Growth Curve of Serratia marcescens
Experiment 9: Growth curve of Serratia marcescens
Abstract
Bacteria grows by binary fission. The aim of this experiment is to follow the growth of Serratia marcescens in nutrient broth at 37oCby recording the changes in turbidity (cloudiness) by measuring the absorbance of visible light (600 nm) and also to prove that there is an increase in the cell number and not just in mass during the growth. In the experiment we measure the full growth curve of Serratia marcescens by measuring the absorbance at 600nm at every 10 mins. I also determined the viable count at the start and the end of the exponential phase of growth. Using the growth curve I calculated the growth curve and it was 1.2. Using this I found the doubling time which was 34s.
Introduction
Bacteria grows by binary fission. One bacteria becomes two, two bacteria becomes four bacteria and it so goes on. A lot of changes occur in the bacterial cell during growth and due to this reason it is difficult to measure growth quantitatively. Growth is therefore usually measure by changing one or two easily measure parameters which will ignore the complicated cellular change. Therefore different type of analysis may yield different results and the measure of cell growth is only a crude method.
We can measure the bacteria growth by either monitoring the changes in the absorbance reading ( the culture becomes more cloudy as the numbers increase and the cells grow in size ) and to prove that there is an increase in cell number and not just the increase in mass during growth we determine the viable count at the start and end of the period where there is most active growth or we can measure the chemical or biochemical property of the cell (e.g.: protein concentration)
In this experiment we measure the absorbance reading and plot a growth curve.
Fig 1: Bacterial growth curve showing phases of growth Acceleration phase
During batch culture, a
Abstract
Bacteria grows by binary fission. The aim of this experiment is to follow the growth of Serratia marcescens in nutrient broth at 37oCby recording the changes in turbidity (cloudiness) by measuring the absorbance of visible light (600 nm) and also to prove that there is an increase in the cell number and not just in mass during the growth. In the experiment we measure the full growth curve of Serratia marcescens by measuring the absorbance at 600nm at every 10 mins. I also determined the viable count at the start and the end of the exponential phase of growth. Using the growth curve I calculated the growth curve and it was 1.2. Using this I found the doubling time which was 34s.
Introduction
Bacteria grows by binary fission. One bacteria becomes two, two bacteria becomes four bacteria and it so goes on. A lot of changes occur in the bacterial cell during growth and due to this reason it is difficult to measure growth quantitatively. Growth is therefore usually measure by changing one or two easily measure parameters which will ignore the complicated cellular change. Therefore different type of analysis may yield different results and the measure of cell growth is only a crude method.
We can measure the bacteria growth by either monitoring the changes in the absorbance reading ( the culture becomes more cloudy as the numbers increase and the cells grow in size ) and to prove that there is an increase in cell number and not just the increase in mass during growth we determine the viable count at the start and end of the period where there is most active growth or we can measure the chemical or biochemical property of the cell (e.g.: protein concentration)
In this experiment we measure the absorbance reading and plot a growth curve.
Fig 1: Bacterial growth curve showing phases of growth Acceleration phase
During batch culture, a