Escherichia Coli Essay

The Figure 4.20 shows the profile growth of Escherichia coli type K-12 which was cultured in 20 g/L of glycerol treated with supplements from a carbon source under anaerobic condition and the medium supplemented with 10 g/L of trypton. About 10% working volume of inoculums were added to the medium for the profile growth process. The effects on growth curves of strains of Escherichia coli were investigated by measuring the concentration of succinic acid produced and its optical density by using HPLC and the spectrophotometer instrument or uv-vis. The optical density, which is measured using a transmission densitometer, is a representation of a material's light blocking ability. The results show that succinic acid production and the optical density
Conversely, the glycerol remaining decreased with time. The results for glycerol remaining are shown in figure 4.20. The succinic acid production at 6 hours was 4.2736 g/L and gradually increased with time. These results show that the bacteria Escherichia coli in the medium grew actively with time. After 72 hours of profile growth the succinic acid production was about 4.6846 g/L. Furthermore, it can be concluded that the bacteria Escherichia coli type K-12 can actively grow in the medium with supplements and treated glycerol producing glycerol residue and consequently can also produce succinic acid
Normally the optimal temperature for Escherichia coli growth is approximately 37 oC and the optimum pH range for growth is 6-7. However, the organism failed to grow at a temperature of 50 °C. The Escherichia coli can grow well and produce succinic acid at a temperature of 37 oC in a 72 hour fermentation process. Temperature effects the production of succinic acid by effecting the activities of the enzymes involved in the process. The activity of enzymes in medium fermentation is via the reverse TCA cycle. A temperature of 37 oC is the optimum temperature for enzyme