Future Directions

Our work with creating a system of inducible electrical output in Shewanella has laid the foundations for many different exciting avenues of further inquiry which look to take advantage of a bacteria-computer interface that combines the amazing sensitivity and adaptability of bacteria with the speed and analytical abilities of electricity and computers.

Using the same principles underlying the lac system, the arsenic biosensor developed by the University of Edinburgh iGEM 2006 team could be introduced into Shewanella, allowing for the coupling of arsenic sensing to an electrical output, a form of a data which is easier to automate and transmit. This could be further extended to other chemical sensing systems, resulting ultimately in an array of different strains Shewanella which all respond to the presence of different chemicals with an electrical output that can be monitored by a computer. This could theoretically allow for the remote sensing and analysis of the chemical composition of an environment over time.

Another interesting direction would be the linking of the light-sensing system developed by the UT Austin iGEM team with electrical output in Shewanella. In response, to changes of light the amount of electricity produced by Shewanella could change. This would allow for the intriguing possibility of not only Shewanella conveying information to the computer, but also the computer responding to the Shewanella. A simple example would be that in response to a chemical input, Shewanella may increase its electrical output. Sensing this increase, the computer could turn on or off a light directed at the Shewanella, modifying Shewanella's output, creating interesting feedback loops. This could ultimately be developed into more complex communications systems between bacteria and computers.

The possibilities are further broadened by our observations of co-cultures of E. coli and Shewanella. Either of the systems described above could be pursued through an alternative alternative strategy of co-cultures. For instance, an array of E. coli which respond to different chemicals by breaking down lactose into lactate could be cultured with Shewanella. In response to an increase in lactate, Shewanella would begin to produce higher levels of electricity. Co-cultures could also allow for more complex bacteria-computer interactions. This strategy could enable the coupling of almost any E. coli ability to electrical output.

These future directions in which our research can be taken demonstrate some of the exciting possibilities of BACTRICITY!