Lag phase no immediate increase in cell mumber. The cell is synthesizing new compoments AtP cofactor. ribosomes enzymes The lag phase varies in length with the condition of the microorganisms and the nature of the medium How to shorten the lag phase
Lag phase • no immediate increase in cell mumber. The cell is synthesizing new compoments. ATP, cofactor, ribosomes, enzymes. • The lag phase varies in length with the condition of the microorganisms and the nature of the medium. • How to shorten the lag phase?
Exponential phase/log phase Microorganisms are growing and dividing at the maximal rate possible The population is most uniform in terms of chemical and physiological properties Such culture: biochemical and physiological studies
Exponential phase/log phase • Microorganisms are growing and dividing at the maximal rate possible. • The population is most uniform in terms of chemical and physiological properties. • Such culture: biochemical and physiological studies
Stationary phase Balance between cell division and cell death Poplation growth ceases and the growth curve becomes horizontal Bacteria: 10 cells per ml Protozoan and algae 106 cells per ml Reasons:1. Nutrient limitation 2 The accumulation of toxic waste products 3. A critical population level is reached
Stationary phase • Balance between cell division and cell death. Poplation growth ceases and the growth curve becomes horizontal. Bacteria: 109 cells per ml; Protozoan and algae: 106 cells per ml. • Reasons: 1. Nutrient limitation 2. The accumulation of toxic waste products 3. A critical population level is reached