DEVELOPMENT: Indian State Cultivates Riches from Weeds

By Ranjit Devraj Reprint | | Print |

Ranjit Devraj

THIRUVANANTHAPURAM, India, Aug 29 2004 (IPS) - After reluctantly sharing their picturesque backwaters with the water hyacinths for decades, residents of the Indian southern state of Kerala have decided to put the fast-growing weed to commercial use by converting it into the industrially valuable enzyme, cellulase.

Leading the way is the Kerala state government, which is setting up a three million U.S. dollar demonstration plant at Akkulam, a suburb of this city with a large freshwater lake that serves as a naval base but is now almost completely overrun by what is often called the world’s worst water weed.

‘’We hope the project works. We are tired of this weed which has made life on this lake impossible,” said Aiyappan, whose fishing family lives in a thatched hut on the edge of the lake that glistens with the velvety green weed.

Aiyappan, who uses one name, said the weed has taken over the lake in the last 10 years. This has disrupted fishing activities and navigation and increased mosquito infestation in the area.

Over the years, people living in many tropical countries have tried to rid their water bodies of the unsightly water hyacinth, which clogs up inland waterways and irrigation canals and affects fishing and navigation.

But the fast-growing plant, which can replicate itself 3,000 times in 50 days, uses up vast quantities of water and nutrients and has easily overtaken efforts at physical removal.

Vexed authorities working as far apart as say Lake Victoria in Kenya to deltaic Bangladesh, Indonesia and Australia, have tried to convert the water hyacinth into leaf protein concentrate, animal feed, mulch, compost, biomass for biogas digesters – and even into briquettes as substitute for firewood.

It would seem as if the whole world is on the look out to convert this prodigal plant into something useful for mankind.

For instance, the Germany-based Projektwerkstatt imports furniture from Thailand, made from water hyacinth by the designer Khun Tuk, as do firms in North America.

In central Kerala, the Kuttanad Vikasana Samithi, a voluntary organisation, has perfected a method of making bags, mats and even carpets out of fibre taken extracted from the stems of the weed by boiling.

But the stubborn weed has always worn down such ‘appropriate technology’ efforts, many of which have turned out to be unviable for impoverished communities scratching out livelihoods in the impoverished rural settings of the developing world.

The Kerala initiative follows the discovery by scientists at the National Environment Engineering Research Institute (NEERI) at Nagpur, central India that water hyacinth could be used to readily and cheaply produce cellulase, an important enzyme used in the world’s burgeoning biotechnology industry.

All plants produce some cellulase, but only a few like the water hyacinth contain sufficient amounts for commercial exploitation.

Cellulase is used mainly for breaking down cellulose (from the pulp of fruits) into edible glucose, for industrially improving the quality of cotton textiles and paper. Current world production is estimated to be around 500 million U.S. dollars.

The animal feed industry uses cellulase to convert fibres in waste sludge into sugars and improve the efficiency of anaerobic water treatment processes.

Credit for making practical use of the idea must go to officials of the Kerala Bureau of Industrial promotion (KBIP), which has proposals pending with various agencies such as the Global Environment Facility (GEF) to see if the technology could be used in other developing countries.

According to Ajith Kumar, a KBIP official, the process is viable because of its sheer simplicity involving nothing more than fermenting the leaves and stem and then allowing the pulp to be attacked by a fungus called Trichoderma reesei, which precipitates the cellulase.

‘’The roots of the weed can be used to generate electricity through biomass gasification and this can be used to reduce overall costs of running the plant,” said Kumar.

The best thing, said Kumar, is that the plant will never run short of raw material except for chemicals like acetone and calcium chloride, which are used to purify the cellulase produced by the digesters.

India currently imports all the cellulase it needs from countries like the United States and Germany, which use expensive manufacturing processes that have questionable safety and issues.

Meanwhile, the water hyacinth is turning up at unlikely places on the subcontinent.

In north-western Punjab, it is posing a threat to fish species and turtles in the famed Harike wetlands, which are spread over a 41 square-kilometre lake on the confluence of the Sutlej and Beas rivers that flow into Pakistan.

‘’Already the water quality on the wetland is impaired by the weed,” said Satnam Singh Ladhar, scientific officer with the Punjab state government.