CTable 7.-4/Table 72) 2) Include nutrient requirements 3) Give examples autotroph, heterotroph, chemoautotroph, photoautotroph, chemoheterotroph, photoheterotroph,...

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Environmental factors that control microbial growth are as follows:

1] Physical factors = Temperature ,pH ,Osmotic pressure,hydrostatic pressure & radiation

Temperature- is most important factor that determines the rate of growth,multiplication,survival & death of all living organisms.High temperature damage microbes by denaturing enzymes,transport carriers & other proteins.Microbial membranes are distrupated by extreme temperatures.
pH= refers to negative logarithm of hydrogen ion concentration.Microbial growth is strongly affected by the pH of the medium.Drastic variations in cytoplasmic pH disrupt the plasma membrane or inhibit the activity of enzymes & membrane transport proteins.
Osmotic pressure = is the minimum pressure which needs to be applied to a solution to prevent the inword flow of water across a SPM
Hydrostatic pressure = most organisms are always subjected to pressure of 10 atmosphere .the pressure can reach to 600 to 1100 atm in the deep sea with temperatures about 2 to 3 degree.organisms can survive & adapt at these extreme conditions & many are barotolerant.
Radiation= electromagnetic radiation of various types of bombards our world.As the wavelength of electromagnetic radiation decreases ,the energy of radiation increases gamma rays & X rays are much more energetic than visible light or infrared waves.UV light kills all kinds of microbes due to its short wavelength & high energy.

2] Chemical factors = Oxygen,carbon,nitrogen,phosphorous,sulfur

Oxygen= An aerobe is an organism able to grow in the presence of atmospheric O2 & the ones that grow in its absence is an anaerobe.

Answer 2