Project Description

Overview

This year, our team is working on biofuel production using E. coli. In the US, most biofuel production comes from either corn or sugar cane to produce ethanol. Both of these crops require arable land and pull resources from the food supply. Algae is another option, but it requires land area for growing ponds. E. coli, on the other hand, can be grown in fermenters in a factory and do not affect the food supply or remove arable land from other productive use. E. coli naturally produces several alcohols that can be used as biofuels, including isopropanol, isobutanol, ethanol, and sec-butanol. Unfortunately, E. coli also has pathways that break down these alcohols when the concentration increases to prevent toxic levels from occurring. The combination of increasing the natural resistance to these alcohols as well as up-regulating the production of one or more of these alcohols could make this production methods commercially viable.

E. coli

Escherichia coli (E. coli) bacteria normally live in the intestines of people and animals. Most E. coli are harmless and actually are an important part of a healthy human intestinal tract. However, some E. coli are pathogenic, meaning they can cause illness, either diarrhea or illness outside of the intestinal tract. The types of E. coli that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or persons.

E. coli consists of a diverse group of bacteria. Pathogenic E. coli strains are categorized into pathotypes. Six pathotypes are associated with diarrhea and collectively are referred to as diarrheagenic E. coli.

Shiga toxin-producing E. coli (STEC)—STEC may also be referred to as Verocytotoxin-producing E. coli (VTEC) or enterohemorrhagic E. coli (EHEC). This pathotype is the one most commonly heard about in the news in association with foodborne outbreaks.
Enterotoxigenic E. coli (ETEC)
Enteropathogenic E. coli (EPEC)
Enteroaggregative E. coli (EAEC)
Enteroinvasive E. coli (EIEC)
Diffusely adherent E. coli (DAEC)

Results

Figure____shows the survival percentage of E.coli under different concentrations of Ethanol.

Figure____shows the survival percentage of E.coli under different concentrations of Isobutanol.

Figure____shows the survival percentage of E.coli under different concentrations of Isopropanol.

Figure____shows the survival percentage of E.coli under different concentrations of 2-butanol.

This is our final data chart:

In the graph, the X-axis represents the amount of Isobutanol in the alcohol. The Y-axis shows the survival rate of E-coli when there is Isobutanol occurring––how well E-coli resists Isobutanol. The solid circle with a line goes through it represents the control––E-coli only. The solid square represents the E-coli with gene GlmY inside. Scatter chart is made according to the E-coli’s survival rate with different amount of Isobutanol inside the alcohol. Two solid black smooth decreasing curves are created based on the scatters’ tendency. The beginning of both curve is at (0, 100), which means there is no Isobutanol in the alcohol and the survival rate of the E-coli is 100%. One of the curve is the line of Control. The curve of control indicates how E-coli resists in Isobutanol when there is no genetic energy added. The other curve is made after we put gene GlmY––genetic energy––into E-coli plasmid. We can compare two curve and discover that the curve of GlmY is above the control curve. That mean the survival rate of E-coli is higher with GlmY inside. It basically means it is easier for E-coli to resist Isobutanol with GlmY. We can see when x=60, there is 60 ml Isobutanol inside the alcohol, the survival rate of E-coli according to the control curve is 12.4%; the survival rate of GlmY curve is 24.8%, which is almost twice as the control curve. Therefore, we can say it is easier for E-coli to resist Isobutanol with GlmY inside it.

Conclusion

Future Development

References

General Information. (2015, November 06). Retrieved October 20, 2017, from https://www.cdc.gov/ecoli/general/index.html