The Winogradsky column is a simple device for culturing environmental bacteria and is an elegant means of demonstrating their vast diversity and complex interactions. Invented in the 1880s by Sergei Winogradsky, the device comprises, a column of pond mud that has been fortified with a carbon source and a sulphur source. The column is exposed to sunlight for a period of months to years, during which aerobic/anaerobic, and sulphur gradients form. All of the bacteria in the mud column are present initially in low numbers and are thus not visible to the human eye. However, during the incubation, different types of microorganism will come to occupy distinct zones where the oxygen and sulphur gradients generate specific environmental conditions, and niches, that favour their particular growth requirements and specific activities. In these zones, particular bacteria proliferate massively to form visible and brightly coloured communities.
Here I intervened by differentially exposing a Winogradsky column to light. This influenced where the specific types of bacteria were able to grow, resulting an image being generated by and recorded in the vast bacterial community. 3 months exposure.
After the mask has been removed to reveal the image, and as the bacteria are exposed to uniform light once more, the figures change as they become repopulated by green photosynthetic and other bacteria. In a sense, I see this as a type of alternative photography where the emulsion is a massively complex microbial community that responds to light. The ecology is perpetual and continually changing in response to its environment so the image never becomes permanent or fixed, but even if it disappears completely its legacy is preserved in the changes and influences that it made to the ecology.