Eucaryotes

- Fungi: yeast and mold

- Algae

Eucaryotes

Fungi

• Fungi are which need to take nutrients from the environment for living.

• They are larger than bacteria.

Fungi

Two major groups are yeast and mold.

Yeast

Yeasts are very important economically:

- Yeasts are responsible for fermentation of beer and bread. (Saccharomyces cerevisiae)

- Ethanol production

- Wastewater treatment:a mixed culture of yeasts Candida lipolytic Candida tropicalis, and Yarrowia lipolytica grown on hydrocarbons, or gas oil.

YeastYeasts are very important economically:

- Yeasts and Bacterium xylinum cultures produce Kombucha, fermented sweetened tea.

Yeasts: e.g.Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe

Yeast

http://www.sbs.utexas.edu/mycology/sza_images_SEM.htm

Eucaryotes-Fungi

Yeast is single-celled.

• Size: yeasts are 5 to 10 µm in diameter.

• Shape: .

• Reproduction: .

Eucaryotes-FungiYeasts

Reproduction: asexual and sexual.• Asexual reproduction is by either or

.

Budding: a small bud cell forms on the cell, which gradually enlarge and separate from the mother cells.

Most of the yeasts reproduce by budding.

Baker’s yeast, Saccharomyces cerevisiae.

Budding

Budding

Yeast Budding

http://www.sbs.utexas.edu/mycology/sza_images_SEM.htm

Yeast Reproduction

Asexual:

Fission: similar to budding but the cells grow to certain size and divide into two equal cells.Only a few yeast species are reproduced by fission. e.g.Schizosaccharomyces pombe

Sexual:

Eucaryotes-FungiMoldsMolds are filamentous and have a mycelial

structure.

Mycelium is highly branched system of tubes that contains mobile cytoplasm with many nuclei.

Hypha is long, thin filaments on the mycelium.

Mold

• Molds are very important economically:

- mushroom farming is a large industry in many countries. Agaricus bisporus

http://en.wikipedia.org/wiki/Agaricus_bisporus

Mold

- Food industry

The mixed culture including Penicillium sp. for cheese production.

Aspergillus niger for citric acid production.

- Antibiotics production.

Penicillium notatum

Eucaryotes-Fungi

Molds

Size:

When grow on solid surface, the filamentous form is 5-20 µm.

When grow in submerge culture, it can form aggregates and pellets, 50 µm-1mm.- Cause nutrient transfer problem in the pellet

Eucaryotes-Fungi

Mold Reproduction:

• Either by asexual or sexual means.

• Some molds form sexual spores which provide resistance against heat, freezing, drying and some chemical agents.

• Both asexual or sexual spores can germinate and form new hyphae.

Eucaryote-Algae

Algae are usually unicellular or plantlike multicellular organism.

• Like plants, most algae use the energy of sunlight to make their own food, a process called photosynthesis.

Algae lack the roots, leaves, and other structures typical of true plants.

• Algae contain chloroplast which is responsible for photosynthesis.

• Unicellular algae are considered in MicrobiologyE.g. Chlorophyta, Chrysophyta (brown, yellow-green algae)

Eucaryote-Algae

• They are in the size of 10-30 µm.

• Algae can reproduce asexually or sexually. Many of algae incorporate both sexual and asexual modes of reproduction.

• Algae contain alginic acid and agar.

VirusNot free-living organisms, of other living

cells.

• Size: 30-200nm.

• Can not capture or store free energy.

• Not functionally active except when inside their host cells.

• Can do harm but also be useful biotechnology tools (e.g. vaccines).

SARS Coronavirus virion

Virus• Bacteriophage or phage: virus infecting

bacteria.

• (Virus: virus infecting eukaryotes)

• Virus reproduction:- Virus contains genetic materials such as DNA and RNA which is covered by a protein coat called capsid.

- They can reproduce only by invading and controlling other cells as they lack the cellular machinery for self-reproduction.

Section Summary

• Organism cells are highly diverse in terms of their adaptation to the living environment:

Temperature, pH, oxygen, moisture, nutrients

• Shapes (bacteria): Coccus, Bacillus and Spirillum

Primary Classification

Cellular Organism

Eucaryotes Procaryotes Virus

not free-living organisms Have nuclear membrane and membrane-bound organelles?

Yes No

Primary Classification

Cellular Organism

Eucaryotes Procaryotes Virus

Organelles:Mitochondria: powerhouse Endoplasmic reticulum: protein and lipid synthesisLysosome: nutrient digestion enzymesGolgi: protein secretion and modificationVacuoles: food digestion, osmotic regulation and waste product storageChloroplasts: photosynthesis

not free-living organisms Have nuclear membrane and membrane-bound organelles?

Yes No

Fungi: yeast and mold

Algae:

(asexual or sexual reproduction)

Primary Classification

Cellular Organism

Eucaryotes Procaryotes Virus

not free-living organisms Have nuclear membrane and membrane-bound organelles?

Yes No

Cytoplasmic granules:- Ribosome: protein synthesis- Storage granules: source of key metabolites, including polysaccharides, lipids and sulfur granules.- Capsule- Pili- Flagella

Eubacteria: gram-positive, gram-negative, non-gram, actinomycetes and cyanobacteria

Archaebactria: methanogenHalogenthermoacidophiles

Mostly asexual reproduction

Primary Classification

Cellular Organism

Eucaryotes Procaryotes Virus: reproduce in the host cell

Eubacteria:

Gram-positive bacteriaGram-negative bacteriaNon-gram bacteriaActinomycetes Cynaobacteria

Fungi: yeast, mold

Algae:

Reproduction: asexual or sexual

Archaebateria:

methanogenHalogenThermoacidophiles

not free-living organisms Have nuclear membrane and membrane-bound organelles?

Yes No

Asexual reproduction