Upload
kiran-kumar
View
215
Download
0
Embed Size (px)
Citation preview
8/9/2019 3. Prokarytotic Growth and Nutrition
1/27
Lecture 3
Prokaryotic Growth and Nutrition
8/9/2019 3. Prokarytotic Growth and Nutrition
2/27
Growth of Bacterial Cultures
Bacteria reproduce by binary fission
8/9/2019 3. Prokarytotic Growth and Nutrition
3/27
Generation Time Generation time= time required for a cell to
divide
Most bacteria have a generation time of 1-3
hours
If binary fission continues unchecked an
enormous number of cells will be produced
8/9/2019 3. Prokarytotic Growth and Nutrition
4/27
8/9/2019 3. Prokarytotic Growth and Nutrition
5/27
Phases of growth
8/9/2019 3. Prokarytotic Growth and Nutrition
6/27
8/9/2019 3. Prokarytotic Growth and Nutrition
7/27
Requirements for Growth
8/9/2019 3. Prokarytotic Growth and Nutrition
8/27
Physical Requirements Temperature
pH
Osmotic Pressure
8/9/2019 3. Prokarytotic Growth and Nutrition
9/27
Temperature Psychrophiles- below 15C
Mesophiles- 10C- 45C
Thermophiles- 40C- 70C
Hyperthermophiles- above 80C
8/9/2019 3. Prokarytotic Growth and Nutrition
10/27
8/9/2019 3. Prokarytotic Growth and Nutrition
11/27
8/9/2019 3. Prokarytotic Growth and Nutrition
12/27
pH Optimal pH for growth
Acidophiles- acid-tolerant
8/9/2019 3. Prokarytotic Growth and Nutrition
13/27
Osmotic Pressure
Osmotic pressure- can kill cells
Extreme halophiles- require high salt
concentration
Facultative halophiles- do not require high
salt, but can grow at high salt
concentrations
8/9/2019 3. Prokarytotic Growth and Nutrition
14/27
Chemical Requirements
Carbon
Energy
Nitrogen, Sulfur, Phosphorus
Oxygen
Organic Growth Factors
8/9/2019 3. Prokarytotic Growth and Nutrition
15/27
Carbon Source Heterotrophs
Autotrophs
8/9/2019 3. Prokarytotic Growth and Nutrition
16/27
Energy Source
Chemoorganotrophs
Chemolithotrophs
Photoautotrophs
Photoheterotrophs
8/9/2019 3. Prokarytotic Growth and Nutrition
17/27
Nitrogen, Sulfur, Phosphorus Nitrogen used to synthesize amino acids
Sulfurneeded for some amino acids, and
some vitamins
Phosphorus essential for DNA and ATP
synthesis
8/9/2019 3. Prokarytotic Growth and Nutrition
18/27
Ox
ygen Obligate Aerobes- require oxygen to grow
Obligate Anaerobes- cannot tolerate oxygen
Facultative Anaerobes- can grow with orwithout oxygen
Microaerophiles- need concentration of
oxygen below what you find in atmosphere Aerotolerant- indifferent to presence of
oxygen
8/9/2019 3. Prokarytotic Growth and Nutrition
19/27
8/9/2019 3. Prokarytotic Growth and Nutrition
20/27
Organic Growth Factors Essential organic compounds an organism is
unable to synthesize
8/9/2019 3. Prokarytotic Growth and Nutrition
21/27
Media Complex media- may not know what
organism you are growing or what a
particular organisms needs
Defined Media- specific chemical
composition is known
8/9/2019 3. Prokarytotic Growth and Nutrition
22/27
Media Selective Media- allows certain bacteria to
grow but will inhibit others from growing
Differential Media- contains substances that
cause some bacteria to look different then
others
8/9/2019 3. Prokarytotic Growth and Nutrition
23/27
Quantification of Bacteria
8/9/2019 3. Prokarytotic Growth and Nutrition
24/27
Microscopic Counts: sample diluted,
counted with microscope
Most Probable Number: # of bacteria
determined based on comparison of some
growth parameter to statistical probability
8/9/2019 3. Prokarytotic Growth and Nutrition
25/27
8/9/2019 3. Prokarytotic Growth and Nutrition
26/27
8/9/2019 3. Prokarytotic Growth and Nutrition
27/27
Figure 6.20 - Overview (1 of 3)