View
221
Download
0
Category
Preview:
Citation preview
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
1/32
&Microbial growth
Factors affectinggrowth
.Arunec ture r in
,icrobiology,h ia ga ra ja r c ol le ge
Madurai
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
2/32
Growth In Physical term
Increase in size or number of Individual cell
Many factorsDetermine the cell to divide or grow
Physical factorsEnvironmentalconditions,
Temperature, O2,Pressure etc.
Chemical Factors -pH, nutrient etc.
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
3/32
rowth in Prokaryotes Various biochemical & physical events
From time it derived from parental cell
Until it divides in to two daughter cells
This period of time is called
Bacterial cell cycle
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
4/32
acterial cell cycle Characterized by Number of event
qGrowth Coordinated synthesis of macromolecules as well as cellularcomponents
qSeptum formationqDivision
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
5/32
Binary fission
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
6/32
Binary fission
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
7/32
rowth Ph ases
Batch culture Continuous culture
Cells grown in batch nutrient Continuous nutrient environment
environment
Microbial populationsMicrobial populations
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
8/32
rowth cu rve
Cell have various Growth phases
Growth curve
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
9/32
hases of growth
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
10/32
Phases of growth
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
11/32
Lag phase
Require some time to adjust to their newenvironment
Lag Refers lag in cell division
During Lag
1. in size, Produce enzymes to metabolize the nutrients. 2. Synthesize RNA and Protein.
DNA remain constant
Following Inoculation
Increase
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
12/32
Lag Phase
Is related to
Physiological and genetic state of cell at the time ofinoculation.
Cells Nutritionally starved long Lag phase
If from nutritionally rich short lag phase
engt h of La g phase
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
13/32
( )Log phase Exponential phase
Phase at which cell division is maintained at a constant andmaximum rate.
e.g., InE.coli Nutrient rich
medium
e.g., InE.coli Less nutrient rich
medium
Take 30 min to divide
Take 60 min to divide
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
14/32
Log phase
Doubling time Remain constant in log phase
Log Phase said to bebalanced growth
In Log Phase Cellpopulation doubles .So also DNA , RNA &Protein
In Batch Culture:
No nutrient enter
No waste product removedAt one time:
Reach a point rate of growth slows downDue to the factors such as : Over crowding, Nutrietion depletion , pH etcEnd of the Log Phase : Trophophase Primary metabolites produced
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
15/32
Stationary phase
Number of cellsConstant. Called as Unbalancedgrowth
components & macromolecules Synthesized at different rate
Some cells Divide and others die
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
16/32
Stationary phase
Cells which are alive produce 2ndary metabolites and wastes
Idiophase
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
17/32
eath or Decl in e phas e Death of the cell increased
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
18/32
Continuous culture
In batch culture it can not control the factors (Nutrient supply & waste removal)which
decrease the growth rate.
To Overcome this problem
Continuous culture system can be used.
q Primary purpose of continuous culture
To maintain cell population at constant rate
The devised used Chemo stat & turbidostat
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
19/32
Factors affecting growth
In addition to Chemical needs also affected by physical nature ofenvironment
Environmental factors Temperature , pH, Osmotic pressure , radiation
Influence the growth of the particular organism
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
20/32
Temperature
Growth Influenced by Enzymaticreactions TemperaturePlays Imp role
Temperature Max Growth Optimum growth temperature (*)
Above (*) Enzyme get denatured
Below (*) Enzyme get inactivated
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
21/32
Based on Optimum growth temperature
Psychrophiles
Mesophiles
Thermopiles
Hyper thermopiles
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
22/32
Psychrophiles
Grow Between 0 to 20c
Found Antarctic, cold soil, Stream, Ocean water, Rivers, Lakemud.
Role Biodegradation in cold water lake, refrigerated foods.
Ribosome Unstable above 20
Psychrophiles protected from cold unsaturated fatty acids
High Temperature Disrupt fatty acid Cell content leak
Lysis
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
23/32
Thermophiles
Grow Between 40C to 80C.Some grow even in 90C to 100C.
Some G+ / G-Bacilli, Cyanobacteria, Photosynthetic bacteria Thermophiles
- Present in hot springs
- Have normal cell components as is mesophiles
-
With standHigh temperature Presence ofpolar amino acids in interior of cell
Cell membrane componentsMore branched,longer and saturated fatty acid
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
24/32
Mesophiles
Most Microbes Mesophiles
Temp Range - Between 25 to 40c
Optimum Temp - 37c
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
25/32
Osmotic pressure
Food with 12% salt No Microbes grow
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
26/32
Hydrostatic pressure
In every 10meter
One atm. P increase
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
27/32
Hydrostatic pressure
Barobiology Study the effect of Pressure on Living things.
Barophiles/ Baro tolerant Live in High pressure
Non Barophiles Have gas vacuoles
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
28/32
Hydrogen ion concentration
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
29/32
Hydrogen ion concentration
Buffer system used
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
30/32
Hydrogen ion concentration
Types
Acidophiles
Basophiles
Neutrophiles
dont have peptidoglycon layer
Have Polyhexagonal array of protein forstability
Fungi- Grow in pH 5
Bacteria - Grow in pH 7
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
31/32
Electromagnetic radiation
Microbes grow - Visible Range
8/14/2019 Arun- Microbial Growth & Factors Affecting Growth
32/32
Electromagnetic radiation
Phototrophs
Use light energy
Recommended