Background• Biologists have long

organized living things into large groups called kingdoms.

• There are six of them:– Archaebacteria– Eubacteria– Protista– Fungi– Plantae– Animalia

Some recent findings…

• In 1996, scientists decided to split Monera into two groups of bacteria:

Archaebacteria and Eubacteria• Because these two groups of bacteria were

different in many ways scientists created a new level of classification called a DOMAIN.

• Now we have 3 domains1. Bacteria2. Archaea3. Eukarya

5 common characteristics used for comparison among living organisms:

• Cell type – 2 kingdoms are prokaryotic; 4 kingdoms are eukaryotic

• Cell wall – 4 of the 6 kingdoms have a cell wall

• Body type – unicellular vs. multicellular

• Nutrition – autotrophic vs. heterotrophic

• Reproduction – sexual vs. asexual

KingdomArchaebacteria

Both kingdoms of bacteria have species that are microscopic; humans can’t see them unless we stain them and then look at them under the microscope. The pictures you see are magnified many times!!

The Domain Archaea

• “ancient” bacteria• Some of the first

archaebacteria were discovered in Yellowstone National Park’s hot springs and geysers.

Basic Facts• They live in extreme environments (like

hot springs or salty lakes) and normal environments (like soil and ocean water).

• All are unicellular (each individual is only one cell).

• No peptidoglycan in their cell wall.• Some have a flagella that aids in their

locomotion.

Some weird things about this kingdom…

• Most don’t need oxygen to survive

• They can produce ATP (energy) from sunlight

• They can survive enormous temperature extremes

• They can survive high doses of radiation (radioactivity)

• They can survive under rocks and in ocean floor vents deep below the ocean’s surface

• They can tolerate huge pressure differences

3 Main Types

Methanogens

Thermoacidophiles

Halophiles

Methanogens• They release methane (CH4) as a waste product

• Many live in mud at the bottom of lakes and swamps because it lacks oxygen

• Some live in the intestinal tracts of animals to help break down food

• Others like to hang out in the stomach

• Your intestinal gas is a waste product caused by bacteria in the body breaking down the food you eat—that’s why farts don’t smell sweet!

Significance of methanogens• They could play a role in

garbage/sewage cleanup by having methanogens eat garbage. – The methane waste the

bacteria produce after eating the garbage or sewage could be used as fuel to heat homes.

• Some landfills already employ this method—the only problem is that it’s expensive.

Thermoacidophiles• Live in the dark• Live without oxygen• Like to live in superheated water with

temperatures reaching 750 deg F• Prefer environments that are very acidic (between

pH of 1-3)

• Live in a chemical soup of hydrogen sulfide (H2S) and other dissolved minerals (rotten egg smell)

Thermo = temperature

Acidophil = acid loving

The interior layers of the Earth are made up of many different types of metals (iron, copper). The black color is caused by a chemical reaction of the metals with the ocean water. In extreme temperatures and pressures, this is where some thermoacidophiles like to live.

Black Smokers

Other thermoacidophiles like to live in hot springs or geysers. Hot springs are pools of hot water that have moved toward earth's surface. The source of their heat is the hot magma beneath and they can reach temperatures as high as 400 degrees Fahrenheit

http://www.nps.gov/archive/yell/oldfaithfulcam.htm

Old Faithful erupts more frequently than any of the other big geysers. Its average interval between eruptions is about 91 minutes. An eruption lasts 1 1/2 to 5 minutes, expels 3,700 - 8,400 gallons of boiling water, and reaches heights of 106 - 184 feet.

Halophiles

• Can live in water with salt concentrations exceeding 15%

• The ocean’s concentration is roughly 4%

• Halo = saltphil = loving

The Great Salt Lake in Utah

The Great Salt Lake in Utah• It is interesting to note that the Great Salt Lake

is actually three to five times saltier than the ocean.

• Every year, members of the salt industry extract about 2.5 million tons of sodium chloride (salt, NaCl) from the lake.

• The Great Salt Lake has no fish. The largest aquatic critters in the Great Salt Lake are brine shrimp.

• Given that the salty water can be corrosive to metal, motorized boats are not very popular at Great Salt Lake State Park. Additionally, since the salt content of the Great Salt Lake increases the water’s density, water skiing and jet skiing is not very common.

