Research Interests: Chemistry, Medicine, Multidisciplinary, Environmental Biotechnology, Straw, and 15 moreStreptomyces, Raw materials, Raw Material, Laccase, Fermentation, Pulp and Paper Industry, Biological treatment, Bioreactors, Indexation, Sodium Hydroxide, Materials Testing, Tensile Strength, Triticum, Paper, and Bioresource technology
Additional file 5. Obtained films from cellulase control Ck (a) and Cmix (b) pretreatments after mechanical fibrillation.
Additional file 4. Z potential values of the samples obtained after mechanical fibrillation. R (initial refined pulp), Ck (control treatment), C9 (Cel9B), Cmix (cellulase mixture consisting in Fibercare and Celluclast), S (LPMO), SCmix... more
Additional file 4. Z potential values of the samples obtained after mechanical fibrillation. R (initial refined pulp), Ck (control treatment), C9 (Cel9B), Cmix (cellulase mixture consisting in Fibercare and Celluclast), S (LPMO), SCmix (LPMO and Cmix) and L_Tempo (Laccase_Tempo treatment).
Additional file 3. FTIR spectra of obtained films from control treatment (Ck) and Laccase_Tempo treatment (L_Tempo). TCI was calculated from the ratio of the absorptions at 1372 and 2900 cm−1. The peak detected at 1750 cm−1 with L_Tempo... more
Additional file 3. FTIR spectra of obtained films from control treatment (Ck) and Laccase_Tempo treatment (L_Tempo). TCI was calculated from the ratio of the absorptions at 1372 and 2900 cm−1. The peak detected at 1750 cm−1 with L_Tempo correspond to the COOH groups.
Additional file 2. Effect of the hydrolytic (a) and oxidative and Cmix (b) enzymatic pretreatments on fibre length distribution. The confidence interval of the length fibre distribution was less than 2% in all cases.
Additional file 1. TLC analysis of sugars released during enzymatic treatments performed at 50 °C, pH 5, during 18 h with 10 U g−1 odp of enzyme (in the case of Cmix the enzymatic dose was 20 U g−1 odp). C9 (Cel9B), C50 (Sertec20... more
Additional file 1. TLC analysis of sugars released during enzymatic treatments performed at 50 °C, pH 5, during 18 h with 10 U g−1 odp of enzyme (in the case of Cmix the enzymatic dose was 20 U g−1 odp). C9 (Cel9B), C50 (Sertec20 cellulase), CF (Fibercare cellulase), Cll (Celluclast cellulase), Cmix (cellulase mixture consisting in Fibercare and Celluclast). M) size markers of glucose (G), cellobiose (G2), cellotriose (G3), cellotetraose (G4) and cellopentaose (G5).
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Research Interests: Chemistry, Medicine, Multidisciplinary, Reaction Time, Laccase, and 15 moreEnzyme, Environmental Impact, Oxygen, Pulp and Paper Industry, Operant Conditioning, Enzyme activity, Effluent, Chemical Oxygen Demand, Paper Industry, Environment, Kraft Pulping, Paper, Bioresource technology, biobleaching, and coloring agents
Bleached cellulose with good end-properties (≈ 90% ISO brightness and 62% cellulose preservation) was obtained by using a totally chlorine-free biobleaching process (TCF). Unbleached sulphite cellulose was treated with Trametes villosa... more
Bleached cellulose with good end-properties (≈ 90% ISO brightness and 62% cellulose preservation) was obtained by using a totally chlorine-free biobleaching process (TCF). Unbleached sulphite cellulose was treated with Trametes villosa laccase in combination with violuric acid. This enzymatic stage (L) was followed by a chelating stage (Q) and then by a hydrogen peroxide stage reinforced with pressurized oxygen (Po), resulting to an overall LQPo sequence. The use of violuric acid was dictated by the results of a preliminary study, where the bleaching efficiency of various natural (syringaldehyde and p-coumaric acid) and synthetic mediators (violuric acid and 1-hydroxybenzotriazole) were assessed. The outstanding results obtained with laccase-violuric acid system fulfil most of the characteristics of commercial dissolving pulp, totally acceptable for viscose manufacturing or CMC derivatives, with the added advantage that the enzymatic treatment saved 2h of reaction time and about 70% of hydrogen peroxide consumption, relative to a conventional sequence (Po).
