Bacterial Growth Curve

Bacterial growth curve is a graphical presentation of how bacterial population increases in a particular medium at a certain time .

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

2. CONTENTS INTRODUCTION DEFINITION PURPOSES PHASES OF GROWTH CURVE LAG PHASE LOG PHASE STATIONARY PHASE 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 TO PRODUCE OF ANTIBIOTICS . ECOLOGICAL STUDIES – ENHANCE PLANT GROWTH . BIODEGRADATION OF TOXIC ORGANICS .

6. PHASES OF GROWTH CURVE THERE ARE FOUR PHASES OF BACTERIAL GROWTH CURVE - LAG PHASE / ADAPTATION PHASES LOG PHASE / EXPONENTIAL PHASE STATIONARY PHASE DECLINE / DEATH PHASE

7. DIAGRAM OF BACTERIAL GROWTH CURVE

8. 1. LAG PHASE 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. LOG PHASE 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 / DEATH PHASE IN THIS PHASE , PROGRESSIVE CELL DEATH WILL OCCUR AND THE LIVING BACTERIA USE THE BREAKDOWN PRODUCTS OF DEATH BACTERIA AS NUTRIENTS .

12. CONCLUSION BACTERIA ARE 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 .