamydospores, B. Pseudohyphae, C.budding yeast cells Blastospores

Candida albicans

Saccharomyces cerevisiae

Colonies of Candida albicans on blood agar plate

Molds The fungi seen in

water & food Fungal thallus consists of hyphae; a mass of hyphae is a mycelium.

The Great Potato Famine Phytophthora infestans

– potato blight mold in Ireland Killed Ireland’s potato

crops in 1845, 1846 and 1848. More than 1 million died of starvation Antoine de Baryproved that fungus caused the blight

Importance of Molds Antibiotics from Penicillium and Cephalosporium. Many additional antibiotics discovered by isolating molds that inhibit bacteria. Antibiotics can be chemically altered to increase spectrum of activity ex.: Synthetic penicillins: ampicillin, amoxicillin, & barbenicillin Some for production of large quantities of enzymes

(amylase, citric acid, organic acids) Molds provide flavor in diff. types of cheeses (, camembert, limburger).

Fleshy Fungi Large fungi Mushroom, toadstools,

puffballs and bracket fungi Many mushrooms are edible, but some are extremely toxic and may cause permanent liver and brain damage or death if ingested

Amanita muscaria

Mushroom

Toadstools

Puffballs

Bracket fungi

Fungal Infections (Mycoses) Superficial mycoses Cutaneous mycoses Opportunistic mycoses

Subcutaneous mycoses Systemic mycoses

Outermost areas (skin) Living layer of the skin Caused by normal microbiota or fungi that are normally nonpathogenic Beneath the skin Deep within body

Tinea pedis

Oral thrush

Dimorphic Fungi Pathogenic dimorphic

fungi are yeastlike at 37°C and moldlike at 25°C Histoplasma capsulatum (histoplasmosis) Sporothrix schenckii (sporotrichosis) Coccidioides immitis (coccidiomycosis) Blastomyces dermatitidis (blastomycosis)

Mycetomas

Teleomorphs and Anamorphs Teleomorphic fungi: Produce sexual and asexual spores. Anamorphic fungi: Produce asexual spores only. rRNA sequencing places most in Ascomycota, a few are

Basidiomycota Penicillium Stachybotrys, Coccidioides, Pneumocystis (systemic mycoses) Candida albicans (Cutaneous mycoses)

Lichens Mutualistic

combination of an alga (or cyanobacterium) & fungus – Symbiotic Alga produces and secretes carbohydrates, fungus provides holdfast Found in various colors, black, brown, orange, various shades of green, depending on combination of alga and fungus Classified as protists

Fungus+Alga = Lichens

Slime Molds Found in soil, rotting logs Have both fungal and protozoal chars. &

interesting life cycles Start out in life as independent amoebae Slug- motile, multicellular form Slug becomes a fruiting body (stalk and spore cap) From each spores emerges and amoeba

Slime Molds Cellular slime molds

Resemble amoebas,

ingest bacteria by phagocytosis Cells aggregate into stalked fruiting body. Some cells become spores

Plasmodial slime molds

• Multinucleated large

cells

• Cytoplasm separates

into stalked sporangia

• Nuclei undergo

meiosis and form uninucleated haploid spores

Cellular Slime Mold

Plasmodial Slime Mold

Plasmodial Slime Mold- Fuligo septica

Lycogala epidendrum

Arcyria cinerea

Hemitrichia calyculata

Metatrichia vesparium

Quiz next meeting!!