Nowadays, global temperatures have increased by 1.1 degrees Celsius since the late 1800’s, one of the main causes of this is the massive emission of greenhouse gases. Our lab decided to tackle the problem of global warming by focussing on how we can maximize biofuels more efficient. Algae-based biofuel can reduce greenhouse gas emissions by 60% compared to petroleum based fuels.The aim behind our project is to create a co-culture between the bacteria, Chlorella minutissima and Escherichia coli to maximize the lipid production in C. minutissima. In order to do this we will be altering the C. Minutissima and E. Coli with the IAA plant growth hormone and culturing the two bacteria together in a tube. The increased lipid production and optical density would be what we are looking for. The co-culture can then be sent to a more advanced laboratory to produce biofuels from these lipids. The solution we are hoping to gain is a more sustainable way of producing fuels compared to the alternative of burning fossil fuels.

1. Why Choose This Project

The production and use of fossil fuels have negatively impacted the environment in numerous ways. It has been proven that fossil fuels increase the release of carbon emissions into the atmosphere, which scientists have claimed have contributed to global warming. Biofuels serve as an alternative to fossil fuels and a much more renewable energy source compared to fossil fuels. Microalgae are important subjects in economically producing biofuels while consuming harmful environmental agents, such as carbon dioxide and wastewater (Li, et all, 2008). However, the main disadvantage to using microalgae is the low biomass concentration to produce biofuels to sustain a country compared to petroleum-based fuels (Pienkos, Laurens, Aden). Additional studies have been performed to study variables contributing to microalgae growth. According to a study performed by Higgins and VanderGheynst in 2014, mixotrophic cultures of the algae Chlorella minutissima in wastewater, simulated using E. coli, can improve microalgae biomass and lipid production.

2. Our Design Content

Our goal is to create a synthetic biology system that will increase lipid production from microalgae to serve as an intermediate in chemical reactions needed to create biofuels. Specifically, we will create a co-culture between C. minutissima, microalgae, and E. coli to increase the cell density of C. minutissima. E. coli will be modified with the IAA pathway, which we propose will increase C. minutissima’s growth rate. C. minutissima will be modified with genes encoding for enzymes known as Glycerol-3-phosphate acyltransferase (GPAT), Lysophosphatidic acid acyltransferase (LPAAT), and Diglyceride acyltransferase (DGAT) to increase lipid production. We hypothesize that these factors will create a dense algae population with high lipid content, providing ideal parameters for biofuel production. We will use synthetic biology techniques to test our hypothesis. We designed gene sequences for increased lipid production, specifically triacylglycerols, in C. minutissima. We also designed gene sequences for production of IAA, a plant growth hormone, in E. coli. We will transform these genes into C. minutissima and E. coli respectively. In a co-culture, E. coli will provide C. minutissima with carbon dioxide, IAA, and other molecules to increase growth rate and cell density. Our hypothesis states that by co-culturing the two synthetic biology between the two organisms would lead to increased lipid production in the C. minutissima. This final product can later on be sent to industries that can refine the organism to produce biofuels.

3. Benefits To Society

With the continuous human exploitation, the depletion of fossil energy is inevitable, most of the fossil energy will be mined out this century. On the other hand, in the process of fossil energy use, a large amount of greenhouse gas carbon dioxide will be added, and some polluting smoke will be produced, thus threatening the global ecology. Biofuels serve as an alternative to fossil fuels and a much more renewable energy source compared to fossil fuels. Biofuels can both ease energy demand and be greener than fossil fuels. Microalgae are important subjects in economically producing biofuels while consuming harmful environmental agents, such as carbon dioxide and wastewater. Our project will create a synthetic biology system that will increase lipid production from microalgae to serve as an intermediate in chemical reactions needed to create biofuels, in order to find new green fuel, and promote the development of environmental protection.