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From 2013hs.igem.org

Contents 1 Issues: 1.1 The Need for Renewable Energy 1.2 Biofuels are Unsustainable 1.3 The Negatives of Corn Ethanol

Issues:

The Need for Renewable Energy

The major source of modern energy is derived from the burning of fossil fuels. Fossil fuels are organic material that has been heated and pressurized for over time and are used as fuel. The issue with fossil fuels is the negative impacts to the environment. Our biosphere goes through a carbon cycle transferring carbon through many forms across the planet. Fossil fuels however are carbon that has been stored for ages and no longer belongs in our modern cycle. Thus when this fuel is burned, an overabundance of greenhouse gases are released into the atmosphere. Greenhouse gases trap solar radiation in the atmosphere which is a contributing factor to the overcoming problem of global climate change.

Biofuels are Unsustainable

A renewable source of energy that has the potential to replace fossil fuels is biofuels. Biofuels are a produced from biomass, or living things. While fossil fuels are from once living things, they are from organisms that have been dead for millions of years, while biofuels are from recently dead organisms. The biofuel of focus, which has been used most frequently, is corn ethanol. Corn ethanol, as its name states, is produced from the biomass of crop corn. Corn ethanol is a cleaner fuel and does not disrupt the life cycle as its carbon emissions coincide with the carbon cycle. The production of corn ethanol is the problem. Corn ethanol is produced by extracting starch from corn plants. The starch is then broken down by enzymes into glucose. The glucose is the fermented by yeast into ethanol, and that is the basic rundown of the production. The problem lies within the source of the glucose, from corn, which is also a food crop. Thus competition for crops for food and crops for fuel is formed. Competing against food when there also exists the global food shortage process is not wise and many negative side effects exist.

The Negatives of Corn Ethanol

Corn competition: As corn is split between biofuels and crop food, the supply for either is lowered, while the demand for food remains the same. This result in food prices going up for corn, which is a standard in many other products, so prices go up across the board.

Damages developing economies: Many farmers in developing nations notice the increase in demand for the yellow corn used in biofuels to the white corn they used for local food production, causing many of them to switch. This decreases the supply of white corn, which is used for many regional commodity foods such as for tortillas in Mexico, which increases the price of said products.

Deforestation: As demand for corn ethanol increases in the United States , more and more plantations switch over from farming soybean to corn. Thus other countries are left with the burden of meeting soybean demands and planting there. For example soybean plantations in Brazil have gone from one third of the amount the U.S. had to more than triple of what we now have. This leads to severe deforestation of the rainforests in Brazil to compensate for the land needed to farm.

Agricultural impacts: Increases in corn plantations also increase pesticide usage which is harmful to health. Nitrogen-run off, which contaminates water wells and increase in dust pollution in the air which can also be harmful to health especially in those with asthma.

Inefficiency: To power an automobile for a year, 11 acres of corn are required, which is equivalent to feeding 7 people.

While the production of biofuels does pose many problems, the benefits are very positive. Thus our intents are to produce ethanol without using corn. In 2011, the Nevada iGEM team created an ethanol generator that converted glucose into ethanol within an E. coli’s metabolism. The glucose was provided from cyanobacteria so it was a symbiosis of bacteria instead of corn. We would like to move forward by removing the media aspect of growing the cells and making E. coli solar powered to place it a solar panel type construct. More on this in the following pages!