Research Interests: Chemistry, Biotechnology, Medicine, Multidisciplinary, Biocatalysis, and 15 moreCellulose, Bleaching, Color, Viscosity, Laccase, Hydrogen Peroxide, Bioprocess, Time Factors, Dissolving Pulp, Cellulose Fibers, Syringaldehyde, Biological Oxygen Demand Analysis, Paper, Bioresource technology, and biobleaching
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Research Interests: Business, Environmental Engineering, Cleaner Production, Sustainable Development, Packaging, and 11 moreEnvironmental Impact Assessment, Medicine, Production economics, Manufacturing Engineering, Circular Economy, Interdisciplinary Engineering, Sustainability, E Commerce, Electronic Commerce, Economia Circular, and Cellulose based materials
Research Interests: Business, Environmental Engineering, Cleaner Production, Sustainable Development, Packaging, and 11 moreEnvironmental Impact Assessment, Medicine, Production economics, Manufacturing Engineering, Circular Economy, Interdisciplinary Engineering, Sustainability, E Commerce, Electronic Commerce, Economia Circular, and Cellulose based materials
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An oxygen delignified eucalyptus Kraft pulp was bleached in a totally chlorine-free (TCF) sequence using an ozone stage (Z) followed by a hydrogen peroxide stage (P). Ozone treatments were carried out at a laboratory scale with new... more
An oxygen delignified eucalyptus Kraft pulp was bleached in a totally chlorine-free (TCF) sequence using an ozone stage (Z) followed by a hydrogen peroxide stage (P). Ozone treatments were carried out at a laboratory scale with new automated equipment. The Z stage was modeled using a four-variable sequential statistical plan over the following ranges: 10–20 g o.d.p. mass pulp, 20–50
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Ozone appears to be an effective choice for developing new totally chlorine free (TCF) sequences. One of the goals of current research into the use of ozone as a pulp-bleaching agent is to increase the selectivity of the process. In this... more
Ozone appears to be an effective choice for developing new totally chlorine free (TCF) sequences. One of the goals of current research into the use of ozone as a pulp-bleaching agent is to increase the selectivity of the process. In this work, various reagents were used as additives in the ozone bleaching stage (Z) with a view to raising its selectivity. Overall 16 different reagents were used under variable conditions and various properties of the resulting pulp (Kappa number, viscosity and brightness), in addition to the Z stage selectivity and the P stage efficiency, were determined. Based on the results, the additives studied exert a favourable effect on the process (particularly oxalic acid). The performance of the reagents are analysed through the study of chain scission number (CS) in the cellulose chain.
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An oxygen delignified eucalyptus Kraft pulp was bleached in a totally chlorine-free (TCF) sequence using an ozone stage (Z) followed by a hydrogen peroxide stage (P). Ozone treatments were carried out at a laboratory scale with new... more
An oxygen delignified eucalyptus Kraft pulp was bleached in a totally chlorine-free (TCF) sequence using an ozone stage (Z) followed by a hydrogen peroxide stage (P). Ozone treatments were carried out at a laboratory scale with new automated equipment. The Z stage was modeled using a four-variable sequential statistical plan over the following ranges: 10–20 g o.d.p. mass pulp, 20–50
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ABSTRACT Environmental pressure has led the pulp and paper industry to develop new technologies with a view to reducing or suppressing the presence of various pollutants in effluents from bleaching plants. One of the choices for this... more
ABSTRACT Environmental pressure has led the pulp and paper industry to develop new technologies with a view to reducing or suppressing the presence of various pollutants in effluents from bleaching plants. One of the choices for this purpose is enzyme-based biotechnology (particularly that using xylanases). This paper deals with the effect of using a xylanase-based enzymatic pretreatment on the properties of the resulting pulp and effluents, the hexenuronic acid content in the pulp and the physical properties of paper obtained by refining it. The results were all highly favourable and promising.
This study demonstrates the potential of applying surface enzymatic treatments on finished paper sheets to improve their physical characteristics. Research studies have recently reported that is possible to internally size paper using... more
This study demonstrates the potential of applying surface enzymatic treatments on finished paper sheets to improve their physical characteristics. Research studies have recently reported that is possible to internally size paper using enzymatic treatments, applied in mass. In the present work an innovative method for achieving enzymatic surface sizing on finished paper sheets is presented. A commercial filter paper and handmade eucalyptus sheets were surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin since it acts as a dispersant, improving the homogeneous distribution of the LG along the paper sheet.
ABSTRACT An innovative method has been developed for the surface hydrophobisation of cellulose-based materials by coating it with a functionalised solution (FS), in which sonicated lauryl gallate (LG, dodecyl 3,4,5,-trihydroxybenzoate),... more
ABSTRACT An innovative method has been developed for the surface hydrophobisation of cellulose-based materials by coating it with a functionalised solution (FS), in which sonicated lauryl gallate (LG, dodecyl 3,4,5,-trihydroxybenzoate), sulfonated kraft lignin, and the enzyme laccase play a pivotal role. The rapid treatment with FS increases the hydrophobicity of cellulose sheets considerably. The FS retention on the paper surface was analysed as a function of refining and application of additives. The properties of the functionalised sheets were assessed by the water-drop test (WDT), and the surface free energy (SFE) was determined via contact angle (CA) measurements in a goniophotometer. WDT resulted in long absorption times of up to 4000 s and CA values were around 130°. Functionalised solution modification of eucalyptus paper sheets decreased SFE essentially from 55 mJ m-2 to 10 mJ m-2. ATR-FTIR suggested that FS was grafted onto the cellulosic sheets. The stability of FS and the control solutions were characterised by Z potential and light scattering measurements. The functionalised solution method is a one-step roll-to-roll process, which is easy to perform also in industrial application without additional investments. It has a potential to substitute the traditional hydrophobing processes.
