BACTERIA

I. Kingdom Eubacteria (True Bacteria) Bacteria are located everywhere – air, water, land, on and in living organisms, including people. A. General Characteristics: 1. All are unicellular 2. All are prokaryotic (no nucleus)

3. Interaction with Oxygen Obligate Aerobes - require oxygen for respiration, need oxygen to grow and survive Obligate Anaerobes - must avoid oxygen, they will die in its presence Facultative Anaerobes - can use oxygen when it is available, but can also do without it 4. Autotrophs or heterotrophs

B. Example pili (attachment) ribosomes genetic material cytoplasm flagella (movement) cell membrane (inner) Capsule (protection) cell wall (outer)

Example: E. coli Cytoplasm Genetic Material Cell Wall Cell Membrane Flagella Example: E. coli

Bacteria are much larger in size than viruses, but smaller than cells.

C. Cell Wall – all eubacteria have cell walls composed of peptidoglycan protein + -

1. Gram staining determines the type of cell wall Gram +  Purple/violet Gram -  Red, more complex cell wall Gram-positive Staph aureus at the top Gram-negative Pseudomonas aeruginosa at the bottom.

How do antibiotics work? 2. Antibiotic used to cure bacterial infection depends on: Gram + or Gram – 3. Antibiotics work by disrupting the formation of the peptidoglycan cell wall. 4. Gram – bacteria are harder to treat due to complexity of cell wall.

D. Causes disease: 1. destroys cells – of infected organisms by breaking them down for food 2. releases toxins – that travel throughout the body interfering with normal activity of the host Scanning electron microscopy image of bacteria (the cylindrical objects) attached to host cells. These bacteria are in the process of injecting the host cells with the toxins. (Credit: Hebrew University illustration)

E. Three Shapes 1. cocci – round staphlo - cluster 2. bacilli – rod strepto - chain 3. spirilla – spiral

Coccus (Sphere-shaped) Ex: Streptococcus Bacilli (rod-shaped) Ex: Lactobacillus Spirillum (Spiral-shaped) Ex: Spirillum

What shape? bacillus spirillum coccus spirillum coccus bacillus

F. Survival 1. tough outer coat forms around DNA and cytoplasm of some bacteria – endospore can survive a long time and in harsh conditions ex: tetanus in soil

Diversity: Bacteria Survive in Hostile Environments by: 2. Capsules (slime layers) - help evade immune system and adhere to surfaces 3. Pili – hair-like projections 4. Flagella - one or more tail-like structures

G. Importance: 1. Beneficial a. breakdown and obtain energy from dead materials -- decomposers

Example: Compost piles need microorganisms (ex Example: Compost piles need microorganisms (ex. bacteria) to decompose (breakdown) matter.

b. dairy industry - bacteria in 2:08 minute video yogurt, sour cream and cheese From Sourdough to Swiss Cheese: Bacteria in Food

c. Oil spills – digest petroleum, can clean up small oil spills

d. Genetic engineering— Recombinant DNA – insert human genes into bacteria plasmid Ex: bacteria produce human insulin for diabetes

relationship where both organisms benefit-- mutualism e. relationship between two different organisms-- symbiosis relationship where both organisms benefit-- mutualism example: E. coli in intestines helps us digest food and make vitamins. In return, human intestines provide food and shelter for bacteria. (This strain of E. coli is different from the E. coli strain that causes food poisoning.)

Infectious Diseases Caused by Bacteria 3:07 minute video Infectious Diseases Caused by Bacteria

Anthrax Tetanus Strep Throat 2. Harmful : Pathogens: disease causing agents – pneumonia, strep throat, tuberculosis, tooth decay, bad breath, anthrax, tetanus, staph, bacterial meningitis Anthrax Strep Throat Tetanus

3:15 minute video Antibiotics

b. food spoilage and poisoning – caused by Salmonella and Staphylococcus (handout) c. antibiotics fight bacterial infections, but often have – digestive side effects some bacteria are able to survive in presence of antibiotics that kill other bacteria – antibiotic resistant bacteria

Note: This is why doctors tell you to take the entire amount of medicine given even if you start to feel better because if not, bacteria will have the chance to evolve and become antibiotic resistant.

Geyser II. Kingdom Archaebacteria Salt Lake City First known prokaryotes- Archaebacteria (archae=ancient) b. Live in very harsh environments – Halophiles: “salt loving”, use osmotic pressure and chemical substances to help control the amount of salt inside the cell. Located The Great Salt Lake, Dead Sea, evaporation ponds. Thermophiles: contain adaptations that allow them to live in areas of high temperature (113-252 °F). Located Yellowstone National Park, deep sea hydrothermal vents Salt Lake City Hydrothermal vents

Methanogen bacteria: Live in intestines of animals, especially cows and other grazing animals – They convert C and H into methane (CH4) gas which reacts with O2 to produce CO2, which affects our – atmosphere by producing CO2 for photosynthesis

Industrial Uses for Bacteria 3:12 minute video Industrial Uses for Bacteria

Reproduction: Binary Fission One cell splits into two cells, offspring are genetically identical to parent.

Reproduction: Conjugation A form of sexual reproduction where bacteria exchange genetic information before dividing, offspring have new genes genetically different to parents

Reproduction: Spore Formation A spore is a haploid reproductive cell with a hard outer coat. They form a new organism without the fusion of gametes.

Reproduction: Transformation Bacteria incorporate genes from dead bacteria Transduction - viruses insert new genes into bacterial cells. This method is used in biotechnology to create bacteria that produce valuable products such as insulin