The extracted pigments ready for textile tests
The naturally pigmented bacteria and source of the BioDyes
How often do we think about the origin of the dyes used to colour our clothing. Almost, without exception they are, synthetic, and also the products of unsustainable chemical processes. The is a project with Anna Dumitriu and Sue Craig to explore whether natural and sustainable bacterial pigments can be used to dye textiles. The red pigmented bacterium Serratia marcescens and the purple pigmented bacterium Chromobacterium violaceum are the starting points.
This exploration was inspired by the current hot weather and the thought that two other life forms seem to benefit from it.
The blue bottle fly, Calliphora vomitoria (the latin name says a lot about it) is a very common and cosmopolitan insect, with which we share many of our environments. This fly seems to be equally at home feeding on rotting bodies, faeces and our carefully prepared food and this, and other habits make it an unparalleled vector for transmitting disease. It prefers to swallow liquid food, and usually regurgitates ingested material in order to liquefy its meal and to facilitate digestion. In this manner flies can contaminate clean surfaces with approximately 0.1mg of food per landing. In addition, droplets of bacteria rich faeces may be deposited during feeding, about every four to five minutes. Finally, if a blue bottle has recently fed on faeces it may carry as many as six million bacteria on its feet.
I developed a simple process to reveal the way in which flies carry and transmit bacteria. I trapped three blue bottle files in a large square plastic dish filled with solid bacterial growth media and allowed the flies to walk over the surface for just 10 minutes. As the flies travelled over the uninoculated surface they left behind a trail of the bacteria in their footsteps. Because of the invisible nature of bacteria, these tracks were at first invisible. However, after a day or so the bacteria grow into visible points (or colonies) that reveal the activity of the flies and the extent of their contamination. I must admit that even as a well-seasoned microbiologist , these images make me slightly queasy. (Not flies were harmed during the making of these images)
The printed bacteria from the toilet biofilm viewed under normal light
The printed bacteria from the toilet biofilm viewed under UV light and revealing their glowing message.
Here’s some BioArt that I carried out at home using DIY Bio. Anyone could do this. I found a bacterial biofilm growing under the rim of the toilet in our en suite bathroom (I suspect that even the cleanest of toilets will have these). Using General Kitchen Agar (GKA), a bacteriological medium that can be made at home and with ingredients that can be purchased at any supermarket, I cultured the bacteria from the biofilm. When the bacteria are visualized under a UV/Blacklight (again readily available) they can be seen to be highly fluorescent (the ones that appear to glow blue) and because of this are probably Pseudomonas species. I purchased a bespoke rubber stamp, used these bacteria as a living ink, so that when exposed to UV light they reveal a pertinent message!
Am I concerned with this apparent lapse of home hygiene? Not at all, it’s just another striking example of the ability of bacteria to adapt to the new environments that we seem to perpetually, and unintentionally, create for them.