2. Archaebacteria and Eubacteria

3. Important Features -all are prokaryotes -all have plasmids (small circular packages of DNA) -most have peptidoglycan in their cell walls -flagella are made with a globular protein called flagellin

4. Cytosol Granules (Small chunks of food)

6. Locomotion (Methods of Movement) u Bacterial Flagellum u Pili- short, thin appendages

7. Bacteria E. coli

8. Nutrition-DO NOT NEED TO COPY u Autotrophs- manufacture organic compounds –Photoautotrophs- use light energy & CO 2 –Chemoautotrophs-use inorganic substances like H 2 S, NH 3, and other nitrogen compounds u Heterotrophs- obtain energy by consuming organic compounds –parasites- get energy from living organisms –saprobes (saprophytes)- get energy from dead, decaying matter; also called decomposers

9. Oxygen Preferences u obligate aerobes- must have oxygen u obligate anaerobes- cannot live in oxygen u facultative anaerobes- can grow with or without oxygen

10. 2 Bacteria Kingdoms u Kingdom Archaebacteria - are ancient bacteria that live in extreme environments u Kingdom Eubacteria - are generally referred to as bacteria or germs, and are considered more recent. Most types of bacteria belong in this kingdom.

11. The Archaebacteria: u do not have peptidoglycan in their cell walls u have ribosomes similar to eukaryotes u have unique lipids in their plasma (cell) membranes

12. The Archaebacteria also: u have some genes that resemble eukaryotic genes u usually are not pathogenic (they don’t usually make us sick!) u live in extreme environments: –high concentrations of salt –extremes of pH and temperature

13. 3 Archaebacterial Groups u Methanogens-turn H 2 and CO 2 into methane u Halophiles-salt u Thermoacidophiles = live in extremely hot, acid environments

14. Methanogens u anaerobic bacteria that get energy by turning H 2 and CO 2 into methane u live in mud, swamps, and the guts of cows, humans, termites and other animals

15. Halophiles u are organisms that live in environments with extremely high salt concentrations –some extreme halophiles can live in solutions of 35 % salt. (seawater is only 3% salt!) u halophile means “salt loving” u most halophiles are aerobic and heterotrophic

16. Diversity of Halophilic Organisms u halophiles are found in salt lakes, salt marshes, subterranean salt deposits, dry soils, salted meats u the Red Sea was named after the halobacterium that turns the water red during massive blooms.

17. Halophile Environments Owens Lake, Great Salt Lake, coastal splash zones, Dead Sea

18. Thermoacidophiles u Like temperature and pH extremes –Hot = up to 3740ºF –Cold = down to 34ºF –Acid = pH 2 –Basic = pH 9 u they are chemoautotrophs u the first Extremophile was found about 30 years ago

19. Extreme Temperatures u Thermophiles - High temperature = 60-80 0 C –Thermal vents and hot springs –May go hand in hand with chemical extremes u Psychrophiles - Low temperature –Arctic and Antarctic »Most rely on photosynthesis

20. Thermophile Environments Hydrothermal Vents in the ocean, and Obsidian Pool in Yellowstone National Park

21. Psychrophile Environments Alan Hills Ice Field: Antarctica

22. Chemical Extremes u Acidophiles - Acidic –Again thermal vents and some hot springs u Alkaliphiles - Alkaline –Soda lakes in Africa and western U.S. u Halophiles - Highly Salty –Natural salt lakes and manmade pools –Sometimes occurs with extreme alkalinity

23. Acidophile Environments

24. Alkaliphile Environments e.g. Mono Lake alkaline soda lake, pH 9, salinity 8%

25. Examples of Unusual Habitats u The bacterium pseudomonas was found living on a desert plant in the Negev Desert. The plant secretes salt through salt glands on its leaves. u Bacillus was found in the nasal cavities of desert iguanas. These iguanas have salt glands in their nasal cavities that secrete KCl brine during osmotic stress.

26. IDENTIFICATION of BACTERIA – 3 MAIN SHAPES u Baccili u Cocci u Spirillum

27. Identification – cell walls u There is a method used to tell apart two types of cell walls in eubacteria, called Gram staining. u Gram-positive bacteria stain violet –These bacteria have 1 cell membrane surrounded by a thick peptidoglycan wall which holds the color well. u Gram-negative bacteria stain pink –These bacteria have a thin peptidoglycan wall between 2 membranes. The wall is too thin to hold the color as well.

28. Bacterial diseases u Bacteria produce disease in 1 of 2 ways: –Damage cells and tissues of the organisms it is infecting by breaking down the cells for food. Example- tuberculosis OR –Releasing toxins that will travel throughout the body, which interfere with the normal activity of the infected organisms cells. Example- strep throat

29. Preventing bacterial disease u Vaccines- injection of a weakened form of a pathogen that prepares the body to produce immunity to the pathogen u Antibiotics- given after infection, they block the growth and reproduction of bacteria

30. Controlling bacteria u How can we control the presence of bacteria? –Sterilization with heat –Disinfectants –How we store food –How we process food

31. They aren’t all bad! u We need bacteria for: –Decomposition- help recycle materials in nature –Nitrogen fixation- bacteria convert nitrogen gas to a form of nitrogen that the plants can use –Good bacteria in foods –E. coli in our intestines