NAGPUR, Jan 19: A group of city researchers have developed a process to utilise water hyacinth, a common aquatic weed with nuisance value, for the production of cellulose, an important enzyme with industrial applications.
The group of scientists from the National Environmental Engineering Research Institute (NEERI) and the Laxminarayan Institute of Technology (LIT), used the solid state fermentation process to produce cellulose by using water hyacinth as the substrate.
The scientists include S K Deshpande, S S Godbole, Tapan Chakrabarti and Purshottam Khanna of NEERI and M G Bhotmange and Dr P N Shastri of LIT. A technical paper, describing the process, was presented recently at the national seminar on industrial waste treatment organised by LIT here.
Cellulose finds applications in number of industries like food, brewing, wine, paper and pulp, feed, textiles and others. It also acts as a cellulose saccharifying agent to produce fuel and chemicals. However, the high cost of enzyme production hashindered its wider industrial applications.
One of the factor contributing to the high production cost is the price of commercially available cellulose substrates. The pure substrates such as cotton and solka floc, used for the production of commercial cellulose, contribute to about 50 per cent of the production cost.
Water hyacinth is available in abundance and is seen as one of the most problematic weeds all over the world. The weed doubles in only eight to ten days and is thus abundantly available at no cost. The use of no-cost substrate for cellulose production can help in achieving the twin objectives of nuisance weed eradication and enzyme cost reduction.
Apart from cellulose, the process which makes use of the micro-organism Trichoderma Reesei for fermentation also leads to the production of another useful enzyme, Xynalase. This enzyme finds applications in the paper industry, upgrading of animal feed stuff and the clarification of fruit juice and wine.
The water hyacinth residue after enzymeproduction showed the potential to serve as fertiliser and soil conditioner because of its high nitrogen and nutrient content.
It can also be used as biocontrol agent as Trichoderma produces a large number of antibiotics and enzymes which are highly toxic to certain plant pathogens (disease producing organisms).
To produce the enzyme using water hyacinth as the substrate, the shoot part of the plant was chopped off, dried and pulverised to fine size. The dried substrate was then mixed with liquid nutrient (Toyoma Ogawa). This preparation was then inoculated with the Trichoderma Reesei strain and incubated for ten days for the enzyme to grow. The cellulose was extracted by percolation with saline.
In the pilot scale production undertaken by the research group, 105 litres of crude enzyme extract and 39 kg of residue was obtained using 250 kg of water hyacinth.
The pilot scale experimentation also established that the nuisance weed can be handled on a commercial scale for cellulose production in a cost-effective and environment-friendly manner.
Copyright © 1999 Indian Express Newspapers (Bombay) Ltd.