Microbial Nutrition Potassium K Calcium Ca 2 Sodium Na Magnesium Mg 2 Iron Fe 2

Microbial nutrition potassium k calcium ca 2 sodium

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Microbial NutritionPotassium (K+), Calcium (Ca2+) Sodium (Na+) Magnesium (Mg2+) & Iron (Fe2+and Fe3+)Mineral ions: Macronutrient elements:
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The Requirements for Growth Chemical requirements Carbon, Hydrogen Nitrogen, sulfur, and phosphorous Micronutrients/Trace elements Oxygen (aerobes or anaerobes) Growth factors Water Physical requirements Temperature pH Osmotic pressure
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Heterotrophs:(other-feeding) Use organics to supply carbon (e.g. carbohydrates like glucose C6H12O6, proteins, and lipids) Carbon source also typically supplies H and O Carbon source also supplies energy Autotrophs:(self-feeding) Use inorganic CO2as sole or principal carbon source Carbon source does not supply energySources of Carbon (& H, O)
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These elements can be obtained either from fixed sources or from inorganic sources Nitrogen (N):Amino acids, NH4+, NO3-, (also N2-fixation) Sulfur (S):S-amino acids (cysteine), sulfate (SO42-) Phosphorus (P) almost entirely from inorganic Pi(PO42-) Sources of N, P, S
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Typically transition metals (e.g. Mn, Fe, Mo, Cu, B, Co). Small Mineral requirement. Typically required in microgram (μg) quantities Often present in laboratory water and glassware Serve structural/catalytic roles in specific enzymesManganese SOD: involved in antioxidant defense Micronutrient (akaTrace Elements)
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Typically small organic compoundsAmino acids (protein synthesis) Purines/pyrimidines (nucleic acid synthesis) Vitamins (enzyme cofactors) Required in varying concentrations (μg-mg/liter) Growth Factors
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High O2Low O21 2 3 4 5 1: Obligate Aerobe Micrococcus luteus2: Obligate Anaerobe Methanobacterium formicicum3: Facultative (anaerobe/aerobe) Escherichia coli4: Microaerophile Spirillum volutans5: Aerotolerant anaerobe Streptococcus Reazurin Pink=oxidizedThe Effect of Oxygen (O2) on Growth Atm O2 ~20%
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Temperature ranges for different bacteria Classification Temperature Range (°C) Optimum Growth Temperature (°C) Psychrophile -10 to 20 10-20 Mesophile 10 to 45 20-40 Thermophile 40 to 75 >50 Hyperthermophile 65 to 120 >75
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Brock 12E Fig. 6.19 Temperature Classes of Microbes
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Effects of Temperature on Growth Psychrophilic = Cold loving; Mesophilic = middle living; Thermophilic = heat loving;
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pH requirements Most bacteria grow near neutrality, pH 6.5-7.5.
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  • Spring '08
  • keen
  • Bacteria, Growth medium, Bacterial growth, Solid media

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