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Sunday, 1 July 2012

The marvellous ways of the Nature: And now colours and dyes from bacteria, fungi and lichens


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, yelloTws and greys are easily obtained from common fungi varieties available in the country.



By Syed Akbar
Hyderabad: 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, 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, yello
ws 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.

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