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ABSTRACT Different enzymatic strategies were applied to improve lignin and hexenuronic acid (HexA) removal. Three laccases (L) with different redox potentials were applied in combination with 1-hydroxybenzotriazole or methyl syringate to... more
ABSTRACT Different enzymatic strategies were applied to improve lignin and hexenuronic acid (HexA) removal. Three laccases (L) with different redox potentials were applied in combination with 1-hydroxybenzotriazole or methyl syringate to softwood sulfite and hardwood kraft fibers. The enzymes with a high-redox potential from Pycnoporus cinnabarinus and Trametes villosa were found to be the most efficient. The bleaching efficiency was not significantly influenced by the presence or absence of HexA in the different types of lignocellulosic fibers. Subsequently, the lignin or HexA removal in the presence of different mediators was evaluated in eucalyptus fibers with the T. villosa laccase (TvL). Natural mediators removed only lignin, whereas the combinations of TvL with synthetic mediators removed both HexA and lignin. The mediator violuric acid (VA) was the most efficient as judged by the properties of fiber and effluent. A xylanase pretreatment stage was found to boost the access of the LVA system to HexA without affecting lignin in the pulp.
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Research Interests: Chemical Engineering, Modeling, Prediction, Regulation, Optimization, and 21 morePulp and Paper, Toxicity, Color, Chlorine dioxide, Factorial Design, Reaction Time, Laccase, Enzyme, Industrial Application, Mathematical Model, Waste Water, Operant Conditioning, Effluents, Reactor, Oxidation, Chemical Oxygen Demand, Process Parameters, Enzymatic Activity, Experimental Data, DCO, and Timing Optimization
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Laccases in combination with various chemical compounds have been tested with a view to obtain environmental friendly, high-value paper products from unbleached flax pulp, which is currently being assessed as a raw material for... more
Laccases in combination with various chemical compounds have been tested with a view to obtain environmental friendly, high-value paper products from unbleached flax pulp, which is currently being assessed as a raw material for biotechnological innovation. With the aim of better understanding the effects of violuric acid (VA) and p-coumaric acid (PCA) on flax pulp, changes in the chemical composition of the two major fiber types it contains were assessed. Following classification, the initial pulp was split into two fractions according to fiber size, namely: bast (long) fibers and core (short) fibers. Fiber size was found to significantly influence the properties of pulp and it response to various laccase treatments. The laccase-PCA treatment substantially increased kappa number (KN) and color in both fiber fractions, which suggests grafting of the phenolic compound onto fibers. On the other hand, the laccase-VA treatment produced long fibers with a low lignin content (KN = 1.3) and a high brightness (5% points higher than for the control fraction), which testifies to its bleaching efficiency. Both biotreatments produced long fibers containing highly crystalline cellulose and caused HexA removal from global and short fibers. On the other hand, the laccase treatments caused no morphological changes in the fibers, the integrity of which was largely preserved. As shown here, laccase acts as polymerization agent with PCA and as delignification agent with VA; also, the two enzymes systems act differently on bast and core fibers.
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A new biotechnological procedure using laccase in combination with a hydrophobic phenolic compound (lauryl gallate) for the hydrophobization of cellulose fibres and internal sizing of paper was developed. Cellulose fibres from hardwood... more
A new biotechnological procedure using laccase in combination with a hydrophobic phenolic compound (lauryl gallate) for the hydrophobization of cellulose fibres and internal sizing of paper was developed. Cellulose fibres from hardwood kraft pulp were incubated with laccase (Lac), in combination with lauryl gallate (LG). The Lac-LG treatment resulted in the internal sizing of paper, and also in significantly reduced water penetration in the handsheets and wettability of the paper surface. Paper was found not to be effectively rendered hydrophobic by LG alone. SEM images of the fibre network revealed the presence of the sizing agent: a product of the reaction between laccase and lauryl gallate. Binding of lauryl gallate to cellulose fibres was suggested by the increase in kappa number of the pulp and further confirmed by IR spectroscopy.
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A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination... more
A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination with lauryl gallate (LG) as hydrophobic compound. The efficiency of the method was increased by the use of a lignosulfonate as a natural dispersant to improve the surface distribution of LG on the paper, raise its hydrophobicity and help preserve the enzyme activity. No similar threefold effect from a single compound for the improvement of enzymatic treatments was previously reported. The influence of processing conditions including the LG dose, treatment time and temperature was also examined, resulting in further increased hydrophobicity. Efficient fiber bonding and chemical functionalization were confirmed by thorough washing and Soxhlet extraction of the paper. As shown here for the first time, enzyme treatments have the potential to improve the surface hydrophobicity of paper-based media.