MCB-150-Exercise-1-Post-Lab.pdf - ENVIRONMENTAL FACTORS AFFECTING MICROBIAL GROWTH Aguilar Gerald Bondad Saina Marquez Jeremy Meclat Vanessa

MCB-150-Exercise-1-Post-Lab.pdf - ENVIRONMENTAL FACTORS...

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ENVIRONMENTAL FACTORS AFFECTING MICROBIAL GROWTH Aguilar, Gerald Bondad, Saina Marquez, Jeremy Meclat, Vanessa
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Introduction Microorganisms are affected by several environmental factors such as: 1. Nutrients 2. Moisture content 3. pH 4. Temperature 5. Osmotic Pressure
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Objectives The objective of this exercise is to determine the effect of various environmental factors on growth of different microbial types
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Results and Discussion
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Temperature
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4 oC 35 oC 20-30 oC 45 oC Effect of temperature 1. G. stearothermophilus 2. Micrococcus luteus 3. Escherichia coli 4. Pseudomonas putida
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SUMMARY
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CARDINAL TEMPERATURE characteristic growth temperature for microorganisms range of temperatures that a particular microorganism can tolerate Below minimum - metabolically inactive; growth is not possible Above maximum- growth is not possible Optimal temperature - organisms exhibit their highest growth and reproduction rates
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ADAPTATIONS Adaptations to Low Temperatures 1. Higher proportions of unsaturated and/or short chain lipids 2. Greater polar and lesser hydrophobic amino acid content 3. “Cold - shock” proteins and cryptoprotectants
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ADAPTATIONS Adaptations to High Temperatures 1. High proportions of saturated lipids in membranes 2. Unusual amino acid sequences within proteins 3. High proportions of guanine and cytosine in the DNA
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OSMOTIC PRESSURE
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4 oC 20-30 oC Effect of osmotic pressure (NaCl) 1. Saccharomyces cerevisiae 2. Penicillium 3. Pseudomonas putida 4. Staphylococcus warneri 25% 0.5% 15%
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SUMMARY
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