Chapter 5: Microbial Diversity - Eucaroytic Microbes

Algae

• Photosynthetic eukaryotes found in Protista Kingdom.

• Found in various environments: freshwater, saltwater, wet soil, and rocks.

• Lack true roots, stems and leaves.

• Cells contain:

  • Cytoplasm, cell wall, cell membrane, nucleus, plastids, ribosomes, mitochondria, and Golgi bodies.

  • Some have pellicle, stigma (eyespot), and flagella for movement.

Phycology

Study of algae

Type of Algae | Diatoms

• a type of algae that is unicellular, live in freshwater and seawater.

• Important in phytoplankton.

• cell walls made of silicon dioxide (glass).

Type of Algae | Dinoflagellates

• a type of algae that is unicellular, flagellated algae.

• responsible for red tides and producing oxygen.

Type of Algae | Spirogyra

• a type of algae that is filamentous green alga found in plants

Type of Algae | Chlamydomonas

• a type of algae that is unicellular, biflagellated with one chloroplast and a stigma.

Type of Algae | Volvox

• a type of algae that is colonial alga forming hollow spheres with coordinated flagellar movement.

Type of Algae | Euglena

• a type of algae that is unique blend of algal and protozoan features.

• Photosynthetic, with a stigma and flagellum for light detection and movement.

• Can ingest food in the absence of light.

Environmental Impact of Algae

Clogs filters and pipes in water systems when nutrient levels

Uses of Algae

• Food (source of minerals and iodine).

• Fertilizers, emulsifiers in food products.

• Biofuel research (algae are nearly 50% oil.)

• Agar for bacterial growth media (derived from red marine algae).

Prototheca

• Rare cause of human infections (protothecosis)

  • genus of algae in the family Cholorelaceae.

  • Found in soil and enters wounds, especially on feet.

  • Causes subcutaneous lesions that can become crusty, warty.

  • In severe cases, may cause debilitating or fatal infections in immunocompromised individuals if it spreads through the lymphatic system.

Phycotoxins

Algae in other genera secrete _____, which is harmful to humans, fish, and animal

Protozoa

• Eucaryotic organisms, classified under the Protista Kingdom (alongside algae).

  • Unicellular organisms ranging in size from 3 to 2,000 micrometers.

  • Found in soil and water; possess animallike characteristics.

Protozoology

Study of protozoa

Protozoologist

Person studying protozoa

Protozoal Cell Structure

• Contain eucaryotic structures: Cell membrane, nucleus, ER, mitochondria, Golgi bodies, lysosomes, centrioles, and food vacuoles.

• Some have: Pellicles, cytostomes, contractile vacuoles, pseudopodia, cilia, or flagella

Protozoa Feeding Mechanism | No chlorophyll

a feeding mechanism of protozoa that cannot make food via photosynthesis.

Protozoa Feeding Mechanism | Cytosome

a feeding mechanism of protozoa that ingests food through a primitive mouth (e.g., Paramecium).

Protozoan Life Cycle | Trophozoite

a stage of protozoan life cycle that is focused on motile, feeding, and dividing stage

Protozoan Life Cycle | Cyst

a stage of protozoan life cycle that is focused on being non-motile, dormant survival stage (life bacterial spores)

Parasitic Protozoa

• absorb nutrients from their host,

• some are pathogens, causing diseases like malaria, giardiasis, African sleeping sickness, and amebic dysentery.

Symbiotic Protozoa

• Mutualistic relationships

• For example, ____ in the termite’s gut digest wood, benefiting both the termite and protozoa

Protozoan Locomotion Types | Amebas

• a locomotion type of protozoa where it moves via pseudopodia (false feet)

  • e.g., Entamoeba histolytica causes amebic dysentery or Amoebiasis

Protozoan Locomotion Types | Ciliates

• a locomotion type of protozoa where it moves using cilia, exhibiting oarlike motion

  • e.g., Balantidium coli, which causes dysentery

Protozoan Medical Examples | Entamoeba histolytica

a protozoa that causes amebic dysentery

Protozoan Medical Examples | Naegleria fowleri

a protozoa that causes primary amebic meningoencephalitis

Protozoan Medical Examples | Acanthamoeba spp.

a protozoa that causes eye infections

Protozoan Medical Examples | Balantidium coli

a protozoa that is pathogenic ciliate causing dysentery in developing countries

Flagellated Protozoa (Flagellates)

• Use whiplike flagella for movement

• Each flagellum is anchored by a basal body (also called kinetosome or kinetoplast)

• Movement is a wavelike motion

Flagellated Protozoa (Flagellates) | Trypanosoma brucei subspecies gambiense

a flagellated protozoa that is transmitted by the tsetse fly, causes African sleeping sickness

Flagellated Protozoa (Flagellates) | Trypanosoma cruzi

a flagellated protozoa that causes Chagas’ disease (American trypanosomiasis)

Flagellated Protozoa (Flagellates) | Trichomonas vaginalis

a flagellated protozoa that causes trichomoniasis, a sexually transmitted infection (STI) affecting both male and female genital tracts

Flagellated Protozoa (Flagellates) | Giardia lamblia (Giardia intestinalis)

a flagellated protozoa that causes giardiasis, a persistent diarrheal disease

Sporozoa (Nonmotile Protozoa)

Movement: Lack pseudopodia, flagella, or cilia

Sporozoa | Plasmodium spp.

