Chapter4 Microbial growth Environmental factors on growth Growth in natural environment
Chapter4 Microbial growth Environmental factors on growth Growth in natural environment
Effect ofenvironmental factors on growth Water availability, pH, temperature, oxygen concentration, pressure, radiation and a number of other environmental factors influence microbial growth Yet many microorganismS, and particularly bacteria, have managed to adapt and fourish under environmental extremes that would destroy most organisms
Water availability, pH, temperature, oxygen concentration, pressure, radiation, and a number of other environmental factors influence microbial growth. Yet many microorganisms, and particularly bacteria, have managed to adapt and flourish under environmental extremes that would destroy most organisms. Ef ect of environmental factors on growth
Effect of temperature on bacterial growth rate Effect of Temperature on the growth of E coli Bacteria grow over a Optimum temperature 30 of growth(37.C) range of temperatures; they do not reproduce below the =20 minimum growth temperature nor above the maximum growth Minimum 1.0 temperature Maximum temperature. Within the of growth 8°C temperature of growth temperature growth range 48°C there is an optimum growth 30 4050 temperature at which bacterial °F405060708090100110120 reproduction is fastest Temperature
Bacteria grow over a range of temperatures; they do not reproduce below the minimum growth temperature nor above the maximum growth temperature. Within the temperature growth range there is an optimum growth temperature at which bacterial reproduction is fastest. Effect of temperature on bacterial growth rate
Microorganisms are classified as psychrophiles, mesophiles. thermophiles, and extremethemophiles based on their optimal growth temperature. Temperature effect: Extreme 1. Psychrophile (0-20C Thermophile 2. Mesophile (45-15C 3. Thermophile (40-700C) 4. Hyperthermophile g (65-95 5. Extrem hyper- thermophile (80-120C) 01028030405060060 termperature(C)
Microorganisms are classified as psychrophiles, mesophiles. thermophiles, and extremethemophiles based on their optimal growth temperature. Temperature effect: 1. Psychrophile (0-20oC) 2. Mesophile (45-15oC) 3. Thermophile (40-70oC) 4. Hyperthermophile (65-95oC) 5. Extrem hyperthermophile (80-120oC)
Temperature A most important factor influencing the growth is the temperature sensitivity of enzyme catalyzed reactions High temperature 1. Denature enzymes transport carries and other proteins 2. Microbial membranes are also disrupted by temperature extremes 3. The lipid bilayer melts and disintegrates
Temperature • A most important factor influencing the growth is the temperature sensitivity of enzyme catalyzed reactions. • High temperature: 1. Denature enzymes, transport carries, and other proteins. 2. Microbial membranes are also disrupted by temperature extremes. 3. The lipid bilayer melts and disintegrates