Fungal enzymes on the production of whitelined chipboard: technological and economic implications.

The aim of this project is to improve the quality and
productivity of paper manufacturing by using fungal enzymes
in order to control and remove slime and pitch deposition.

Waste paper contributes, as a raw material, to the production of recycled paper. In the paper industry, the use of recycled paper has significantly increased during the past ten years. This is an effective way to reduce the utilization of the world's timber resource. For this reason, recycling has been given a high priority in pulp and paper research in many countries. However, usage of the recycled paper and the presence of liquid effluents result in problems in processing and end product quality. These problems include the deposition of 'pitch' and 'slime' and one of the greatest challenges in paper recycling is to overcome them. Pitch is a general term for the low molecular weight, oleophilic materials such as triglycerides, fatty acids, resin acids, sterols extracted from wood chips in neutral, non-polar, organic solvents. The presence of chemical compounds in mills can convert reactive wood ingredients into new compounds that may be more problematic than the original extractives. Regardless of environmentally-driven changes in pulping and bleaching technologies, the pitch problems remain with the usage of certain wood species and recycled paper both in mechanical and chemical pulping processes. Another problem is the formation and deposition of slime which also causes significant operational problems in paper machines. Slime is the deposit of microbial origin in paper mills. It is impractical to run a paper mill as a sterile system so a vast variety of microbes contaminate the mills and produce extracellular polysaccharides, many of which are not characterised. The main aim of this project is to utilise the potential of microorganisms for the production of enzymes to be used in closed systems instead of using chemicals which have a negative impact on waste treatment as well. The methodologies that will be employed to fulfil the aim of this project will include: 1) Techniques to identify components responsible for slime and pitch problems and the contribution of problematic compounds to the toxicity of the paper mill. A biochemical approach to the chemical fractionation and separation of organic residues is a direct method to identify the hazardous compounds in complex mixtures, etc. The general method will be based upon fractionation of the effluent components using High Performance Liquid Chromatography (HPLC) in parallel with the toxicity characterization of each fraction by rapid bioassays. Gas Chromatography (GC) and GC-MS (Gas Chromatography with Mass Spectrometry detection) analyses will be performed. 2) Techniques to select strains and associated relevant enzymes capable of removing pitch and slime constituents. Initially, selected strains of Ophiostoma piceae and Fusarium oxysporum will be used for the production of lipolitic enzymes, mainly lipases and esterases, for the treatment of pitch components in the mill's recycled water circuit. Penicillium lilonecum and Fusarium solani will be used for the production of dextranases to degrade polysaccharides, which are the main components for slime deposition. After the first stage of the study, different fungal strains (isolated and tested for their relevant and efficient enzyme production) will be employed to create a more efficient biological system for pitch and slime reduction. Enzyme purification and characterization will be performed. The procedures for enzyme purification from fungal strains will include ultrafiltration and different chromatographic techniques, such as low pressure ion exchange, molecular exclusion, FPLC, HPLC, SDS-PAGE, etc. will be used. 3) Techniques to investigate the physiology of the fungi and scale-up of the process for enzyme production. A range of experiments will be carried out on selected organisms to establish the optimal conditions for the growth and production of enzymes. Medium development studies will be carried out in shaken flasks. After a suitable medium has been found, fermentation runs will be implemented in stirred tank reactors from 10 to 20 l batch cultures: temperature, pH, DOT, stirrer speed. Different modes of fermentation will be employed to improve production. After the optimal media and other environmental conditions have been established at small scale, the fermentations will be scaled-up to pilot scale (75 l, stirred tank reactor). Fro scale-up, the establsihed procedures will be adopted. 4) Techniques to investigate enzymatic treatment of problematic compounds. Small samples of slime and pitch deposits will be treated with selected enzymes. Commercial enzymes such as Resinase from NOVO will be also be used for comparison. Factors affecting the efficacy of enzymes in slime and pitch reduction will be studied in shaken flasks, stirred tank reactors. The effect of shear, pH and temperature will be investigated in particular. The efficacy of different enzymes in the biodegradation of different problematic compounds will be studied under different environmental conditions. In order to perform the project tasks, a range of analytical techniques will be adapted to assay the samples taken from shaken flasks and fermenters. 5) Techniques to analyse and evaluate pitch and slime deposits with reference to conventional methods: use of chemical and biologically-treated samples. 6) Techniques to evaluate the quality of the produced white chipboard and the economic aspect using the method developed. Keywords: fungal enzymes, fermentation, biodegradation.
Project ID: 
2 484
Start date: 
Project Duration: 
Project costs: 
640 000.00€
Technological Area: 
Paper technology
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.