scholarly journals Optimization of Laccase/Mediator System (LMS) Stage Applied in Fractionation of Eucalyptus globulus

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 731
Author(s):  
Javier M. Loaiza ◽  
Ascensión Alfaro ◽  
Francisco López ◽  
María T. García ◽  
Juan C. García
Keyword(s):  
Eucalyptus Globulus ◽  
Solid Phase ◽  
Liquid Fraction ◽  
Strength Properties ◽  
Raw Material ◽  
Eucalyptus Wood ◽  
Mediator System ◽  
Laccase Mediator System ◽  
Alkaline Delignification ◽  
Enzymatic Delignification

In a biorefinery framework, a laccase/mediator system treatment following autohydrolysis was carried out for eucalyptus wood prior to soda-anthraquinone pulping. The enzymatic and autohydrolysis conditions, with a view to maximizing the extraction of hemicelluloses while preserving the integrity of glucan, were optimized. Secondly, pulping of solid phase from Eucalyptus globulus wood autohydrolysis and the enzymatic process was carried out and compared with a conventional soda-anthraquinone (AQ) pulping process. The prehydrolysis and enzymatic delignification of the raw material prior to the delignification with soda- Anthraquinone (AQ) results in paper sheets with a lower kappa number and brightness and strength properties close to conventional soda-AQ paper and a liquid fraction rich in hemicellulose compounds that can be used in additional ways. The advantage of this biorefinery scheme is that it requires a lower concentration of chemical reagents, and lower operating times and temperature in the alkaline delignification stage, which represents an economic and environmental improvement over the conventional process.

scholarly journals Finger-jointing of green Eucalyptus globulus L. wood with one-component polyurethane adhesives

2021 ◽  
Author(s):  
Oscar González-Prieto ◽  
José Manuel Casas Mirás ◽  
Luis Ortiz Torres
Keyword(s):  
Eucalyptus Globulus ◽  
Bending Strength ◽  
Strength Properties ◽  
Raw Material ◽  
Green Wood ◽  
Finger Joints ◽  
Polyurethane Adhesives ◽  
Cold Setting ◽  
Finger Jointing ◽  
Glued Joints

AbstractThe use of glued finger joint in green wood, directly from the sawing process, would open the possibility to obtain glued timber from small-sized wood, achieving an efficient use of the original raw material. The gluing of finger-jointed green wood, with moisture content above the fibre saturation point, may improve the efficiency and the manufacturing process of glulam or joinery. This may be especially beneficial for a hardwood such as Eucalyptus globulus L., which is a globally important forest resource, but is a challenging wood to dry. This article presents a study on the possibility to develop finger joints with wood in green state. To compare them, conventional finger joints on dry wood and solid boards without end joints were also manufactured. Cold-setting and fast-curing commercial one-component polyurethane adhesive systems were used. Finger-jointed samples were tested to determine mean and characteristic values (5th percentile) of density, bending strength and modulus of elasticity, and the results were analysed and discussed. Green-glued joints showed no statistically significant differences compared to the solid boards and improved strength properties with respect to dry-glued joints.

scholarly journals Structure, Composition, and Thermal Properties of Cellulose Fibers from Pueraria lobata Treated with a Combination of Steam Explosion and Laccase Mediator System

BioResources ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. 6854-6866 ◽  
Author(s):  
Minghua Li ◽  
Guangting Han ◽  
Yan Song ◽  
Wei Jiang ◽  
Yuanming Zhang
Keyword(s):  
Steam Explosion ◽  
Lignin Content ◽  
Combined Treatment ◽  
Cellulose Fibers ◽  
Raw Material ◽  
Chemical Components ◽  
Cellulose Content ◽  
Pueraria Lobata ◽  
Mediator System ◽  
Laccase Mediator System

Cellulosic fibers from the bast of Pueraria lobata (P. lobata) vine were separated using a “green” and efficient method that combined steam explosion (SE) and a laccase mediator system (LMS). The chemical components, structure, and thermal alterations in the fibers were evaluated. The SE performed at 180 °C for 10 min did not change the chemical composition of P. lobata; however, SE did alter the fiber structure and rendered its surface more accessible to the laccase enzyme. Treated and untreated samples were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), and chemical methods. The cellulose content of the processed fibers was approximately 68.2%, and the lignin content was 11.8%, which was much lower than the 22.98% lignin content of the raw material. The cellulose fibers exhibited higher cellulose crystallinity and thermal stability compared with the untreated samples. This combined treatment approach may be useful for the isolation of cellulose fibers for composites, textiles, and other industrial applications.

scholarly journals Antioxidants Profiling of By-Products from Eucalyptus Greenboards Manufacture

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 263 ◽  
Author(s):  
Celeiro ◽  
Lamas ◽  
Arcas ◽  
Lores
Keyword(s):  
Mass Spectrometry ◽  
Bioactive Compounds ◽  
Solid Phase ◽  
Antioxidant Properties ◽  
Raw Material ◽  
Added Value ◽  
Gas Chromatography Mass Spectrometry ◽  
Eucalyptus Wood ◽  
Organic Extracts ◽  
By Products

