Team:UConn/Description

UConn IGEM 2017 - Interlab Study

Biofuels: Why are they important?


Over-utilization of fossil fuels as primary energy sources is a major contributor to anthropogenic climate change. Over the next 50 years, the effects of climate change will become more acute, while depletion of fossil fuel reserves may contribute to an energy shortage. Continued development of alternative fuel sources that are both renewable and carbon-neutral (i.e. do not net-release greenhouse gases) is imperative to provide economically viable methods to combat climate change and decrease reliance on nonrenewable fuels.

Biofuels are fuels produced from recent biological processes, rather than from prehistoric ones. As such, production of biofuels is renewable and nearly carbon-neutral (nearly all carbon released from burning of biofuel is the result of recent carbon fixation - only processing requires input of energy). While some common feedstocks (e.g. corn, trees, sugarcane) can be effectively utilized as biofuels, such processing requires disproportionate amounts of land and reduces the crops’ availability as food stock. Algal biofuel feedstocks, which do not overlap with food supplies, have recently gained much attention due to their high productivity in a given area. However, processing lipids from algae poses a technical challenge and current extraction methods cause death to the algae. This can complicate maintenance of viable algal feedstocks.



How did we aim to help this field?


The goal of our project was to genetically modify the green algae Nannochloropsis oceanica with the goal of bringing down the cost of extracting its lipids for processing into biofuels in an industry setting. Biofuels present a cleaner future for the world and algae are the key to making the industry competitive with fossil fuels. We chose Nannochloropsis as it is a resilient marine based algae that has a high oil content. These traits make it ideal for large scale cultivation and processing for biofuels. Additionally the strain we used responds well to transformation techniques, lacks a restriction system and has efficient homologous recombination. Lastly we observed that other iGEM projects had struggled to transform more common and better studied algae in similar projects, and so we decided to opt for a less studied but better suited species of algae.

In order to genetically modify Nannochloropsis oceanica with an aim of improving its lipid content and make the lipids easier to extract, we identified the genes responsible for key enzymes involed in lipid production and usage. We set out to alter the regulation of these gene targets to make the process more efficient. As for making the lipids easier to extract, we identified a lipid transporter present in the plant Arabidopsis thaliana, and attempted to express it in Nannochloropsis oceanica to facilitate extracellular lipid excretion. If successful, algal lipid content would be increased and made accessible extracellularly, eliminating the need for killing and reculturing algal feedstocks.