Natural colours from bacteria, mushrooms

2007
By Syed Akbar
Hyderabad, Nov 3: Natural colours obtained from bacteria, mushrooms and other fungi are all set to adorn clothes and crafts in the international market.
Pioneering research by Dr K Perumal and others on microbial dyes has produced an array of natural colours that could be used for dyeing clothes, stone works and handicrafts. These colours are eco-friendly and harmless both to the users and the manufacturers. Even dyes obtained from poisonous fungi are safe on the skin.
According to Dominique Cardon of Unesco, who is currently in the city to participate in the international conference on natural dyes, the colours obtained from fungi are unique in pattern and colour intensity. "A synthetic dye simply gives one colour whereas a dye obtained from fungus, mushroom or bacteria gives an array of colours. It is a cocktail of colours and is very rich in colour intensity and fastness," she said.
Dominique pointed out that the research on natural dyes from microbial agents by Indian scientists would revolutionise the world of natural colours and greatly benefit artisans and artists. "We have scores of coloured fungi and mushrooms. There are coloured bacteria too. Using industrial techniques the scientists obtained colours. These colours can be mixed in different combinations to obtain rare colour patterns," the French researcher pointed out.
Though dyes based on fungi, especially lichens, have been used for quite some time, the technique adopted by Indian scientists is the first of its kind. Colours like browns, yellows and greys are easily obtained from common fungi varieties available in the country.
The colours of the pH indicator, litmus, and various reds, yellows and mauve are also available especially when using appropriate mordants. The commonly used Litmus (of litmus test fame) is also a dye extracted from fungus of the genus Roccella. In alkaline conditions it is blue. As the dying conditions became more acidic, the colour changes from blue to purple and then red.
She said these colours can be fixed to the cloth by using an appropriate mordant. With the increase in the cost of petroleum products, manufacturers are increasingly turning to fungi for their colouring needs. The demand for natural colours has also gone up in the international market and the Indian dyes from fungi and bacteria are going to play a major role.