Digital Bacterial Chip

Hi:

Here is a computer chip made out of bacteria: http://www.guardian.co.uk/science/blog/2009/jul/24/bacteria-computer

Reading that article caused me to daydream about a similar but speculative computer chip made of cells of the smallest existing bacterium with the following characteristics:

1. Aerotolerant-anaerobic

2. Non-pathogenic

3. Non-allergenic

4. Not gram-negative

5. LPS-free

6. Use homolactate fermentation as their only source of energy

This chip uses bacterial cells and their connections in place of silicon and electric circuits.

In electronic chips, electrons are what make up the intelligable signals. A bacterial chip would use chemicals in place of electrons. What chemicals would be used? Proteins?

Thanks,

GX