Just a few colonies from C-MOULD, a collection of characterful microorganisms for use in BioArt and BioDesign.
It is not generally widely known, but bacteria possess complex chemical communication systems that endow them with a kind of social intelligence. In the simplest sense they are able to signal their presence to other related bacteria and through this census-taking, ensure that their communities express only specific functions at particular population densities. These systems also allow bacterial communities to vote on issues affecting the entire population, and allow bacteria to function as multi-cellular organisms.
Chromobacterium violaceum is a common soil bacterium that produces striking purple colonies. In relation to the concept above, the expression of this colour is dependent on bacterial communication so that when a small number of bacteria are present it will be white but it turns purple when it receives a communication from other bacteria. When it grows in colonies, individual bacteria of these species are continually sending and receiving signals and consequently the colony will be purple. I have a genetically modified version of this bacterium (CV026) that is effectively mute. It can receive chemical communication signals and respond to them, but cannot send them, so that it only turns purple if it detects a communication signal from another bacterium. In this sense, it is a unique sensor for bacterial communication giving a striking and direct visualization of this phenomenon. These are experiments with CV026. Where you see purple in the images, CV026 has detected and responded to communication signals produced by other species of bacteria.
Enormous floating rafts of plastic debris in the oceans highlight the impact of plastic pollution, and rightly so, have attracted the focus of environmentalist and scientists alike. However, more recently, the impact of the less visible side of plastic pollution is raising serious concern.
Plastic micro beads are widely used in toiletry products like facial scrubs and toothpastes. Unfortunately, they pass through sewage treatment plants and vast quantities of them enter into natural water courses. Concentrations of as much as 1.1 million fragments of microplastics per square mile have been found in some natural water courses. Here, fish and other aquatic organisms eat them along with any pollutants that they might carry. but these micro fragments of plastic do not just mimic food and they can also cause physical damage to many organisms. Here is a short experiment in which the elegant microorganism Volvox aureus is exposed to a suspension of plastic microbeads , with devastating impact!
Inspired by Bacterial Wargames, I’ve started exploring the interaction of pigmented bacteria with textiles again, with a view to making a brightly coloured dress using only bacteria from the human microbiome to produce the colours and design. I came across this old project that I had with artist Anna Dumitriu, a white embroidered dress in which the colours are due to pigmented red and purple bacteria. I was struck by the way in which the bacteria infiltrate the intricate shapes, and give them an unexpected life.