BackgroundNon-productive cellulase adsorption onto lignin has always been deemed to negatively affect the enzymatic hydrolysis of lignocellulosic feedstocks. Therefore, understanding enzyme-lignin interactions is essential for the development of enzyme mixtures, the processes of lignocellulose hydrolysis, and the genetic modification of lignocellulosic biomass and enzymes. In this work, we examined the properties of six lignins from diverse types of lignocellulosic biomass (aspen, pine, corn stover, kenaf, and two Arabidopsis lines, wild-type and SALK mutant of fah1) to determine the mechanism of differences in their adsorption of enzymes.ResultsWe found that lignin sources affected enzyme adsorption using structural features, such as functional groups and lignin composition. Guaiacyl (G) lignin had a higher adsorption capacity on enzymes than syringyl (S) lignin. The low S/G ratio and high uniform lignin fragment size had good correlations with high adsorption capacity. A higher content of phenolic hydroxyl groups and a lower content of carboxylic acid groups resulted in stronger adsorption affinity for corn stover lignin (CL) than for kenaf lignin (KL) and aspen lignin (AL). The lower amount of aliphatic hydroxyls that reduced hydrophobic interactions could explain the higher adsorption capacity of pine lignin (PL) than CL. Enzyme activity assays, as well as the hydrolysis of Avicel, phosphoric acid-swollen cellulose (PASC), and holocellulose, were performed to study the behaviors of mono-component enzymes that resulted in adsorption. We found that cellobiohydrolase (CBH) and xylanase were adsorbed the most by all lignins, endoglucanase (EG) showed less inhibition, and β-glucosidase (BG) was the least affected by lignins, indicating the important role of carbohydrate-binding module (CBM) in protein adsorption.ConclusionLignin sources affect enzyme adsorption using structural features and lignin composition, such as S/G ratio, carboxylic acid, aliphatic hydroxyl, and phenolic hydroxyl. For mono-component enzymes, the adsorption capacity decreased in the order CBH, xylanase > EG > BG. These investigations revealed the difference in lignin properties between diverse biomass and adsorption capacity of enzymes to lignins, and the possible underlying mechanism. The results can also serve as a reference for the genetic modification of lignocellulosic biomass and enzymes.

1Àx)(Bi 0.5 Na 0.5 )TiO 3 -xBa(Zr 0.055 Ti 0.945 )O 3 (0 x 0.12) lead-free ceramics have been prepared and the morphotropic phase boundary (MPB) is confirmed to be x ¼ 0.06-0.09. The MPB composition x ¼ 0.07 shows enhanced pyroelectric properties from room temperature (RT) to the depolarization temperature T d (87 C), with the pyroelectric coefficient p ¼ 0.057 lC/cm 2 C and the figures of merit F i ¼ 203 pm/V, F v ¼ 0.022 m 2 /C, and F d ¼ 10.5 lPa À1/2 at RT and the highest pyroelectric coefficient of 2.21 lC/cm 2 C near T d . These values are superior to other lead-based/lead-free pyroelectric ceramics. Enhanced pyroelectric properties can be explained by the effects of MPB and ferroelectric-antiferroelectric phase transition. V C 2013 AIP Publishing LLC.

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Oxide crystals have been widely used in nonlinear optics (NLO) in the ultraviolet-visible and near-infrared regions.M ost traditional oxide crystals are restricted to the mid-infrared region due to their narrowtransmission window. Hence,a ttempting to extend infrared cutoff wavelength of oxides has attracted muchattention. Herein, we report two new tellurates Li 2 TiTeO 6 (LTT) and Li 2 SnTeO 6 (LST) with broad transparent regions of 0.38-6.72 and 0.38-6.86 mm, respectively,asexcellent candidates for mid-infrared NLO applications. Both LTTa nd LST crystallizei nt he orthorhombic space group Pnn2. The LTTcrystal exhibits intense powder secondorder generation efficiency (26 KDP) under the fundamental wavelength of 1064 nm. First-principles calculations and dipole moments were used to illustrate the results of the powder second-harmonic generations based on the crystal structures. Our results provide an ovel oxide NLO crystal with as trong SHG and wide transparency range.T hey also pave aw ay for the design of new oxide mid-IR NLO crystals.

Reduced graphene oxide aerogel (RGOA) is synthesized successfully through a simultaneous self-assembly and reduction process using hypophosphorous acid and I2 as reductant. Nitrogen sorption analysis shows that the Brunauer-Emmett-Teller surface area of RGOA could reach as high as 830 m2 g−1, which is the largest value ever reported for graphene-based aerogels obtained through the simultaneous self-assembly and reduction strategy. The as-prepared RGOA is characterized by a variety of means such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Electrochemical tests show that RGOA exhibits a high-rate supercapacitive performance in aqueous electrolytes. The specific capacitance of RGOA is calculated to be 211.8 and 278.6 F g−1 in KOH and H2SO4 electrolytes, respectively. The perfect supercapacitive performance of RGOA is ascribed to its three-dimensional structure and the existence of oxygen-containing groups.