October 2010 | Gayatri Kamath

Botanical bounty from a killer weed

A unique thought process led the Tata International R&D team to use poisonous parthenium plants to create a cheap and environment-friendly preservative

Don’t let the grass grow under your feet, runs the old maxim. And when it comes to the highly noxious parthenium weed, which has been declared a health hazard in several states of India, the maxim makes eminent sense.
A project targeted at controlling this toxic weed and, while doing so, extracting an anti-microbial agent from it has fetched the two-member team of S Saravanabhavan and Anupama Pati from Tata International’s R&D division the much-coveted Leading Edge innovation award.
The duo chose to work on a critical health and community issue that affects most of India today — the widespread proliferation of parthenium, also known as Congress grass or Gajjar ghas — and has come up with a unique solution that promises several social, environmental and economic benefits.
Out in Dewas, Madhya Pradesh, where Tata International’s leather and leather products business unit is located, the parthenium weed has, over the years, been growing ever stronger and getting more entrenched. Parthenium is not native to India, but it has spread like wildfire across large swathes of both farm and waste land and now covers an estimated 35 million hectares across the country.
Green toxin
There is a reason for the weed’s evil reputation: When its seeds burst, they disperse fine pollen that spreads in the air and causes severe respiratory diseases in man as well as beast. Each parthenium plant grows thousands of these pollens that, when inhaled, clog the airways, nasal passages and lungs. It is one of the main causes of asthma in human beings, especially children, and cattle across India. In bovines, parthenium can cause a drastic drop in the milk produced.
The plant is so poisonous it can neither be used as animal fodder nor as biomass for fuel. When parthenium covers the land, its roots weaken the soil and farmers are left with depleted agricultural yields, which can fall by as much as 35-40 per cent.
India’s Union Ministry of Environment and Forests has allocated funds for research to eradicate parthenium. The challenge is that even herbicides don’t have too much of an impact on the weed, given its ability to flower in all seasons and reproduce rapidly. Attempts to pull the plants out by hand or to burn them results in the seeds bursting and releasing their dangerous pollen.
In December 2009, surveying the rapid growth of parthenium in and around Dewas and seeing its terrible impact on local communities, Tata International executive director OK Kaul spoke to his research team about the weed problem, suggesting that if the company could come up with a solution it would be a positive and much needed social responsibility initiative.
Early in 2010, Mr Saravanabhavan, deputy divisional manager of the R&D division, and Ms Pati, a microbiologist on the team, decided to take on the task of taming the pestilential parthenium. As the two started to study the killer grass, they realised it was a much tougher problem than they had bargained for.
Even collecting the weed for lab research was hazardous. Parthenium causes not just asthma and other lung problems, but it also leads to severe skin infections and dermatitis. The only way to safely handle the plant is by wearing protective clothing.
A close examination of parthenium’s characteristics revealed that even its roots are polluting, killing nitrogen-fixing microbes and lowering the fertility of the soil. To make matters worse, the plant has a natural ability to rejuvenate itself.
Managing the menace
But Mr Saravanabhavan and Ms Pati soon came to understand that not everything about parthenium was negative. Mr Saravanabhavan says, “Nothing in nature is all ‘bad’. Nature is balanced. There had to be something about this plant that was useful.”
The answer lay, surprisingly, in the plant’s very toxicity. An analysis of its biochemistry revealed that parthenium contained several phytotoxins: parthenin, ferulic acid, caffeic acid and chlorogenic acid. All of these have one characteristic that could be used to advantage. Given their strong anti-microbial and anti-fungal property, they inhibit the growth of microbes and fungus.
What Mr Saravanabhavan and Ms Pati did — and this is where the brilliance of their idea shines through — was devise a way to extract the phytotoxins of the parthenium plant and create an entirely new substance that could act as an anti-microbial agent.
First, the parthenium was collected, washed and dried. Then the phytotoxic substances were extracted through aqueous and non-aqueous systems. These extracted compounds were subjected to tests and their antibacterial and anti-fungal activity were analysed. The lab results proved beyond doubt that the extract — the substance has not yet been named, but the team has suggested calling it Parthex — acts as a natural preservative.
The first material for the trial of Parthex as a preservative was leather, in which Tata International runs one of its main business lines. When used on raw leather Parthex worked like a dream: It kept raw, untreated leather from catching mould or parasites for weeks. This meant that it had the potential to replace a synthetic preservative called thiocyanomethylthio benzothiazole (TCMTB) that is used in the leather industry for preservation purposes.
“Parthex is much, much cheaper to produce," says Mr Saravanabhavan. “TCMTB costs as much as Rs400-500 a kilo, whereas we can produce Parthex for as little as Rs60-80 a kilo.”
The peril tamed
Tata International is already working out the logistics of producing Parthex in the quantities that it requires for its leather business. The company has applied for a patent for the innovation and is looking at setting up a pilot-level plant for production.
“Parthex can be used in several other industries, too," says Ms Pati. “The target industries are wood and wood products, paper, paint and adhesives. Apart from the food, drug and cosmetics sectors, we feel Parthex can be used anywhere else as an anti-microbial preservative." The preservative industry worldwide is a multi-billion dollar market, with the wood and paint segment (along with other user segments that do not call for human or animal consumption) accounting for as much as 12 per cent in total value.
Yet the implications of this find are much more than monetary. For one thing, Parthex is a biodegradable and natural preservative with no environmental load. By coming up with a strong and valid use for parthenium, there is now a solution for its safe disposal beyond what farmers practise. By getting it out of the fields in large quantities, its seed and pollen dispersal will be reduced drastically, thus lessening its harmful effect on human beings and animals.
The domino effect could continue further, with Parthex primed to have a much wider socioeconomic effect by virtue of its ability to enhance crop yields and lower health-related costs. And, just as significant, the new product will have a positive impact on Tata International’s revenues.
Little wonder, then, that Parthex has won Mr Saravanabhavan and Ms Pati an award and recognition at the 2010 Tata Innovista programme. If innovation can be defined as an endeavour that brings about change, then there can be no doubt about the prospects of Tata International’s latest tryst with ingenuity.
Also read:

Painting the planet green

Sunshine in slime

Counting cost, reaping benefits

In search of thinness

A sunny idea

Ear to the ground

Sting in the tailgate

Tata Innovista 2010: Creativity in innovation