Three different by-products from the Eucalyptus wood industry have been exhaustively characterized to find compounds with antioxidant properties. The industrial process to manufacture Eucalyptus greenboards is distinguished by using just wood and water, which converts the generated by-products in a highly attractive source of bioactive compounds that are originally in the raw material. The studied by-products were: the screw water, derived from the washing of the wood chips; the condensates, obtained after the evaporation and further condensation of the screw water; and finally, the concentrate of eucalyptus. For all of them and for their derived organic extracts, the total polyphenols content (TPC) and antioxidant activity (AA) have been evaluated. The chromatographic fingerprints, based on gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) have been obtained to identify the main extractable organic wood components. Besides, solid-phase microextraction (SPME) has been employed to characterize the most volatile compounds. Significant differences were observed for the chromatographic profiles of the studied by-products. Up to 48 and 30 different compounds were identified in the screw water, and condensate by-products, respectively; whereas the highest number of compounds, up to 72, have been identified in the organic extracts derived from the concentrate of Eucalyptus, highlighting the presence of monoterpenes, sesquiterpenes, polyphenols, and other bioactive compounds with antioxidant properties. Therefore, these by-products could be exploited to obtain natural extracts with added value which could be reused in the food, cosmetic or pharmaceutical industry, reducing the environmental impact of the industrial activity.

SYNTHESIS OF HYDROGEN IN ACOUSTOPLASMA DISCHARGE IN A LIQUID-PHASE STREAM

2019 ◽  
pp. 42-48 ◽  
Author(s):  
N. A. Bulychev
Keyword(s):  
Liquid Phase ◽  
Organic Compounds ◽  
Electrode Materials ◽  
Solid Phase ◽  
Plasma Discharge ◽  
Raw Material ◽  
Two Phase ◽  
Reduced Pressure ◽  
External Power Source ◽  
Phase Medium

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.

scholarly journals Effect of Fertilisation on the Quality of Dried Coriander (Coriandrum sativum L.) and Lovage (Levisticum officinale)

Agriculture ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 386
Author(s):  
Natalia Matłok ◽  
Józef Gorzelany ◽  
Adam Figiel ◽  
Maciej Balawejder
Keyword(s):  
Bioactive Compounds ◽  
Crop Production ◽  
Solid Phase ◽  
Quality Parameters ◽  
Raw Material ◽  
Vacuum Microwave ◽  
Dpph Method ◽  
Total Antioxidant ◽  
Total Antioxidant Potential

The study presents the effects of fertilisation on selected quality parameters of the dried material obtained from plants of lovage and coriander. During the crop production process, the plants were treated with two fertilisers containing substances potentially acting as elicitors. The dried material was obtained in course of a drying process carried out in optimum conditions and based on the CD-VMFD method which combines convective pre-drying (CD) at a low temperature (40 °C) with vacuum-microwave finish drying with the use of 240 W microwaves (VMFD). The quality of the dried material was evaluated through measurement of the total contents of polyphenols, total antioxidant potential (ABTS and DPPH method), and the profile of volatile compounds (headspace-solid phase microextractio-HS-SPME) as well as assessment of the colour. It was found that by applying first fertilisation (with organic components) it is possible to significantly increase the contents of both bioactive compounds and volatile substances responsible for the aroma. It was determined that the higher content of bioactive compounds was related to the composition of the first fertiliser, presumably the extract from common nettle. The study showed that the application of the first fertiliser contributed to enhanced quality parameters of the raw material obtained.

scholarly journals Efficient bleaching of non-wood high-quality paper pulp using laccase-mediator system

2004 ◽  
Vol 35 (2-3) ◽  
pp. 113-120 ◽  
Author(s):  
Susana Camarero ◽  
Olga Garcı́a ◽  
Teresa Vidal ◽  
José Colom ◽  
José C del Rı́o ◽  
...  
Keyword(s):  
Paper Pulp ◽  
High Quality ◽  
High Quality Paper ◽  
Mediator System ◽  
Laccase Mediator System

Effect of microbial isolates on microbial yield estimation in RUSITEC system

1998 ◽  
Vol 22 ◽  
pp. 306-308
Author(s):  
M. D. Carro ◽  
E. L. Miller
Keyword(s):  
Protein Synthesis ◽  
Liquid Phase ◽  
Solid Phase ◽  
Liquid Fraction ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Continuous Culture System ◽  
The One

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).

Sequential decolourization of reactive textile dyes by laccase mediator system

2009 ◽  
Vol 84 (3) ◽  
pp. 442-446 ◽  
Author(s):  
Ana P. M. Tavares ◽  
Raquel O. Cristóvão ◽  
José A. F. Gamelas ◽  
José M. Loureiro ◽  
Rui A. R. Boaventura ◽  
...  
Keyword(s):  
Textile Dyes ◽  
Mediator System ◽  
Laccase Mediator System

Fiber surface characterization of old newsprint pulp deinked by combining hemicellulase with laccase-mediator system

2011 ◽  
Vol 102 (11) ◽  
pp. 6536-6540 ◽  
Author(s):  
Q.H. Xu ◽  
Y.P. Wang ◽  
M.H. Qin ◽  
Y.J. Fu ◽  
Z.Q. Li ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Fiber Surface ◽  
Mediator System ◽  
Laccase Mediator System
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