Eukarya: Eukaryotic Microorganisms Algae: Phototrophic eukaryotic microorganisms Fungi: Nonphotosynthetic eukaryotic microorganisms that contain rigid.

Eukarya: Eukaryotic Microorganisms• Algae: Phototrophic eukaryotic microorganisms• Fungi: Nonphotosynthetic eukaryotic microorga

nisms that contain rigid cell walls• Slime molds: nonphototrophic eukaryotic micro

organisms that lack cell walls and that aggregate to form fruiting structures (cellular slime molds) or masses of protoplasm (acellular slime molds)

• Protozoa: unicellular eukaryotic microorganisms that lack cell walls

Phylogenetic tree of Eukaryabased on 18S ribosomal RNAsequence comparisons.

Cells of microsporidia anddiplomonads are phylogeneticallymost ancient of known Eukaryaand contain a nucleus but lackmitochondria

Eukaryotic Microorganisms

• Algae

• Fungi

• Slime Molds

• Protozoa

AlgaeMost Algae are green in color

Color of AlgaeMost algae are green in color. A few algae appear brown or red as other pigments including carotenoids are present that mask green

Classification of Algae

• Chlorophyll

• Carbon Reserve Polymers

• Cell Wall Structure

• Type of Motility

绿藻

蜂窝藻

金藻

暗藻

甲藻

红藻

眼藻

Fungi: Molds, Yeasts and Mushrooms

• Habitats diverse: aquatic in fresh water or marine, terrestrial in soil or on dead plant, a few are human parasitic

• Have rigid cell walls (resemble plant cell walls architecturally, not chemically) containing chitin (some with mannans, galactosans, chitosans instead of chitin)

• Fungal cell walls are 80-90% polysaccharide, with proteins, lipids, polyphosphates and inorganic ions making up the wall-cementing matrix

Classification of Fungi

• Based on

–morphological properties

–sexual life cycles

Molds: filamentous fungi• Hypha (hyphae): a single filament• Mycelium: hyphae grow together formed tufts• Conidia: asexual spores, pigmented, resistant to d

rying

Yeasts: unicellular fungi (ascomycetes)

• Division: budding• Do not form filaments• Some form filaments• Some can mate.

Mushroom: filamentous fungi that typically form large structures called fruiting bodies

Basidiosporereleased frombasidia

Slime molds: phenotypically similar t

o both fungi and protozoa

Acellular slime molds growing ona decaying log

Acellular slime molds growing onan agar surface

Cellular slime molds: vegetative forms composed of single amebalikecells. Acellular slime molds: vegetative forms composed of indefinitesize and shape

Dictyostelium discoideum in various life stages

Protozoa• Colorless• Motile• distinguished from prokaryotes by their greater size

and eukaryotic nature• distinguished from algae by their greater lack of

chlorophyll• distinguished from yeasts and other fungi by their

mobility and lack of cell wall• distinguished from slime molds by their lack of fruiting

body formation• Many of them are parasitic in other animals and

human

Amoeba

Ciliate （ Paramecium）

Flagellate （ Dunaliella）

Sporozoan (Plasmodium vivax)

Mastigophora: the flagellates• Motile by the action of flagella• Many are free-living, some are parasitic, or pathog

enic for animals, including human• They are rather small, about 20 microns in length• Trypanosoma gambiense is the species that cause

the fatal and chronic African Sleeping Sickness

The most important pathogenicMastigophora are the trypanosomes,which causes African Sleeping Sickness. It lives and grows in human bloodstream, and transmitted from hostto host by the tsetse fly, Glossina sp., abloodsucking fly found over in certainparts o Africa.

Sarcodina: The Amebas

• Naked in the vegetative phase, the foraminefera (带孔虫） secretes a shell during vegetative growth

• Many amoebas are parasites of human and other vertebrates

• In some cases, they produce ulceration of the intestinal

• tract, which results in a diarrheal conditions called amebiasis

Ciliophora: the ciliates• Possess cilia in some stage of their lief cycle• Have two kinds of nuclei: micronucleus for inheritance and sexual re

production: macronucleus for production of mRNA for various

Aspects of cell growth andfunctionThe best known ciliate genus isParameciumMany ciliates obtain food by ingesting particular materialsthrough a distinct oral region or mouthMany Paramecium speciescontain endosymbioic bacteriathat synthesize vitamins or other growth factors.

Sporozoa (孢子虫）• Obligate parasites• Lack of motile adult stages• Absorb food in soluble form through outer wall• Produce sporozoites for transmission to new host• Most important: coccidia, parasites of birds and plasmodia

(malaria parasites)

Balantidium coli, a ciliatedprotozoan that causes a dysentry-like disease in human,The dark blue stained structureis the macronucleus

SARCOMASTIGOPHORA（肉鞭动物门）

LOCOMOTION运动

Subphylum Mastigophora鞭毛虫纲 : locomotion by one or more fl

agella

Subphylum Sarcodina肉足虫纲 : locomotion and food gathered by pseudopodia (f

alse foot)

- includes the Amoeba

The AMOEBA

APICOMPLEXA端复胞器门

Ciliophora纤毛虫纲

Clockwise from top right: Flagellate, amoeba, and ciliate. (Photos: Rebecca Stott)

Stalked ciliate. (Photos: Rebecca Stott)

Crawler ciliate. (Photos: Rebecca Stott)

Free swimmer. (Photos: Rebecca Stott)

Flagellates. (Photos: Rebecca Stott)

Potifers. (Photos: Rebecca Stott)

Aqualtic earthworms. (Photos: Rebecca Stott)

Nematodes. (Photos: Rebecca Stott)