eduardo cesarBy using biotechnological resources to alter some biochemical characteristics of the wood of the eucalyptus, researchers from the University of São Paulo (USP), in Piracicaba, are developing trees that in future are going to generate pulp and, afterwards, paper with a better quality. They have already obtained, in the laboratory, plants with genes of the Eucalyptus grandis species itself and from other plants that produce enzymes responsible for the biosynthesis of the hemicelluloses, a compound of the chemical group of the sugars, present between the cellulose fibers.
“The more hemicelluloses there are in the wood, the better the quality of the pulp will be, as it will become more resistant in the process of making the rolls of paper, without tearing and with more whiteness. With the end consumer, a paper with these characteristics should ensure a better quality of printing and also result in a material with more resistance and adaptability for the packaging sector”, explains Carlos Alberto Labate, a professor from USP’s Luiz de Queiroz College of Agriculture and the coordinator of the project being carried out in partnership with Suzano Papel e Celulose, one of the largest producers of pulp and paper in the country, with units in the states of São Paulo and Bahia.
The project was drawn up under the Partnership for Technological Innovation Program (PITE), which receives financing both from FAPESP and from the company. The group of 27 researchers, including ten from the company with technical qualification scholarships, initially managed to superexpress genes responsible for the biosynthesis of the hemicelluloses in the genetic code (DNA) of tobacco (Nicotiana tabacum), a model plant for this kind of experiment. Afterwards, it was the turn of specimens of the eucalyptus itself, turning them into transgenic plants. Some of the genes introduced into the two plants, found in world genome banks, came from plants like soybeans, potatoes, peas and from another model plant, Arabidopsis.
Amongst the possibilities analyzed for using and expressing the various genes, two of them proved to be more interesting, the one with the name of ugdh (also found in eucalyptus) was the champion in the production of xylans, a kind of hemicellulose, in three transgenic lineages of tobacco. Another important factor in some plants was the increase in soluble lignin, a kind of vegetable polymer that works like a cement between the hemicelluloses and the cellulose fibers. More soluble lignin implies less spending on chemical compounds in the process of whitening the paper in the factory. Accordingly, the lower quantity of lignin may lead to an increase in the yield in the manufacture of white paper.
Approval and patent
The next step in the experiment is to test the plants in the field and to wait four or five years for the eucalyptus to be transformed into a tree and to demonstrate the viability of the experiment. For this, the researchers will have to request approval of the planting in the field by the National Biosafety Technical Commission (CTNBio). In the meantime, the researchers and the companies have deposited in Brazil, at the National Institute of Industrial Property (INPI), and, abroad, the patent for the process developed by them to obtain the metabolic route that increases the production of the hemicelluloses with the intention of improving the quality of the wood.
Labate believes that the confirmation of the new technology for the productive sector is still going to take a while, and in the meantime he is finalizing some papers for publication in scientific magazines. For the company, it is a bet on the future. “Our prospect is for us to have differentiated raw material and end products also differentiated, with variability, in a few years”, foresees agronomist engineer Shinitiro Oda, responsible for Suzano’s plant biotechnology area. “Few companies are working with hemicellulose nowadays, the researches are more aimed at cellulose and lignin”, he says. Oda notes that, besides scientific and technological development, one of the important factors in the project is the training of professionals for the area. In all, the project finalized in September this year under the auspices of the Pite and that continues with the support of Suzano has collaborated towards one master’s thesis and four doctor’s theses, besides several scientific initiation papers. The project also could count on four postdoctoral students.
The interest for biotechnology in the area of pulp and paper can be measured by the project known as Forests, the consortium for sequencing the genome of the eucalyptus – started in 2001 and finalized in 2004 – made up of four companies from the sector: Suzano, Votorantim, Duratex and Ripasa, a company bought by Suzano and Votorantim in 2005. Labate, who also took part in this project, believes in new prospects for wood from eucalyptus. “The study of the proteins that form the wood of the eucalyptus, together with the knowledge of new genes, may result in the use of this tree as raw material in the production of alcohol (ethanol) and of biopolymers”, he believes.
Companies from North America and from Europe are interested in these products. To produce these biopolymers, which are biodegradable, like plastics, for example, and have a great environmental appeal, more cellulose and more hemicellulose in the raw material is needed, from the wood of any tree. Accordingly, the researches carried out at Piracicaba, initially for the production of pulp and paper, have great future prospects, even to the point of replacing or containing the production of petroleum.
Alteration of the quality of the wood of the eucalyptus (nº 01/11080-8); Modality Partnership for Technological Innovation Program (PITE); Coordinator Carlos Alberto Labate – USP; Investment R$ 242,216.00, US$ 925,350.62 (FAPESP) and R$ 937,141.15 (Suzano Papel e Celulose)