microbiology

·         Escherichia coli has a generation time of 20 minute when growing under optimum conditions. Starting with 10³ cells in a batch culture, how many cells are produce after 24 hours,?

The generation time (g) for Escherichia coli is 20 minute.

The number of generations (n) that a population of Escherichia coli  cells will pass through in 24 hours is :

We need to find Nt. That is the number of cells produced after time t (24 hours) starting with a population of 10³ ceels (NO).

Using the equation

Rear ranging :

(72 x 0.3010) + 3 = log Nt

Log Nt = 24.672

Nt = antilog 24.672

Nt = 4.7 x  cells = 47 kg cells

·         How do you think about that,?

I think weight 47 kg cells can be grow in a erlenmeyer, because factor affecting enzymes activity, the enzyme working is influenced by substrate concentration, enzyme concentration, temperature, pH, and inhibitor.

ü  Substrate  concentration : the enzyme molecule is much larger than the substrate molecules, then bonding the enzyme substrate complex will be more difficult to form when  the concentration of small substrate, may be substrate concentration make cell can be grow in a erlenmayer with weight cells 47 kg or impossible.

ü  Enzyme concentration : the addition of the enzyme concentration will accelerate the reaction, if agar in Erlenmeyer very much than bacteria, can be grow bacteria very much from before.

ü  Temperature : since enzymes are protein is highly sensitive to temperature changes, rising temperatures will accelerate the chemical reaction because the increase in temperature causes the addition of substrate and enzyme kinetic energy, and high temperature also affect the enzyme itself.

ü  pH : enzyme molecule has an ionic group which can affect the pH of the environment.

ü  Inhibitor : competitive inhibitor are generally in the form of a compound whose structure is similar to the substrate and  if after 24 hours bacteria culture will very more and can be make full erlenmeyer with bacteria culture.