The starting recipe here is relatively simple, the outcome most definitely not. Two initially white pigmented bacteria Erwinia carotovora and Chromobacterium violaceum, CV026, (or two living and “intelligent” pigments), have been mixed together. CV026, is a mute strain, its ability to communicate with itself, and other bacteria having been genetically disabled. If however, it detects communication signals from other bacteria it will respond to these by producing a purple pigment. Erwinia carotovora is an unrelated species that produces such a communication signal. The painting begins life as a white splodge, as if an artist had painted white acrylic or oil paint onto a canvas, but unlike conventional paints, as the two living pigments interact, and communicate with each other, a complex and unique autogenic glyph emerges. I like to think of these as bacterial versions of Keith Tyson’s Nature Paintings.
Forget the Queen’s Christmas speech and the Popes! These festive “glyphs” were generated just by the process of bacteria communicating with each other. Sometimes, I imagine that they might also be using these glyphs to communicate with us. This is what they had to say about Christmas!
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 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.
In the above images I’ve inoculated the sensor bacterium CV026 and a signal emitting bacterium into a matrix. Initially, both strains are white and indistinguishable from each other but upon incubation ,and as they communicate with each other, a hidden cypher is revealed as the reporter strain detects the signal and turns purple as a consequence.
This work explores my concept of “Microgeography” which amongst other aims, embraces playful and inventive strategies which might take pedestrians off their predictable macroscopic paths and jolt them into a new awareness of the urban microbiological landscape. Here is such an intervention. Where there is opportunity life always finds a home. Fractures in the hard manmade continuum of our urban environments, cracks harbour overlooked but wondrous ecologies that are all underpinned by microbial activity. Here the natural ecology of a crack between concrete paving stones in a public has been carefully and secretly removed and replaced by a natural deep marine ecology containing bioluminescent bacteria in order to draw attention to what is normally overlooked.
These glass cassettes are prototypes for a project to adapt bacterial bioluminescence to make a novel form of mood lighting for homes . In Nature, this form of light is often employed by predators as a lure, and like a form of biological temazepan, it has unique hypnotic and calming propeties. I also placed the light cassettes onto an old overhead projector to determine whether the bioluminescent light could be projected onto a surface. It can be and I’m currently imagining a way to make a pure beam of laser-like biological light.
I’ve done at lot to promote the better side of the Earth’s microorganisms and bacteria in particular. Are they grateful? I have to say no! In September 2011, I became seriously ill, only to find out that the cause of the illness was a species of bacterium called Streptococcus mitis that had set up home on my aortic heart valve. The disease is called endocarditis and is fatal unless treated but fortunately for me, it was sensitive to penicillin (a disturbingly rare vulnerability in bacteria these days). I spent a month in hospital, and after a month’s intensive antibiotic therapy the unwanted bacterial guest had disappeared. I found out after the infection, that the same bacterium had also survived for over two years on the Surveyor 3 probe on the moon , so that a little lunar outpost of earthly biology and my heart are intimately linked over many hundreds of thousands miles of space. These are photographs of the bacteria in my blood, taken by an obliging hospital microbiologist. The bacteria are the small purple chains amongst the larger red objects which are my blood cells.
The spacecraft Voyager 1 has just arrived at the most distant part of space that can be considered part of our solar system and which NASA has described as “a magnetic highway for charged particles”. This font, using bioluminescent bacteria, was made in my lab by artist, Anna Garforth. The neat font of the artist though has now been embellished and given apparent motion by bacterial activity, so that the edges of the letters appear to have been ablated off into space, and as if they has been exposed to some unseen yet powerful stream of charged particles.
A clear night sky filled with stars and constellations that shimmer with their own haunting luminescence? No. An agar plate containing many hundreds of microcolonies of bioluminescent bacteria. There is a subtle juxtaposition here, the stars, defined by the inflexible physical constants of the Universe, seemingly timeless and permanent familiars in our night skies, represented with the mutable and ephemeral phenomenon that is biology.