Transient images uses bacteria capable of degrading textile dyes (i.e. azo-dyes) to form images. The dye is converted into an intermediate substance that appears clear under anaerobic (without oxygen) conditions and dark blue in aerobic (with oxygen) conditions. Video shows degradation over 16 hours.
The image changes from a dye colour, such as orange, to a clear solution and further to a blue colour when oxidized. A matrix of bottles with increasing amount of inoculum (bacteria culture) was used to generate an image during breakdown, appearing and then disappearing. It is this transient state of image formation that gives the work its name.
Transient images is three-folded: (1) It sets out to generate image compositions through the processes of degradation and oxidation. These can be understood as positive or negative images where the first image is produced by loss of colour and the second by gaining colour through oxidation. Mixing dyes produce more complex colour changes. (2) The breakdown process allows harvesting electric current to power a light source for the display. (3) The blue by-product is toxic but can be made non-toxic by introducing the fungi Pleurotus. The fruiting body of the fungi specie is known as oyster mushroom making the display both detoxifying and edible.
Pleurotus growing in Potato Dextrose Broth after 1 week
The artist Marta de Menezes has previously explored azo dye degradation using bacteria, in her work Decon. A custom-made petri dish was used to separate rectangular agar slates containing coloured azo dyes (link to video). Her work mimics Piet Mondrian’s compositions with blue, red and yellow and has been exhibited as a wall-mount similar to paintings. Decon vanishes as time progresses. Interestingly, the work was accidentally contaminated causing fungal growth.
Various dye powder from the textile industry
Transient Images impinges on a major environmental problem in the textile industry - surplus dyes that are difficult and expensive to remove safely. Particularly, this work focuses on breaking down azo dyes and azo pigments that include artists’ paint. Azo dyes have excellent colouring properties and are resistant to light-reduction. But they can also be toxic and for instance methyl orange, an azo dye used in titration (e.g. colour variation based on pH-value), have mutagenic effects. The work was developed through discussions with Eustace Fernando whose research use sludge bacteria to breakdown dye and simultaneously generate electricity. Materials and methods generated through Fernando’s research were helpful in locating artistic potentials.
Dye conversion processes in integrated setup to generate electrical power
There are several bacteria capable of degrading azo dyes and act as electron donors. Shewanella aneidensis, is perhaps the most commonly used specie capable for accomplishing the task, however, it is a strict anaerobe. Fernando optimised this process by creating a consortium from sludge or sewage water using a wynogradsky column to acclimatise these to withstand various oxygen conditions.
Wynogradsky column
The bacteria are grown in semi-defined media that combine solutions of vitamins, trace elements, amino acids, base and sugar with azo dye. In order to accomplish a conversion to colourless, the solution was prepared in a vial with a butyl stopper and purged of oxygen.
Solution with media components
The following are examples of dye degradation:
Acid orange-7 story:
Orange → Colourless (Anaerobic) → Brownish (Aerobic)
Methyl orange story:
Orange → Colourless (Anaerobic) → Dark blue (Aerobic)
Other dyes with interesting properties include fast kinetics in ‘Re-active Red – 195’ and the corrugated colour of the anthraquinone dyer ‘Acid Blue – 62’.
On a more abstract level it is useful to note the chemical reduction processes as it provides insight into the reaction. This begins by taking note of the generic formula for azo dyes, written as: R-N=N-R'. Bioaugmentation of azo dye is still unclear but it has been suggested that the following takes place:
R-N=N-R' + 4e-+4H+ → R-NH2+R'+NH2
In other words a bacterial enzyme (dehydrogenanse) liberates electrons that may be used to produce electric current and in doing so break the double nitrogen bond and form colourless solution of amines.
Transient Images is a process based living work with multiple stages. The use of several organisms also suggests an evolutionary process.
In its final stage, Transient Images questions our confidence in the sciences. Starting from a hazardous dye that is converted into toxifying compounds, do we place our trust in the sciences, and eat the ‘harmless’ oyster mushroom grown from the detoxifying fungi?
Acknowledgements:
The work was conducted in 2011-2012 and the inital compositions in January 2011 - March 2012 at the University of Westminster.
Sincerest gratitude to Dr Mark Clements. Special thanks to Eustace Fernando.
The research is supported by a Doctoral Award from the Arts and Humanities Research Council and University of Westminster.