Heading to the unknown, mankind is striving to protect its wealth of knowledge. A safe haven seems to lie in the simplest creatures on earth, microbes. The DNA of these organisms can last for millions of years as they brave the hot and cold. Our Bio-information group has explored the recent advances in this area, where new, more efficient strategies to encode digital data in microbial DNA have been developed lately.
From a different point of view to the topic, I focused my research on using biological materials in transferring electrons as a different aspect of transferring information. Many different types of biological materials have been explored as potential nanowires such as DNA molecules, protein fibers and bacterial structures.
Bacteria have long been studied for its ability to both generate and conduct electricity. Long ago researchers started to think of sustainable microbial fuel cells after discovering some bacteria that feed on complex organic waste and generate electricity in the process. Later on, strains of bacteria were found to be able to eat pure electrons from rocks and minerals or excrete them. The most interesting is the discovery of some strains that can do both, eating and excreting electrons, by forming long chains of connected cells forming what is seen as ‘power cables’ making their way to reach oxygen. What links these cells to one another and also passes electrons between them is filamentous peptedic structures that stick out of their cell surface.
These filaments act as highly conductive wires due to their amino acid content and sequence. Studying this content, researchers recently found that some replacements in this sequence with amino acids that are more effective in electron transport would result in even higher conductivity. This was achieved by genetically modifying these filaments genes, resulting in filaments that are more conductive and have more desirable features.
As we do not know how life would be in the future, using bacteria to store information, generate energy or transfer electricity seems to be very attractive, particularly because these organisms can live in extreme environments, can feed on different sources, and are found in large populations. Although it sounds extremely challenging at the moment, perhaps one day we could generate electricity solely from microbes. It would probably need tremendous populations of bacteria to generate a little energy, but this also warns us how we are now irresponsibly draining the earth’s natural energy resources.
Another reason why we would use these bio-wires is that it could hold lots of medical, environmental and industrial applications, such as bio-robots, biological computers, medical devices insides human bodies. We could even get our own microbiota to electrically interact with our bodies to treat neurological disorders. Who knows how these single-celled creatures could surprise us?
- Tan, Y., Adhikari, R., Malvankar, N., Pi, S., Ward, J., Woodard, T., . . . Lovley, D. (2016). Synthetic Biological Protein Nanowires with High Conductivity. Small, 12(33), 4481-4485.