KingdomEubacteria“true bacteria”

Bacteria vs. EukaryaBacteria Eukarya

Internal compartmentalization

No nucleus, few organelles

Nucleus with many organelles

Cell size Very small; microscopic

Small; still microscopic but 10 to 100 times bigger than bacteria

Number of cells unicellular multicellularChromosomes Single, circular DNA

strandMany chromosomes made up of DNA

Reproduction Asexually by binary fission; Sexually by conjugation

Asexually by mitosis and Sexually by meiosis

Flagella Common in most species

Seldom seen in species; longer and stronger than bacteria

Metabolic diversity Can survive with or without oxygen

Require oxygen to survive

Bacterial Cell Shapes

Bacillus (rod-shaped)

Coccus (round-shaped)

Spirillum (spiral-shaped)

Obtaining Energy

• Most scientists classify bacteria based on how they obtain energy:

PhotosynthesizersChemoautotrophsHeterotrophs

Photosynthesizers• A significant fraction of the world’s photosynthesis is carried out by bacteria

• Cyanobacteria are blue-green bacteria that contain chlorophyll in their cell membrane

• Cyanobacteria are thought to have made the Earth’s oxygen atmosphere

Chemoautotrophs

• Breakdown chemicals found in the soil; they use those chemicals for nutrition

• The bacteria’s waste products act as fertilizer and helps with agriculture

• A handful of soil can have up to 10 billion bacterial organisms

Heterotrophs• Most types of Eubacteria are heterotrophic

• Together with fungi, they serve as primary decomposers for the environment by releasing nutrients back to the soil after living things have died.

REPRODUCTION1. Asexual – binary fission (single

cell splits into 2 identical new cells)

2. Sexual – conjugation – trading DNA

Pathogenic Bacteria

• Your body is a treasure chest of wealth just waiting to be discovered by bacteria.

• Bacteria have evolved various ways of entering your body and taking what they need in order to survive

• In some cases, the competition for the resources in your body can result in you becoming ill.

Gram Staining• Gram staining is used to identify bacteria with

extra membranes. These bacteria are more resistant to damage (antibiotics).

• Gram positive stain purple

• Gram negative stain red» (extra membrane made of peptidoglycan)

Bacteria are harmful in two ways:1. #1 - Bacteria can

metabolize their host by using different parts of the body as their food source.

Tuberculosis is a less common bacterial infection that attacks the lungs of humans.

Mycobacterium tuberculosis is the bacteria that uses the lung tissue as a food source.

The warm, moist environment allows the bacteria to reproduce and populate the lungs.

#2 - Bacteria cause disease by secreting chemical compounds called toxins into their environment.

Humans are most affected when food is not properly prepared. Food poisoning is the common name given to people who get severely sick after eating something that wasn’t cooked well.

Most types of toxin bacteria can be killed by boiling water and cooking foods at recommended temperatures.

Kitchen and surface antibacterial products also help in ridding our house of these relentless pests.

We’ve talked about why bacteria is BAD…Is there anything GOOD about bacteria?

• Act as decomposers• Live within our digestive tract

(called probiotics)• Many foods we eat are

processed by bacteria (pickles, buttermilk, cheese, sauerkraut, olives, vinegar, etc.)

• Bacteria can be used in mines to breakdown the surrounding rock and leave behind the useful ore/metal.

• Used to breakdown chemical/oil spills

Antibiotics• In 1928, Alexander

Fleming noticed a fungus growing on a Petri plate that was growing bacteria.

• He saw that the bacteria did not grow near the fungus.

• He concluded that the fungus was secreting a substance that killed the bacteria.

• He later called the secretion penicillin.

• Penicillin is one of many medicines that help fight bacterial infections.

Antibiotic-Resistant Bacteria

Problem #1:• Because bacteria can multiply very quickly, a 7-

10 day course of antibiotics might not kill all of the bacteria.

• The bacteria that remain become resistant and may mutate their DNA and reproduce more cells.

• The new cells are now resistant to the antibiotic and make it harder to treat an infection the next time around.

Problem #2:• Another problem in

society is related to people not taking their prescribed course of pills.

• Sometimes if people start to see improvement in their symptoms they stop taking their medication.

• This leaves more opportunity for the bacteria not yet killed by the antibiotic to reproduce and create resistant cells.

Problem #3:• Do antibacterial

soaps really work?• Regular, routine use

of these types of soaps may be doing more harm then good.

• The bacteria that are commonly found on our skin may become resistant to the antibacterial chemicals put in the soaps.