The growth kinetics of E.coli is studied using the shake flask fermentation was studied by plotti... more The growth kinetics of E.coli is studied using the shake flask fermentation was studied by plotting the graph of real absorbance optical density versus time. The Terrific Broth is prepared by autoclaving the media at 121°C for 20 minutes. The E.coli inoculum was grown for 5 hours at 300 rpm. 10% of the inoculum which is 15mL is added into sterilized media of 150 mL then incubated in thermostat rotary shaker at required rotational speed and temperature for 16 hours. An amount of sample was transferred into the sampling tube every one hour interval. The absorbance optical density is measured using the spectrophotometer. The lag phase occur during the 0 th hour until the 1 st hour, where the bacteria began to adapt themselves to the growth conditions. After going through lag phase, the bacteria undergo the exponential phase which started at the 1 st hour until the 7 th hours. The value of the maximum growth rate (max) of the cell from the slope of the graph ln X/X0 versus time, where max is at 0.0571 hr-1. The appearance of the 2nd exponential phase was due to the presence of foreign microorganisms from the environment where it is believed to have consumed the E.Coli as a source of nutrients. The death phase occurred at time t = 11 to t =14 where the sudden death of the microorganism was because insufficient source of nutrients that has been fully consumed. The net for the respective phase are net, lag phase = 0.0460 h-1 , net, exponential phase = max = 0.0571 hr-1 , net, stationary phase = 0.0000 hr-1 , net, death phase = 0.0000 hr-1 .
Enzymes are biological catalysts, in which it is specific to only one type of reaction and to one... more Enzymes are biological catalysts, in which it is specific to only one type of reaction and to one small group of reactants called substrates. Enzymes take part in the reaction where the catalyst provides an alternative reaction pathway. The effects of temperature, pH and substrate concentration on the enzymatic activity were studied. The double reciprocal method was used in order to find Michaelis constant, Km. Based from the graph of effect of substrate concentration, it shows the bell shaped curve pattern rather than straight linearly line as in the standard curve graph and the ideal condition of the amylase enzyme is obtained at substrate concentration, [S] = 1.5%, in which the enzyme shows the maximum rate of activity at this concentration. For the effect of temperature, the optimum temperature for the enzyme obtained from the graph is at 50℃, which the enzyme activity is at 2.421 x 10-7 mol/min. Lastly, for the effect of pH, the graph showed that the enzyme activity increased from pH 5 until pH 6 and decreased until pH 7 and later increased again until pH 9. Therefore, pH 6 is the most optimum pH for the enzyme activity.
The growth kinetics of E.coli is studied using the shake flask fermentation was studied by plotti... more The growth kinetics of E.coli is studied using the shake flask fermentation was studied by plotting the graph of real absorbance optical density versus time. The Terrific Broth is prepared by autoclaving the media at 121°C for 20 minutes. The E.coli inoculum was grown for 5 hours at 300 rpm. 10% of the inoculum which is 15mL is added into sterilized media of 150 mL then incubated in thermostat rotary shaker at required rotational speed and temperature for 16 hours. An amount of sample was transferred into the sampling tube every one hour interval. The absorbance optical density is measured using the spectrophotometer. The lag phase occur during the 0 th hour until the 1 st hour, where the bacteria began to adapt themselves to the growth conditions. After going through lag phase, the bacteria undergo the exponential phase which started at the 1 st hour until the 7 th hours. The value of the maximum growth rate (max) of the cell from the slope of the graph ln X/X0 versus time, where max is at 0.0571 hr-1. The appearance of the 2nd exponential phase was due to the presence of foreign microorganisms from the environment where it is believed to have consumed the E.Coli as a source of nutrients. The death phase occurred at time t = 11 to t =14 where the sudden death of the microorganism was because insufficient source of nutrients that has been fully consumed. The net for the respective phase are net, lag phase = 0.0460 h-1 , net, exponential phase = max = 0.0571 hr-1 , net, stationary phase = 0.0000 hr-1 , net, death phase = 0.0000 hr-1 .
Enzymes are biological catalysts, in which it is specific to only one type of reaction and to one... more Enzymes are biological catalysts, in which it is specific to only one type of reaction and to one small group of reactants called substrates. Enzymes take part in the reaction where the catalyst provides an alternative reaction pathway. The effects of temperature, pH and substrate concentration on the enzymatic activity were studied. The double reciprocal method was used in order to find Michaelis constant, Km. Based from the graph of effect of substrate concentration, it shows the bell shaped curve pattern rather than straight linearly line as in the standard curve graph and the ideal condition of the amylase enzyme is obtained at substrate concentration, [S] = 1.5%, in which the enzyme shows the maximum rate of activity at this concentration. For the effect of temperature, the optimum temperature for the enzyme obtained from the graph is at 50℃, which the enzyme activity is at 2.421 x 10-7 mol/min. Lastly, for the effect of pH, the graph showed that the enzyme activity increased from pH 5 until pH 6 and decreased until pH 7 and later increased again until pH 9. Therefore, pH 6 is the most optimum pH for the enzyme activity.
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