Future Work: Characterising the light sensors

First on our list of priorities is to fully characterise the various light sensors - Cph8, LovTAP, and CcaS. Further characterisation of the light sensing systems should occur under different intensities of light, to test whether increasing the intensity allows the acquisition of improved data as the current light levels may not be sufficient to activate the sensor systems. Also required would be experiments to characterise the expression levels of the sensors and their requisite signalling pathways, as well as investigation of methods to increase this, as it is possible that current expression levels are not high enough for transformed bacteria to be able to accurately detect light. Finally, experiments using different reporter systems may allow us to further assay the sensors and build up a suitably large amount of characterisation data.

Future Work: Light communication

Initially, we would need to dedicate our efforts to the characterisation of the individual light producing and light sensing components that make up the FORTH framework, as well as conduct the possible experiments and further mutations that would be needed to match up the wavelengths between the appropriate counterparts. Eventually, however, we would like to develop a biological system that successfully demonstrates the concept of communication via light.

This could be achieved using a system of two cultures separated by a transparent glass divider, such that light could pass between the liquid cultures but chemical messengers could not. The first culture would contain bacteria with a specific emission system under the control of an inducible promoter; the second culture would contain bacteria containing the appropriate sensor system, coupled to an appropriate reporter such as urease production or something equivalent to control the pH of the culture. This would allow easy detection of the reporter and therefore prove that communication between the bacteria had occurred.

If this is a demonstrable success, we would then be able to move on to building more complicated systems, such as the repressilator that we have modelled as part of our project.

Future Applications

A particular focus was placed this year on the broader applications of our work in terms of how it could be used in the future. Since we were working not only with light production but also light sensing and the broader concept of bacterial communication via light, we had a wide range of plausible applications for the technologies that we sought to develop. A number of novel ideas were put up for debate, some of them detailed separately here.

One immediate application that almost instantaneously springs to mind is the use of light production BioBricks as reporter systems for biosensors, and of light sensing BioBricks as a means of enforcing the action of said biosensors. We can foresee the use of multiple light outputs in a single sensor (for example, glowing red in the presence of arsenic and blue in the presence of mercury), as well as the development of modular biosensors in which the detection and reaction components did not have to be intrinsically tied together.

A second idea that was extremely popular not only with the biologists but also with the informaticians was bacterial communication with computers. Computers can be used to direct light-based bacterial responses through the application of short bursts of LEDs, and can then detect the corresponding response in turn. In this way, one can envision computers and bacteria 'talking' to each other via short bursts of light... an intriguing thought with a large number of potential applications!

A third idea, already embodied within the modelling component of our project, was in the use of light-based communication to synchronise colonies of bacteria physically separated from one another. This would have a massively beneficial effect on many synthetic biology applications, for example the repressilator system detailed previously, which has as a major drawback the fact that the cells involved fall out of synchronisation after a short period of time.

Our discussions also envisioned various commercial novelties based on bacterial light creation and detection. From lamps to body paint, glowing animals to bioluminescent trees, they quite literally ran the whole gamut of plausibility. We even talked of personal bacteria-based tags that would glow a certain colour in reaction to particular conditions, and nearby walls that would react appropriately by sensing the glow!

One final, and perhaps extremely useful, application that was discussed was the creation of a light-based PoPS measurement system. Although it was never formalised to the extent that it would be a practical protocol, it gives a tantalising glimpse into a future where one day, perhaps, BioBrick parts may be fully characterised in a standardised manner!

Throughout this wiki there are words in bold that indicate a relevance to human aspects. It will become obvious that human aspects are a part of almost everything in iGEM.