Difference between revisions of "Team:Macquarie Australia/Description"

Project Description

Our project has its focus on photosynthesis - the natural process where plants and algae convert sunlight into useable energy. By developing artificial photosynthesis in a biological system we can better harvest the unlimited supply of solar energy. The long-term goal is to engineer bacteria that can produce hydrogen gas on an industrial scale. This year the aim of our team is to engineer bacteria to manufacture chlorophyll - the primary molecule of photosynthesis. Chlorophyll harvests light and is involved in the excitation transfer of energy. Chlorophyll-a can be synthesised via a pathway from the protoporphyrin-IX molecule. By placing 13 genes into 4 biobrick vectors we can recreate the pathway in Escherichia coli.

Experimental Organism

Why did we choose Escherichia coli (E.coli) as a chassis? One reason is that E.coli is a well-categorised species with an abundance of literature and stocks world-wide.

Ideas Explored

The two different ideas that our project explores are the academic basis of photosynthesis and the potential applications. Academically we want to learn more about the photosystems that enable photosynthesis. However, we also want to investigate real-world applications to help the public engage with the topic.

What is new from last year?

We completed the Chlorophyll biosynthesis pathway within E. coli. A completely new aspect is the construction of Photosystem-II. We placed into biobricks 17 important Photosystem-II genes designed to function in 5 operons.

Project Background

The Looming Energy Crisis

The global population currently faces a looming energy crisis^1,2. Fossil fuels - the traditional sources of energy used to facilitate human civilisation - are dwindling in supply¹. Therefore, alternative energy sources must be discovered and developed in order to achieve future energy security.

Attempted Solutions

Renewable energy technologies which indirectly harness the power of the sun - such as wind and wave power - are currently utilised across the world in varying degrees^2,3. It is also increasingly popular to directly harness solar power by converting light energy to electrical energy in solar cells³. However, there are issues associated with the implementation of this technology such as the energy-expensive nature of solar cell and battery construction and maintenance.

Photosynthesis - Nature’s Answer to the Problem

It's well known that photosynthesis is nature's own way of converting light energy from the sun into chemical energy in the form of glucose. The goal of Macquarie University's 2015 iGEM team - the Solar Synthesisers - is to utilise the solar-harnessing powers of chlorophyll and photosystem II in order to produce an environmentally friendly and renewable source of chemical energy, namely Hydrogen gas. When combusted Hydrogen gas produces only water and energy - this is highly desirable from an environmental perspective⁴.

The Solar Synthesisers’ Project

To achieve this goal we're building on the ground-breaking work of last year's gold medal-winning Macquarie University iGEM team by transforming E. coli with the genes required to complete the chlorophyll biosynthesis pathway and create photosystem II in this bacterial species. These systems will allow for the use of solar energy to split water into positively-charged hydrogen ions, electrons, and oxygen. Our next goal is then to combine the hydrogen ions and electrons produced in this hydrolytic process in a hydrogenase enzyme complex in order to produce hydrogen gas on an industrial scale. Hence in order to produce a renewable and environmentally-friendly source of energy we present the Solar Synthesisers’ 3 step plan: Capture, Transfer and Synthesise!

Capture

In order to capture light energy from the sun we aim to use chlorophyll pigment to capture photons. We aim to transform and express within E. coli the 13 genes required to complete the chlorophyll synthesis pathway in this species.

Transfer

In photosystem II the energy captured by the chlorophylls is used to split water into protons, electrons, and molecular oxygen.

Synthesise

The next step is the combination of two protons and two electrons in a hydrogenase enzyme complex to synthesise hydrogen gas. The commercially-viable production of industrial quantities of hydrogen gas will represent the successful completion of our project.

References

Please see our References page for the list of citations.