1. بسم ا الرحمن الرحيم
GROWTH AND NUTRITION
OF BACTERIA
Prof. Khalifa Sifaw Ghenghesh
Dept. of Medical Microbiology,
Faculty of Medicine, Tripoli University
Tripoli - Libya
2. Growth: An Orderly Increase in All components of an Organism
– Multiplication >> Binary Fission.
Measurement of Growth:
– Increase in Numbers
– Increase in Mass
Batch Culture:
– Growth Curve:
A Total Count.
A Viable Count.
1. Lag Phase
2. Log (logarithmic) Phase
3. Stationary Phase
4. Death Phase
3. GROUTH REQUIREMENTS AND BACTERIAL NUTRITION:
Suitable Nutrients Must Be Supplied
Physical Conditions Must Be as Near as Possible for
the Organism Under Consideration
BACTERIAL METABOLISM:
Bacteria Require:
An Energy Source
A Carbon Source
A Nitrogen Source
Other Inorganic Salts and Accessory Growth Factors.
1. Photo-autotrophs:
2. Chemo- autotrophs
3. Heterotrophs:
4. OXYGEN REQUIREMENTS AND METABOLISM:
1. Obligate Aerobes
2. Obligate Ananerobes
3. Facultative Anaerobes
4. Microaerophilic Bacteria.
MEDIA FOR BACTERIAL GROWTH:
1. General Laboratory Media:
– Peptone >> Amino acids
– Growth factors and inoorganic salts
– NaCl
1. Synthetic Media
2. Special Media:
– Selective media
– Indicator media
– Enrichment media
5. PHYSICAL CONDITIONS
REQUIRED FOR GROWTH
1. Influence of Oxygen and CO:
2. Influence Temperature:
– On Growth:
Mesophilic bacteria
Psychrophilic bacteria
Thermophilic bacteria
– On Viability:
1. Influence of Moisture and Desiccation:
6. 4. Influence of Hydrogen Ion Concentration
(pH):
5. Influence of Light and other radiations:
6. Influence of Osmotic Pressure:
7. Influence of Mechanical and Sonic Stresses:
7. 4. Influence of Hydrogen Ion Concentration
(pH):
5. Influence of Light and other radiations:
6. Influence of Osmotic Pressure:
7. Influence of Mechanical and Sonic Stresses: