at temperature greater than 50c microbial growth was inhibit

at temperature greater than 50c microbial growth was inhibited. What could be the possible effects of higher than normal temperature on microbial growth. Give two.

Solution

1) Protein denaturation - Every activity inside the cell is carried by enzymes and other proteins. Their activity ceases at temperature above 55 deg, and destroyed permanently above 65 deg, which either stops the growth, or kills the microbe.

2) DNA denaturation - DNA is denatured above 75-80 deg.

3) Destruction of native structures of lipids and lipo-polysaccharides (cell wall and membrane) - They are heat labile and denature fast above 55-60 deg.