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The synthesis of poly[vinylamine-co-(sodium acrylate)] [P(VAm-co-NaAA)] and its application as a paper strength additive have been investigated. P(VAm-co-NaAA) was synthesized by the alkaline hydrolysis of poly[Nvinylformamide- co-(acrylic acid)] (PNVFAA). The influence of polymer concentration, hydrolysis temperature, and NaOH concentrations on the extent of hydrolysis were examined experimentally. The hydrolysis was 100% completed under the following conditions: hydrolysis temperature 80 °C, hydrolysis time 8 h, polymer concentration 2%, and NaOH concentration 0.045 mol/g of PNVFAA. P(VAm-co-NaAA) obtained in this manner increased the tensile strength and folding endurance of paper by 44% and 48%, respectively, and the strength increase was greater than that obtained with the commercially available polyvinylamine. [ABSTRACT FROM AUTHOR]

Biomaterials from olive tree pruning are an abundant agricultural residue in various Mediterranean regions. A suggested use of this residue is its separation in a main fraction (trunks and stems with diameter > 1 cm) and a residual fraction (leaves and stems with diameter 1 < cm), using biorefinery procedures. The main fraction is cooked with ethanol, giving rise to a pulp, which can be used either in paper or in bioethanol production if before pulping the main fraction is subjected to a hydrothermal treatment. Pulping with 70% ethanol concentration, 185 °C for 80 min resulted in a pulp with a yield of 46.30% and a content of holocellulose, α-cellulose, and lignin of 77.17%, 62.49%, and 21.73%, respectively. The paper sheets obtained had a breaking length of 1168 m, a burst index of 0.44 kN /g, a tear index of 2.25 mN.m²/g, and a brightness of 43.66%. The pulp converted into bioethanol (by simultaneous hydrolysis and fermentation) achieved a conversion of 70 g bioethanol/100 g potential bioethanol. The residual fraction of olive tree prunings was subjected to combustion to produce thermal energy. The heating value was 18700 kJ/kg, the flame temperature range was 1094 to 2013 ºC, and the dew point temperature range of the flue gases was 47 to 53 °C. [ABSTRACT FROM AUTHOR]

This study reports the regulation and purification of β-glucosidases from a thermotolerant Aspergillus terreus AN1 strain, previously reported for efficient deinking of composite paper waste. The differential expression of four β-glucosidase isoforms, in response to carbon sources in production medium, was studied by electrophoretically resolving proteins by polyacrylamide gel electrophoresis analysis (PAGE) and developing zymograms using methylum-belliferyl β-D glucoside as substrate. Three β-glucosidases (βGI, βGII & βGIII) were purified using chromatographic techniques. SDS-PAGE revealed the respective molecular masses of βGI, βGII, and βGIII, as 29, 43, and 98 KDa, and isoelectric point (pI) to be 2.8, 3.7, and 3.0. The β-glucosidases exhibited diverse pH and temperature optima as well as stability. β-Glucosidase I (βGI) specifically recognized pNP-β-glucopyranoside (pNPG) as a substrate, whereas, β-glucosidase II (βGII) and III (βGIII) also showed activities against cellobiose and salicin. In contrast to βGII and βGIII, the activity of βGI was positively influenced in the presence of hexoses/pentoses and alcohols. Km and Vmax for hydrolysis of pNPG by βGI, βGII, andβGIII were found to be 14.2 mM and 166.9 µmol -1mg protein -1, 4.37 mM, and 34.7 µmol -1mg proteins -1, and 11.1 mM and 378.7µ mol -1 mg protein -1, respectively. [ABSTRACT FROM AUTHOR]