CSIRO scientists discover how to grow colored cotton
Updated: May 27, 2021
A few dozen petri dishes in a high-tech greenhouse in Canberra hold the potential to transform the global textiles industry.
They contain plant tissue, which within days will grow into cotton plants: not standard, everyday white cotton, but ones with a dazzling array of colours.
They are the product of CSIRO plant breeders dedicated to producing better, sustainable natural fibres that will hopefully one day lead to wrinkle-free, naturally dyed, stretchy cotton to outperform synthetic fabrics.
Colleen MacMillan leads the team of scientists who have cracked cotton's molecular colour code, adding genes to make the plants produce a colour.
"Having the cotton produce its own colour is a game changer," Dr MacMillan said.
"We've seen some really beautiful bright yellows, sort of golden-orangey colours, through to some really deep purple," fellow scientist Filomena Pettolino said.
It will be several months before the colourful plant tissue they have created grows into flowering cotton plants; only then will the scientists be absolutely certain of their success.
But everything points that way.
Another positive sign is that coloured cotton genes, inserted into green tobacco plants, have shown up as coloured splotches on the leaves.
If the leaves of the biotech (genetically modified) cotton are coloured, the all-important fibre will be as well.
For the scientists involved, the discovery was a eureka moment.
"When we saw the results, it brought a tear to my eye because it was a very special moment," Dr MacMillan said.
"We didn't believe it would happen."
A win for sustainability
Australia's cotton industry, worth about $2 billon annually, will be a major beneficiary.
While cotton is renewable, recyclable and biodegradable, it still needs to be dyed, and the use of sometimes harmful chemical dyes is considered a blot on the industry's environmental copybook.
Particularly significant is the CSIRO team's work to breed naturally black cotton to replace black dyes, which are regarded as the most polluting of textile colours.
Cotton Australia chief executive Adam Kay is watching the scientists' work closely.
"We've done all these things to improve our environmental credentials, but still the use of dyes is something that can have an impact on the environment," Mr Kay said.
It's estimated that on average, each Australian produces about 25 kilograms of textile waste each year.
Much of it is synthetic and it ends up in landfill, where it will take hundreds of years to degrade.
Dr MacMillan said there was a growing awareness of the environmental cost of fast fashion.
"This [research] can really have the potential to transform the global textile industry, because we're making fibres that are still biodegradable, still renewable, but still have properties that they don't currently have," she said.
"That's a big deal for sustainability."
Dr Pettolino said a move away from synthetic materials in favour of cotton would be an important step in protecting the environment.
"Synthetic microfibres end up staying in the environment and can do more damage than regular plastic, so it's important we move away from that to safeguard the environment," she said.
The team is also working on a longer-term project, creating wrinkle-free cotton that doesn't require ironing.
It means screening and testing thousands of cotton plants to transform them into new super-cotton varieties to produce fibre with greater elasticity that can compete with synthetics.
Towards compostable clothing
Sydney lingerie designer Stephanie Devine welcomes the work going into cotton varieties to replace synthetics.
When she learned the textile industry was the second-most polluting in the world, she set up a crowdfunding campaign to produce the first compostable bra that is strong and stretchy but uses no synthetics.
She said it was an enormous challenge.
"I've been sourcing material from all over the world," Ms Devine said.
"I had to find tree rubber, an organic cotton [which is] elastic so it has good stretch, but is also able to be eaten by worms or composted."
Despite the challenge in securing biodegradable materials, she has been able to make underwear for the "circular economy" that can biodegrade.
She hopes CSIRO's work will bring about broader change in the industry.
"On average, 60 per cent of our clothes are actually made of polyester, which lasts 200 years in landfill, and we typically only use natural fibres in 6 per cent of our clothing," she said.
"There's a real imbalance there, and I think that we're beginning to shift that, but natural fibres, cotton, wool, Tencel are really the way that we need to be going as an industry."
Author: Tim Lee