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The growing environmental concerns and depletion of fossil fuels resulted in an increased interest in environmentally friendly materials based on natural polymers. Efforts are being made to introduce the lignin in plastic composites such as polypropylene, with the aim of producing bio-based materials with desirable mechanical characteristics. In this study, blends of lignin powder and polypropylene were extruded and testing samples were produced by injection molding process. The produced materials were tested for physical, mechanical and thermal properties. The results showed that the incorporation of the lignin powder in polypropylene matrix resulted in a composite with suitable property application for various industrial fields, especially those were mechanical features are crucial, such as the replacement of engineering plastics.

Non-productive adsorption of cellulases onto lignins is an important mechanism that negatively affects the enzymatic hydrolysis of lignocellulose biomass. Here, we examined the non-productive adsorption of two bacterial β-glucosidases (GH1 and GH3) on lignins. The results showed that β-glucosidases can adsorb to lignins through different mechanisms. GH1 β-glucosidase adsorption onto lignins was found to be strongly pH-dependent, suggesting that the adsorption is electrostatically modulated. For GH3 β-glucosidase, the results suggested that the fibronectin type III-like domain interacts with lignins through electrostatic and hydrophobic interactions that can partially, or completely, overcome repulsive electrostatic forces between the catalytic domain and lignins. Finally, the increase of temperature did not result in the increase of β-glucosidases adsorption, probably because there is no significant increase in hydrophobic regions in the β-glucosidases structures. The data provided here can be useful for biotechnological applications, especially in the field of plant structural polysaccharides conversion into bioenergy and bioproducts.

Known as the main source of aromatic compounds in nature, lignin possesses heterogeneous composition which has high potential to be used in many industrial purposes. Lignin has been used as retardants of fire, thermal stabilizer, hydrophobicity agent, carbon fiber, aerogels and antioxidants. This review summarizes several uses of lignin-based components and their potential applications. We focused on the industrial uses of lignin in order to diminish the dependence of petroleum-based materials.

The mycelial growth ability of 13 white rot fungi were separately evaluated in kraft, organosolv, and soda black liquor agar-plates. The fungus able to best grow and decolorize black liquor agar-plates was grown in organosolv black liquor to investigate whether it reduced organosolv lignin molar mass. The fungus Bjerkandera adusta showed fair mycelial growth and decolorization ability in 10% black liquor-agar plates. To obtain low-molecular weight (MW) lignin, B. adusta was cultivated in 150-mL Erlenmeyer flasks containing 10% black liquor and maintained in a shaking culture for 15 days. Lignin was recovered from each Erlenmeyer flask by acid precipitation and was analysed by size exclusion chromatography (SEC) and Fourier transform infrared (FTIR) spectroscopy. The lowest MW of lignin from black liquor was observed on the 11 th and 12 th days, at 1461 and 1790 kDa, respectively, with the polydispersity close to 1.0, indicating that the molecules were similar in size. Fourier transform infrared spectra bands showed modification of the lignin structure during 9 days, with new bands appearing after five days of lignin biodegradation.

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In this study, we aimed evaluate the behavior of the brown-rot fungus Gloeophylum trabeum and white-rot fungus Pycnoporus sanguineus on thermally-modified Eucalyptus grandis wood. To this end, boards from five-year-eleven-month-old E. grandis trees, taken from the Duratex-SA company stock, were thermally-modified between 180 °C and 220 °C in the Laboratory of Wood Drying and Preservation at Universidade Estadual Paulista -UNESP, Botucatu, Sao Paulo state Brazil. Samples of each treatment were tested according to the ASTM D-2017 (2008) technical norm. The accelerated decay caused by the brown-rot fungus G. trabeum was compared with the decay caused by the white-rot fungus P. sanguineus, studied by Calonego et al. (2010). The results showed that (1) brown-rot fungus caused greater decay than white-rot fungus; and (2) the increase in temperature from 180 to 220 °C caused reductions between 28.2% and 70.0% in the weight loss of E. grandis samples incubated with G. trabeum.

Wood plastic composites (WPC) are characterized by the mixing of wood fibers with plastics, allowing the production of new products whose characteristics are in several aspects superior to those of the original products and represent an expanding class of durable and low-cost materials in which their uses can reduce the environmental footprint and the dependence on petroleum products. Nevertheless, WPC has some setbacks, including biodegradation, which shortens its life span. In this study, the wood composite was exposed to the white-rot fungus Pycnoporus sanguineus in order to evaluate its resistance to biodegradation. The WPC was prepared with a 1:1 ratio of Eucalyptus spp. bark as reinforcement agent and polypropylene as matrix. Mechanical and rheological properties and mass loss were evaluated from 15 to 120 days of fungus exposure. After 15 days, a mass loss was detected, which transmitted a negligible effect on the impact resistance of the composite. For the 120-day fungus-exposed composite, the fungus produced a biofilm under the WPC that create a special environment for lignocellulosic consuming led to deterioration of the mechanical properties and minor changes on the thermal–chemical stability of the WPC. Finally, the study gave a great indication of the susceptibility of a Eucalyptus-based composite to biodegradation.