Ecofriendly unsing Biotechnology in Paper Industry

Paper are the product that produce in most massive number. In common technology production of paper ussually using a wood. Manufacture of paper from wood involves :

1. wood processing,
2. pulping,
3. bleaching and
4. sheet formation.

Pulping of wood (preferably from softwood with 3 - 5 mm long fibres, but rarely from hardwood with 1.5 mm long fibres) requires separation of the wood fibres from each other, which are then reformed into a sheet.
The wood fibres are glued together with the help of lignin and separation of these fibres is described as chemical pulping, when lignin is removed by degradation and is described as mechanical pulping, when fibres are mechanically teared apart. Both these methods of pulping are used.

Mechnical pulping gives higher yields and is cheap, but the quality of paper produced is relatively poor, turning yellow on exposure to sunlight. Further, the mechanical pulping requires lot of electrical energy. These difficulties can be overcome through the use of biotechnology.

The chemical pulp is also subjected to bleaching, in order to remove residual lignin leading to satisfactory increase in the brightness of paper. This bleaching step creates numerous toxic derivatives of lignin that constitutes environment hazard.

Using Biochemical Pulping 

In a recent report it was shown that a treatment of aspen chips (aspen is a wood; wood is received by pulp mills in two forms, logs or chips, the latter being more popular) with Phanerochaete chrysosporium before craft pulping (sulphate process) gives improved tensile strength (resistance to rupture by a force parallel to sheet) and burst strength (resistance to rupture by force perpendicular to sheet), but decreased tear strength (resistance to elongation under transverse shear), brightness and yield.

Brightness may be improved later by bleaching. More research and experimentation is needed before biochemical pulping becomes a reality and used in paper industry.

Using Biological Lignin Degradation 

In the pulping process, degradation of lignin can be achieved through treatment with microbes, of which lignolytic fungi are the most important. A biological step can be integrated, in pulping process, both in chemical pulping as well as in mechanical pulping. Three ways have been suggested for this purpose.
It may be seen that the biological step may be a pre treatment or a post de filtration, to remove lignin. However, the use of a biological step in lignin degradation is still at the level of research and experimentation.
Its use at industrial scale is seen as a distinct possibility due to successful results already obtained in several experiments. To support research in this area, a Biopulping Consortium (funded by 20 companies), was established in USA in 1987.