Team:UCL/Enterpreneurship/Product
Product Development & Manufacturing
Product Overview
Our LIT bulb is powered by the co-culture of two types of cells: Cyanobacteria and engineered E.coli cells. Both cell types have been programmed to symbiotically coexist and produce enough luminescence to light up a street on a nightly basis. Cyanobacteria will be engineered to secrete the glucose product from photosynthesis, thus they would be unable to sustain their growth when competing against other microbes in the environment if they were to be released.
How the LIT bulb works
Figure 1: Components of the LIT bulb designd with Pictochart
When sunlight is present the biological switches present in our cells become repressed and luminescence is not produced from our cells. Oppositely, during the evening when light is not present, our biological switches become activated and luminescence is produced. As such, the LIT bulb is fully automated. We used Cyanobacteria cells, which photosynthesise, to produce the nutrients required by the E.coli cells to luminesce; and relied upon the E.coli cells’ respiration to provide the nutrients required for the continued survival of the Cyanobacterial cells.We then created a unique LIT bulb design which allowed for uniform lighting while at the same time maintained the correct conditions needed for the continued survival of the two cell types.
Design considerations
Our original idea was to create genetically engineered cells that would not require any electrical or mechanical input to keep cells suspended in a culture. However, we soon realised we would be facing homogeneity issues due to heat and nutrient transfer if we did not come up with a design that could continuously re-suspend our cells inside our lightbulb. So we invented that too. We created a rotor that gently moves the cell cultures around such that they are always in correct suspension and equilibrium. We also considered the high energy strain of the cells due to luminescence production, temporary/limited food source, robustness/safety/biocontainment, permeability to oxygen (gas exchange) and human perception.
| Criteria | Conventional lightbulbs | LED lightbulbs | Lightbulbs with motion sensors | Bioluminescent lightbulb |
|---|---|---|---|---|
| Scale of project meets the needs to replace the lightbulbs in London | √ | √ | √ | √ |
| Environmental impact | x | x | x | √ |
| Maintenance costs | x | x | x | √ |
| Upfront costs to implement the technology | √ | x | x | x |
| Power/ light intensity of lightbulbs | √ | √ | √ | √ |
Figure 2: Summary table of the six major criteria evaluated for all Streetlight technologies
We developed mathematical models to determine the optimal dimensions of the light bulb as well as the quantities of each microorganism required to provide the maximum amount of luminescence possible (160W). The circular structure of the LIT bulb maximizes the exposure of Cyanobacteria to sunlight. We introduced a pump to ensure the cells remain suspended and the cell culture is homogeneously distributed throughout the LIT bulb. We also added a three-way manual valve to allow for the easy replacement of media once every 12 months. We will add a filter to the valve to allow media to be replaced without removing the cell culture. To validate the robustness of our product we would conduct a series of experiments to optimise the shape and components of the LIT bulb using the data we have obtained from our OptoFlux design model. The LIT bulb has been designed such that it fits inside the conventional streetlamps in London.
- Figure 3: 3D prototype designed in Autodesk Fusion 360.
Manufacturing Practices
Lighting alone consumes 19% of global electricity and electricity is the largest contributor to greenhouse gas emission, accounting for 25% of global carbon emissions. In the UK (2005), street lighting was using approximately 3.14 TWH of electricity giving rise to CO2 emissions of 1.32 megatons. We are addressing this environmental impact with the use of synthetic biology, a cheap and eco-friendly alternative to electricity powered lighting technologies.
- √ Lower CO2emissions
- √ Low maintenance Costs
- √ cGMP guarenteed
We decided to approach the development of our LIT bulb by adopting the the conventionally used engineering design cycle, as it perfectly reflects the design of our LIT bulb. We want to constantly update, improve and adapt the LIT bulb to technological progress, changes in the market and new policies.
The final LIT Bulb design aims to provide a long-term stable light source. We plan to engineer E. coli cells to bioluminesce only at night time to minimise the energy strain of bioluminescence production, and to engineer cyanobacteria to perform their natural photosynthesis but secrete the glucose product to feed the E. coli cells for their long-term survival. The oxygenic photosynthesis by the Cyanobacteria will simultaneously reduce the amount of carbon dioxide in the atmosphere. Our aim is to create organisms that can only reproduce and survive under artificial conditions. To do this, we envision running our own experiments which will be aimed at evaluating which bacterial strains grow solely in the presence of very low levels of specific gases, namely Oxygen gas. We would also test our LIT bulb under extreme environmental conditions to ensure that luminescence would be produced by our bacteria under the harshest of environments.
The future of the LIT bulbs
We decided to envision the implementation of our product, the LIT bulb, using a “think global, act local” approach. We examined and quantified the economic, social and ecological advantages the application of the LIT bulb would have in the U.K. and extrapolated these results onto the world. We also worked on tweaking our original idea to include a further safety measure that could assuage public concerns about leakage of genetically modified organisms into the surroundings. Our long-term future thinking includes making LIT bulbs that can be used for lighting billboards, gardens and outdoor venues.
Safety
According to the GPP (Green Public Procurement), a public street light can be defined as:
“Fixed lighting installation intended to provide good visibility to users of outdoor public traffic areas during the hours of darkness to support traffic safety, traffic flow and public security”.
The aim is to install the LIT bulb in conventional LIT bulb all around London, our product will constantly be exposed to the general public. At LIT we put a lot of weight on the security and opinion of our customers. Hence, we have established internal policies to ensure a safe use of the LIT bulb and to diminish the negative view associated with GMOs.
To tackle public concerns for using genetically engineered cells we will set up LIT bulbs in small communities and educate the public about the scientific steps involved in the production of bioluminescence from cells and showcase the fool proof safety measures involved in its workings.
The 21st century is an era of high tech and incredible technological advance, where authorities and governments aim to implement new technologies in any areas of public life. Yet, whenever a new product is introduced to the market, the regulations in place have to be considered. We worked on tweaking our original idea to include a further safety measure that could assuage public concerns about leakage of genetically modified organisms into the surroundings. In case a LIT bulb broke (e.g. from a car accident) and the genetically engineered bacteria were released into the environment, the cells would die immediately and as such verify that they would not pose a threat of bio-contaminant .
