TOPIC #: IMPORTANT BACTERIA Study Important features about these bacterla: a. St

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TOPIC #: IMPORTANT BACTERIA Study Important features about these bacterla: a. Streptococcus pneumonia b. Lactobacillus acldophilus c. Coxielia burnetil d. Listeria monocytogenes e.Myco f. Streptococcus thermophles bacterlum tubercuiosis TOPIC #2: MICROBIAL LIFE & ENVIRONMENT a. List and recall vital characteristics of Microbial Life b. Define Minlmum, Optimum, or Maximum conditions. c. How do they affect Microbial growth? TOPIC #: FORMS OF MICROBIAL LIFE a. Study forms of Microbial Life b. Explain why Viruses may be Living/Non-living things c. Describe unique characteristics of: Prions TOPIC 4: DIFFERENTIAL STAINING a. Review Steps, Dyes, and reagents b. Identify chemical groups for dyes TOPIC : THE GRAM STAIN a. Analyze steps and outcomes for Gram Stain. b. Keep track of reactions and final results for Gram Staln TOPIC 6: GRAM STAIN &PEPTIDOGLYCAN;: Explain Gram Reaction by its a. Location b. Amount .Thickness TOPIC #: COMPARISON OF GRAM POSITIVE AND GRAM NEGATIVE BACTERIA TABLE 4.1,PAGE 84 a. Teichoic Acids Lipteichois acids b. Cell Wall Lipids d Lip-Polysaccharides TOPIC #8: TEMPERATURE & MICROBIAL GROWTH a. Name Microbial Temperature Groups b. Define Temperature ranges for each group .Analyze their effects on Human health.

Explanation / Answer

Topic 1: Important features of Bacteria:

a. Streptococcus pneumonia-
- it is the gram-positive bacteria
- found in diplococci
- they are immovable (non-motile) organisms

b. Lactobacillus acidophillus-
- it is gram-positive bacteria
- obtains its energy by converting sugar glucose into lactose therefore known as Lactobacillus
- grows at low pH below 5.0
- used in the manufacture of yoghurt and lactic acid

c. Coxiella burnetii-
- it is the gram-negative bacteria
- occurs in cocco-bacillu shapes
- survives in the hosts monocyte and macrophage
- causes Q-fever

d. Listeria monocytogenes-
- it is the intracellular gram-positive bacteria
- it is the food born pathogen which survives and replicates in both phagocytic and non-phagocytic cells
- it causes the sickness of high mortality rate known as listeriosis
- it is motile, non-spore forming and anaerobic bacteria

e. Mycobacterium tuberculosis-
- this is the obligate parasite, rod shaped
- this is aerobic, non-motile, and non-spore forming bacteria
- commonly causes Tuberculosis, deasese affecting lungs in humans

f. Streptococcus thermophiles-
- it is the anaerobe, gram-positive bacteria, non-motile
- found in fermented products like milk and used in the production of yoghurt

Topic 2 Microbial life and Environment-

a. Characteristics of microbial life-
- Microorganisms are differentiated into prokaryotic, eukaryotic and viruses
- Prokaryotes are bacteria and archea which are the earliest forms, they are anucleus that is single-celled
- Eukaryotic cells are larger than prokaryotes, contain nucleus and other cells well organized like mitochondria, ribosomes, endoplasmic reticulum etc.
- Viruses are very very smaller than the both. they are dependent cannot reproduce on their own, the genetic material is wrapped around the protein capsule.

b. The growth conditions of bacteria depend on various factors like pH, temparature, physical and chemical factors ranging from minimum to maximum. Minimum temperature is the lowest temparature at which the microbe grows.
At optimim temparature rapid growth of microbe occurs whereas the highest temparature occurs where the microbe grows at maximum temperature.

c. Minimal temp: Psychrophiles - -20 deg C to +10 deg C, eg: clamydomonas, methanogenum
Optimal : Mesophiles 20 to 40 deg C, eg: escherichia coli, streptococcus
Maximum: Psychrotrophs above 15 to 20 deg C, eg: pseudomonas, clostridium
Thermophiles 50 or above, 80 deg C, eg: thermococcus

Topic 3. forms of microbial life;

a. forms of bacterial life are Bacteria, Algae, Fungi, Protozoa, Virus
b. Viruses are tiny living creatures but considered as non-living because they are non-active, do not contain any cell organelle and do not produce energy of their own.They require host cell for reproduction.
c. Prions do not contain nucleic acid, derived from protenacious inferctious diseases. They are smaller than viruses. They can destroy nucliec acid of pathogens. they are coil shaped known as alpha helices.

Topic 4 Differential staining:
a. Gram stain, Acid fast stain, Endospore stain, Capsular stain

Topic 5 Gram stain:

- place slide with heat fixed smear on staining tray
- flood the smear with crystal violet gently and leave for a few minutes
- tilt and gently wash the stain with distilled or tap water
- again flood the smear with grams iodine and leave for 1 minute
- again wash the stain as before so that the smear appears purple circle
- decolourize with ethyl alcohol or acetone apply 5 drops of alcohol drops and rinse with water
- flood with safranin and leave for 45 secs
- again rinse gently so that the smear does not disappear
blot dry the smear and obsrve in light microscope under oil immersion

b. result : gram +ve will appear purple and gram -ve appears pink.

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