This document discusses the bacterial growth curve, which graphs the change in a bacterial population over time in a culture. It has four phases: 1) Lag phase where bacteria adapt to their environment, 2) Log or exponential phase where bacteria multiply at their maximum rate, 3) Stationary phase where growth balances with death due to nutrient depletion, and 4) Decline phase where bacterial death exceeds growth and the population decreases. The growth curve is useful for studying bacterial ecology, producing antibiotics, and biodegrading toxins.

1. BACTERIAL GROWTHCURVE
Represented by WASIM AKRAM
BSC NURSING
ADWIKA INSTITUTE OF NURSING

2. CONTENTS
 INTRODUCTION
 DEFINITION
 PURPOSES
 PHASES OF GROWTH CURVE
1. LAG PHASE
2. LOG PHASE
3. STATIONARY PHASE
4. DECLINE / DEATH PHASE
 CONCLUSION

3. INTRODUCTION
 THE GROWTH OF BACTERIAL POPULATION CAN
BE REPRESENTED ON A GROWTH CURVE .
 A CURVE ON A GRAPH THAT SHOWS THE
CHANGES IN SIZE OF A BACTERIAL POPULATION
OVER TIME IN A CULTURE .

4. DEFINITION
BACTERIAL GROWTH CURVE IS A GRAPHICAL
REPRESENTATION OF HOW A PARTICULAR
QUANTITY OF BACTERIA INCREASES OVER A TIME
IN A CULTURE MEDIUM .

5. PURPOSES
1. TO PRODUCE OF ANTIBIOTICS .
2. ECOLOGICAL STUDIES – ENHANCE PLANT
GROWTH .
3. BIODEGRADATION OF TOXIC ORGANICS .

6. PHASESOF
GROWTH
CURVE
 THERE ARE FOUR PHASES OF BACTERIAL
GROWTH CURVE -
1. LAG PHASE / ADAPTATION PHASES
2. LOG PHASE / EXPONENTIAL PHASE
3. STATIONARY PHASE
4. DECLINE / DEATH PHASE

7. DIAGRAMOF
BACTERIAL
GROWTHCURVE

8. 1.LAGPHASE
 IT IS THE ADAPTATION PHASE ; IN THIS PHASE ,
THERE IS AN INCREASE IN CELL SIZE BUT IT
DOES NOT MULTIPLIES .
 THE BACTERIA WERE ADJUSTING TO THEIR
NEW ENVIRONMENT .
 THE LENGTH OF THIS PHASE MAY VARIES
BASED ON THE OXYGEN AVAILABILITY, PH OF
THE ENVIRONMENT, NUTRIENTS AVAILABILITY ,
THE TEMPERATURE OF THE ENVIRONMENT .
 IN THIS PHASE , THE METABOLIC ACTIVITY
WILL BE GET VIGOROUS ; SYNTHESIS OF RNA ,
ENZYMES etc. WILL BE OCCURRED .

9. 2.LOGPHASE
 IT IS ALSO KNOWN AS EXPONENTIAL PHASE .
 THE BACTERIAL CELLS MULTIPLY AT A
MAXIMUM RATE .
 IT IS THE PHASE WHERE THE GROWTH IS
BALANCED AND DOUBLING POPULATION .
 EQUATION :
• N – THE FINAL CELL CONCENTRATION
• N ° - THE INITIAL CELL
CONCENTRATION
• n – NUMBER OF GENERATION THAT
OCCURRED BETWEEN THE
SPECIFIED
PERIOD OF TIME .

10. 3.STATIONARY
PHASE
 IN THIS PHASE , DUE TO EXHUSTION OF
NUTRIENTS AND ACCUMULATION OF TOXIC
PRODUCTS , THE BACTERIAL CELL DEATH WILL
GET START AND THE GROWTH OF BACTERIA
CEASED .
 THE COUNT REMAINS STATIONARY DUE TO
BALANCE BETWEEN MULTIPLICATION AND
CELL DEATH RATE .

11. 4.DECLINE/
DEATHPHASE
 IN THIS PHASE , PROGRESSIVE CELL DEATH
WILL OCCUR AND THE LIVING BACTERIA USE
THE BREAKDOWN PRODUCTS OF DEATH
BACTERIA AS NUTRIENTS .

12. CONCLUSION
BACTERIAARE THE PROKARYOTIC ORGANISMS .
EACH AND EVERY ORGANISMS HAS THEIR
CERTAIN LIFE SPAN AND PASSES THROUGH BIRTH
, GROWTH AND DEVELOPMENT , AND FINALLY
LEADS TO DEATH . HERE WE HAVE DISCUSSED
ABOUT BACTERIAL GROWTH CURVE . IN THIS
GRAPHICAL PRESENTATION WE HAVE DISCUSSED
FOUR PHASES : LAG PHASE , LOG PHASE ,
STATIONARY PHASE AND DEATH OR DECLINE
PHASE .