• a sporozoa that cause malaria, transmitted by female Anopheles mosquitoes

  • E.g., Plasmodium falciparum causes malaria in the Philippines

Sporozoa | Cryptosporidium parvum

• a sporozoa that causes cryptosporidiosis, severe diarrheal disease in immunosuppressed patients, especially those with acquired immunodeficiency syndrome (AIDS)

  • Notable outbreak: 1993 in Milwaukee, Wisconsin, affecting over 400,000 people

Sporozoa | Babesia spp.

a sporozoa that causes babesiosis

Sporozoa | Cyclospora cayetanesis

a sporozoa that causes cyclosporiasis, a diarrheal disease

Sporozoa | Toxoplasm gondii

a sporozoa that causes toxoplasmosis

Fungi

Eukaryotic organisms that lack chlorophyll and vascular tissue, living by decomposing and absorbing organic matter

Fungi’s Habitat | Saprophytic

a fungi habitat that lives on dead organic matter

Fungi’s Habitat | Parasitic

a fungi habitat that lives on plants or animals

Importance of Fungi | Beneficial

Production of cheeses, beer, wine, drugs (e.g., cyclosporine), and antibiotics (e.g., penicillin).

Importance of Fungi | Harmful

Causes food spoilage (e.g., jams, leather, plastics).

Characteristics of Fungi

• Eucaryotic organisms (yeasts, moulds, mushrooms).

• Non-photosynthetic: Lack chlorophyll.

• Cell wall contains chitin (not cellulose like plants).

• Some are unicellular (yeasts), others grow as filaments called hyphae, forming a mycelium

Fungi’s Form of Reproduction | Asexual Spores

• can germinate through a single spore

• conidia produced by reproduction of fungi

Fungi’s Form of Reproduction | Sexual Spores

• need 2 spores to form diploid

• zygospores and ascospores are produced by fungi’s reproduction

Spores

Resistant to environmental extremes and allergens for many.

Classification of Fungi | Zygomycotina (Zygomycota)

• a fungal classification that refers to lower fungi

  • e.g., bread moulds

Classification of Fungi | Chytridiomycotina

a fungal classification that refers to water moulds and soil organisms

Classification of Fungi | Ascomycotina (Ascomycota)

• a fungal classification that refers to higher fungi

• e.g., some yeasts, plant disease fungi

Classification of Fungi | Basidiomycotina (Basidiomycota)

a fungal classification that includes mushrooms, toadstools

Classification of Fungi | Deuteromycotina (Fungi Imperfecti)

• a fungal classification that has no known sexual reproduction

• e.g., aspergillus, penicillium

Yeast

• Unicellular organisms that belong to the Fungi kingdom

• Eucaryotic, unicellular organisms lacking mycelia.

• Common Names, individual ________cells are known as blastospores or blastoconidia.

Budding

yeasts’ primary method of reproduction

Yeast Reproduction | Pseudohyphae

a yeast reproduction that pertains to strings of elongated buds that resemble hyphae but are not true hyphae.

Yeast Reproduction | Chlamydospores

a yeast reproduction that is thick-walled, sporelike structures produced by some yeasts.

Yeast Habitat

found in soil water and on the skins of many fruits and vegetables

Yeast Fermentation | Saccharomyces cerevisiae

Commonly known as baker’s yeast

Yeast Fermentation | Anaerobic Conditions

a yeast fermentation that ferments sugars to produce alcohol

Yeast Fermentation | Aerobic Conditions

a yeast fermentation that breaks down sugars to produce carbon dioxide and water, used for leavening bread

Yeast Nutritional Value

A good source of vitamins and proteins for humans

Pathogenic Yeasts | Candida albicans

a pathogenic yeast that is most frequently isolated yeast in clinical specimens and a common human pathogen

Pathogenic Yeasts | Cryptococcus neoformans

a pathogenic yeast that is a notable human pathogen

Laboratory Identification | Colony appearance

a laboratory identification of yeast that is similar to bacterial colonies

Laboratory Identification | Identification Technique - Wet Mount

a laboratory identification of yeast that mixes colony with water/saline and examining under a microscope

Laboratory Identification | Identification Technique - Gram Staining

a laboratory identification of yeast where yeasts are usually larger (3 to 8 µm) and oval-shaped; some may show budding

Fleshy Fungi

• Examples

  • Mushrooms, toadstools, puffballs, bracket fungi

• Structure

  • Consists of a network of mycelium and a fruiting body that releases spores

• Medical Significance

  • Some are toxic and can cause severe health issues, including permanent liver and brain damage

Mycoses

refers to fungal infections

Mycoses | Superficial Mycoses

a type of mycoses that affect outer layers like skin, hair, nails

Mycoses | Cutaneous Mycoses

• a type of mycoses that affect living layers of skin

• e.g., tinea or ringworm

Mycoses | Subcutaneous Mycoses

• a type of mycoses that affect deeper skin layers and tissues

• e.g., Madura foot

Mycoses | Systemic Mycoses

affect internal organs, potentially causing widespread infection

Systemic Mycoses

• Blastomycosis

• Histoplasmosis

• Coccidioidomycosis

Dimorphic Fungi

Organisms that have the ability to switch between two morphologies during their lifecycle: yeast and mold

Dimorphism

• Can exist as yeasts or molds depending on temperature

  • Yeast form at 37° C (body temperature)

  • Mold form at 25°C (room temperature)

Lichen

a symbiotic relationship between an alga or cyanobacterium (photobiont) and fungus (mycobiont)

Type of Lichen | Foliose

a type of lichen that is leaflike

Type of Lichen | Crustose

a type of lichen that is crust-like

Type of Lichen | Fructicose

a type of lichen that is shrubby

Type of Lichen | Gelatinous

a type of lichen that is gel-like

Slime Mold

• Saprophytes that lack chlorophyll

• Not associated with Human Disease

Slime Mold | Cellular Slime Mold

a type of slime mold that start as independent amebae, aggregate into a “slug” during nutrient shortages.

Slime Mold | Plasmodial Slime Molds

a type of slime mold that form large masses of multinucleated protoplasm called a plasmodium