BACTERIA Kingdom Eubacteria True Bacteria Bacteria are located

BACTERIA

Kingdom Eubacteria (True Bacteria) Bacteria are located everywhere – air, water, land, and living organisms including people. There are TRILLIONS in your body right now! E. Coli O 157: H 7 can make you very sick. Streptococcus can cause strep This E. coli helps you digest food.

General Characteristics: 1. All are unicellular (one-celled structural level) 2. All are prokaryotic - cells that lack nucleus and membrane-bound organelles (PRO = NO!) 3. All have cell walls – NO cellulose in cell walls 4. Some require O 2 (aerobic) while some do NOT require O 2 (anaerobic)!

5. Bacteria are much larger in size than viruses.

6. Bacteria usually have one of three different cell shapes: Coccus (Sphere-shaped) Bacilli (rod-shaped) Spirillum (Spiral-shaped) Ex: Streptococcus Ex: Lactobacillus Ex: Spirillium

What shape? bacillus spirillum coccus bacillus spirillum

Outer surface is sometimes most complex! • Some have a polysaccharide capsule Cytoplasm Genetic Material Cell Wall • May have flagella for movement • May have fimbriae/pili for adhering in their environment Cell Membrane E. coli Flagella

Bacteria…

To reproduce… Undergo binary fission

For energy… • Some make their own food from sunlight —like plants Photosynthetic bacteria • Some are scavengers – Share the environment around them Ex: Bacteria in your stomach are now eating what you ate for breakfast • Some are warriors (pathogens) – They attack other living things • Example: The bacteria on your face can attack skin causing infection and acne Harmless bacteria in the stomach

Causes Disease by: 1. Destroying cells of infected organisms by breaking the cells down for food.

2. Releases toxins (poisons) which destroy cells of infected organism. 3. Must have access to new hosts to spread.

Different Hosts

What are some common pathogens? • Pathogenic E. coli (like O 157: H 7) E. coli O 157: H 7 – Found in ground beef, contaminated fruits and vegetables • Salmonella – Found in raw meats, poultry, eggs, sprouts, fruit and vegetables • Listeria – Found in deli foods, lunch meats, smoked fish and vegetables USDA NIFSI Food Safety in the Classroom © University of Tennessee, Knoxville 2006 Listeria

Helpful or Harmful? https: //www. youtube. com/watch? v=1 v wf. Gx. VWYNk

Are all bacteria pathogens? • No, most are harmless • Some are even helpful – Examples of helpful bacteria: • Lactobacillus: makes cheese, yogurt, & buttermilk and produces vitamins in your intestine • Leuconostoc: makes pickles & sauerkraut • Pediococcus: makes pepperoni, salami, & summer sausage

A Closer Look – Helpful Bacteria www. bioweb. usu. edu Pediococcus - used in production of fermented meats Lactobacillus casei – found in human intestines and mouth to improve digestion Leuconostoc cremoris – used in the production of buttermilk and USDA NIFSI Food Safety in the Classroom © sour cream University of Tennessee, Knoxville 2006 Lactobacillus bulgaricus – used in the production of yogurt

Bacteria can also be beneficial as decomposers!

Oil spills - bacteria can digest small oil spills

Salt Lake City Kingdom Archaebacteria a. First known prokaryotes. Archaebacteria (archae=ancient) b. Live in very harsh environments (known as extremophiles)– high salt content, hot temperatures, acidic or alkaline environments Hydrothermal vents Geyser

c. Live in intestines of animals, especially cows and other grazing animals – methanogens Produce methane gas – greatly affects our atmosphere by combining d. Same size and with O 2 to make CO 2 for shape as Eubacteria, photosynthesis but different biochemical makeup methanogenic archaebacteria