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Unformatted text preview: Experiment 2-1: Ubiquity of Microorganisms(pgs 27-29), 2-2 and 2-4 (pgs 30-37;39): Cultural Characteristics
Purpose: To demonstrate the wide distribution of bacteria. Also, to show the importance of
aseptic technique (so pure, uncontaminated cultures can be obtained). Classification
The five kingdom system The three domains of life refer to figure 3-10 on page 73 Domain Archaea
All: prokaryotic Divisions: The methanogens The extreme halophiles The hyperthermophiles Domain Bacteria
Prokaryotic Seldom photosynthetic Domain Eucarya
All: have nuclei Group 1: Anaerobes, 70S ribosomes, No golgi, NoMt Group 2: Aerobes, 80S ribosomes, Golgi, Mt, Chloroplasts King Animalia Characteristics of Bacteria:
Organisms that are the most widely distributed, the simplest in morphology, the smallest in size, the most difficult to classify, the hardest to identify 1. Ubiquitous found all over and in every environment such as soil, water, on plants, on animals, or humans 2. Simple morphology (shape) Three major bacterial morphologies: Rod (bacillus) Spherical (cocci) Helical and curved 3. Small size (microscopic): 0.5m to 2 m 4. Difficult to classify and identify due to the varied nature of all the bacteria 5. Prokaryotic and belong to the Kingdom Monera (share it with the cyanobacteria) 6. Generally non-photosynthetic do not have chlorophyll a which is found in plants; have bacteriochlorophyll Materials: (per student)
1-3 TSA plate(s) (25mL) (depending on exposure method used - refer to chart in lab manual changes packet) 1 Blood Agar plate or Brain Heart Infusion Agar (BHIA) plate (25mL) 1 TSB broth (5mL) 1 Sterile cotton swab Methods:
1. 2. 3. Expose the TSA plate(s) according to the method listed for you student bench number Expose the Blood Agar (or BHIA) plate by coughing hard on the open plate, as if you were trying to bring up sputum Inoculate the TSB broth by swabbing a fomite and placing the cotton swab in the tube for incubation Label the plates and tube properly and incubate in your TA's incubator at 37oC for 48 hours. 4. 1 Proper labeling of a plate: -on the bottom of the plate where the agar is located Proper incubation of a plate: -inverted, with agar facing upwards 1. Prevents contamination from condensation 2. Prevents smearing of colonies with condensation 3. Also, some bacteria are osmotic susceptible Proper labeling of a tube: -On the glass just below the cap
Initials Media Inoculation Date TA name Fomite any object, surface, or even a body part Most organisms are free living and do not reside on a particular host Reservoir any area where a microbe resides and serves as a potential source of infection Most microorganisms are opportunistic pathogens they are normally harmless but can cause infection when given the chance. EX. 2-2: Cultural Characteristics/ EX. 2-4: Growth Patterns in Broth
Use the descriptive terms from EX 2-2 and EX. 2-4 to describe the growth present on the Blood Agar plate, TSA plate(s), and in the TSB tube. 2 ...
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