Archaeo= ancient Bacteria = a unicellular micro-organism Kingdom Archaebacteria *the oldest living organisms on Earth *there is evidence that bacteria without nuclei lived on earth 3.5 billion years ago Archaeo= ancient Bacteria = a unicellular micro-organism

The 3 groups of Archaebacteria Methanogens Extreme Halophiles Thermoacidophiles

1) Methanogens: *They are bacteria that make methane *oxygen is a poison to these bacteria *They produce energy by converting H2 and CO2 into methane gas. *thrive in extreme environments geothermal springs (200 m below ground)

Methanogens have been discovered in two extreme environments on Earth Habitat: 1) Buried under kilometres of ice in Greenland 2) living in hot, dry desert soil.

Mars Some scientists have proposed that the presence of methane in the Martian atmosphere may be indicative of native methanogens on that planet http://www.space.com/scienceastronomy/051220_science_tuesday.html

2) Extreme Halophiles Name means: "salt-loving" bacteria live in environments with a very high salt concentration that would kill most other bacteria. *use salt to get energy *Found in the Dead Sea, Great Salt Lake, etc.

Colonies of “salty” bacteria built this!!! Habitat: Shark bay, Australia. rocky formations up to 1.5 meters high which were built by colonies of halophiles. Dead Sea Great Salt Lake

3) Thermoacidophiles Name Means: hot acid loving bacteria *Live in extremely hot (110 C) and acidic (pH 2) conditions. {The pH of water is about 7}

3) Thermoacidophiles Habitat: Found in hot springs in Yellowstone National Park, in volcanic vents on land, & in cracks on the ocean floor that leak scalding acidic water

Bacteria Of Boiling Hot Springs In Yellowstone National Park

Kingdom Eubacteria Eu = new or true Enterococci are normal inhabitants of the human gastrointestinal tract. Other major sites of colonization that may act as reservoirs for enterococci in hospitalized patients or nursing home residents include wounds and chronic decubital ulcers (pressure sores). Enterococci are seldom found in pure culture in wounds, but when they are, the wounds usually have no clinical evidence of infection. Generally, enterococci are present in mixed culture in soft tissue wounds. Asymptomatic women may also carry enterococci in high numbers in their vaginas, while 60% of men in hospitals may carry enterococci in their perineal or meatal areas. Enterococci are also hardy organisms, which allows them to survive well on environmental surfaces. Resistant enterococci have been isolated from surrounding areas of infected patients. Instruments such as electronic thermometers have been implicated in spreading this organism.  

Shape of bacterial cells Cocci - round bacterial cells. (cox-eye). b) Bacilli - rod-shaped bacterial cells. c) Spirilli (corkscrew) - spiral-shaped bacterial cells A B C

The overwhelming majority of bacteria are completely harmless A teaspoon of soil generally contains between 100 million and 1 billion bacteria Beneficial Bacteria The overwhelming majority of bacteria are completely harmless

5 types of friendly bacteria Nature’s recyclers In our body Food production Oil spills Nitrogen fixing bacteria

Saprotrophic eater-eat dead things for food Nature’s recyclers Saprotrophic eater-eat dead things for food *release nutrients back into the environment *man-made landscapes often lack these good bacteria A scanning electron micrograph of the aerobic soil bacterium Pseudomonas fluorescens. The bacterium uses its long, whiplike flagellae to propel itself through the water layer that surrounds soil particles.

2) Our bodies: Escherichia coli is a normal resident of the intestines in healthy people it helps us break down food waste products We pretty much depend upon E. coli in our intestines for our source of Vitamin K and B-complex vitamins.

3) Food production Streptococcus lactis bacteria convert milk to cheese by causing the souring of milk that begins the cheese making process, bacteria convert grapes to wine and then wine to vinegar The name for this process is FERMENTATION

Fermentation A chemical process that occurs when bacteria change sugar into various products It is a way that bacterial cells get energy without using oxygen Examples: Grapes----- Wine---------- Vinegar Milk -----Yogurt or cheese Cabbage ----- Sauerkraut

4) Oil spills Naturally occurring, oil-eating bacteria are used in response to crude oil spills without causing further harm to the environment.

How do oil spills cause harm? *Birds die from oil spills if their feathers are covered in oil. The bird will then be poisoned because it will try to clean itself. *Oil may also cause the death of an animal by entering the animal’s lungs or liver More than half of the seal pups living off the coast of Mid-Norway are contaminated with oil every spring

5) Nitrogen Fixing Bacteria some plants (peanuts, beans, peas) have pockets of bacteria in their roots can take Nitrogen from the air and make it useful for plants and animals by making the soil fertile helps farmers save $ on fertilizers plants use Nitrogen to make needed proteins

How do bacteria reproduce? Grow in number not in size Humans grow in size from child to adult Make copies of themselves by dividing in half Human parents create a child USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

How do bacteria eat? Photosynthetic bacteria Some make their own food from sunlight—like plants-autotrophic Some are scavengers-saprotrophic Share the environment around them Example: The bacteria in your stomach are now eating what you ate for breakfast Some are warriors (pathogens) They attack other living things-heterotrophic Example: The bacteria on your face can attack skin causing infection and acne Harmless bacteria on the stomach lining E. Coli O157:H7 is a pathogen USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

What is a pathogen? Bacteria that make you sick Why do they make you sick? To get food they need to survive and reproduce How do they make you sick? They produce poisons (toxins) that result in fever, headache, vomiting, and diarrhea and destroy body tissue USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006

Where do you get a pathogen? Indirect contact Contact with people who are sick Direct or indirect Food, Water, or other Surfaces that are contaminated Foods that could be contaminated USDA NIFSI Food Safety in the Classroom© University of Tennessee, Knoxville 2006 Direct contact