Introduction to Bacteria Ubiquity of Bacteria Ubiquity yoobikwitee
Introduction to Bacteria
Ubiquity of Bacteria • Ubiquity [yoo-bik-wi-tee] : the state or capacity of being everywhere • The ubiquity of bacteria refers to the concept that microorganisms are EVERYWHERE • Bacteria are the most widely distributed organisms in the biosphere. – Soil, water, air – Normal flora: microorganisms that live on and in our body that do not cause harm – Only place where bacteria is not found are in areas that are purposely made sterile • Body fluids • Clean rooms • Sterilized/autoclaved equipment
What makes an organism a bacteria? • Bacteria are primarily defined by their cellular structure and size – Lacks a defined nucleus that is surrounded by a nuclear membrane – Lack complex organelles (i. e. mitochondria) – Cell wall contains peptidoglycan – Approx 0. 2μm in diameter ( comparison RBC = 6 -8 μm)
Handling Bacterial Cultures • Aseptic technique: keeps unwanted microorganisms out (reduces contamination) – Disinfecting work area – All tools used to handle bacteria need to be sterile • Loops/Needles: flamed in the incinerator to sterilize • Tubes, plates, and any other tools: autoclaved to kill any existing bacteria – Keep all cultures covered until ready for use – Be aware of your area-if you are unsure if your tools have been compromised then start over
Characterizing Microorganisms I’m Lonely!! Binary Fission Colony
Characterizing Microorganisms • Colony morphology – Form: surface view – Elevation: height – Margin: edge – Color • Smell • Cell morphology – Size – Shape – Gram stain reaction
• Look over Slides #4 -11 • Be sure you can tell the morphology of each organism – Bacillus/rod, cocci, spirochete • Know the correct spelling and nomenclature of each microorganism • There are pictures of the slides on the website
Shapes of Bacteria • Bacillus (bacilli) – generic term to describe the morphology of any rod-shaped bacterium. short bacilli Pseudomonas long bacilli Bacillus with endospores
Shapes of Bacteria • Coccus (cocci) – any bacterium that has a spherical, ovoid, or generally round shape cocci in clusters Staphylococci in chains Streptococci
Shapes of bacteria • Vibrio – Possessing a curved-rod shape (comma shape)
- Slides: 10