Question

Explain in detail how (1) temperature, (2) nutrient level, 3) oxygen level, and 4) the antibiotic chloramphenicol affect bacteria. It is not sufficient to say that the condition slows or speeds up growth, but clearly indicate the underlying physiological reason why each condition would decrease or increase growth. What impact does each condition have on bacterial cells physiologically?

Answer 1

1) Temperature : Generally, an increase in temperature will increase enzyme activity. But, if temperature get too high, enzyme activity will diminish and the protein (the enzyme) will denature. Every bacteria has specific growth temperature requirements which is largely determined by the temperature requirements of its enzymes.

2) Nutrient level : Nutrients are necessary for bacterial growth and play a vital role in the proper cultivation of bacteria in the laboratory or for proper growth in their natural environments. Different kinds of bacteria need different amounts of nutrients to survive including carbon, nitrogen, phosphorus, sulfur, and metal ions.

3) Oxygen level: The bacteria require oxygen to grow because their methods of energy production and respiration depend on the transfer of electrons to oxygen, which is the final electron acceptor in the electron transport reaction. But, some obligate anaerobs use fermentation or use anaerobic respiration in absence of oxygen.

4) Chloramphenicol: It is a bacteriostatic by inhibiting protein synthesis. It prevents protein chain elongation by inhibiting the peptidyl transferase activity of the bacterial ribosome. It is a broad spectrum antibiotic.