Study on the mechanism of lignin non-productive adsorption on cellobiohydrolase.

Enzymatic hydrolysis is important for lignocellulosic biomass conversion into fermentable sugars. However, the nonproductive adsorption of enzyme on lignin was major hinderance for the enzymatic hydrolysis efficiency. In this study, non-productive adsorption mechanism of cellulase component cellobiohydrolase (CBH) onto lignin was specific investigated. Research revealed that the adsorption behavior of CBH on eucalyptus alkali lignin (EuA) was affected by reaction conditions. As study on the adsorption kinetic, it was indicated that the adsorption cellulose binding domain (CBD) of CBH onto EuA well fitted with Langmuir adsorption model and pseudo second-order adsorption kinetics model. And the tyrosine site related to the adsorption of CBD onto lignin was proved by the fluorescence and UV spectra analysis. The results of this work provide a theoretical guidance to understanding the nonproductive adsorption mechanism and building method to reduce the adsorption of cellulase on the lignin.

Benefits of collaborative remembering in older and younger couples: the role of conversation dynamics and gender.

We experimentally explored whether and how conversation dynamics would benefit collaborative remembering in intimate couples over time. To this end, we ran a study with a three-factor mixed design with relationship type (couples vs. strangers) and age (older adults vs. younger adults) as between-participants variables, and remembering condition (collaborative vs. individual) as a within-participants variable. Thirty pairs of intimate couples (fifteen long-term relationship older couples, fifteen short-term relationship younger couples) and thirty pairs of corresponding stranger-pairs (including older strangers and younger strangers) were compared with respect to recall accuracy and conversation dynamics, specifically considering the role of gender. Results revealed significant collaborative facilitation only in older couples. Also, females' communication behaviours facilitated males' collaborative remembering performance only in older (vs. younger) couples. In addition, a gender-specific pattern of shifts from the individual to collaborative context emerged only in older couple (vs. strangers). The findings are consistent with the notion that a longer experience of collaboration and more effective conversation dynamics allow older (vs. younger) couples to perform better at collaborative remembering. We discuss processes underlying the observed gender differences, and the social and motivational implications of collaborative remembering.

Study on the chemical modification of alkali lignin towards for cellulase adsorbent application.

The research of cost-efficient lignin-based adsorbents is a practical strategy for the recovery of cellulase. In this study, alkali lignin was modified to increase the phenolic hydroxyl (Ph-OH) content for cellulase adsorption applications. After phenolation, compared with the lignin reference, the maximum adsorption cellulase capacity of lignoresorcinol (LigR) and lignopyrogallol (LigP) was improved from 76.5 mg/g to 842.1 mg/g and 911.4 mg/g, respectively. The enzyme activity of the adsorbed cellulase on LigR was higher than that on LigP, which could migrate to the fresh substrates during enzymatic hydrolysis. The adsorbed cellulase could be easily recovered from two lignin-based adsorbents by adjusting pH. The distinct cellulase adsorption behavior of two lignin-based adsorbents was closely related to the high Ph-OH contents and low S/G ratio in phenolated lignin samples characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Heteronuclear Single Quantum Coherence-Nuclear Magnetic Resonance (HSQC-NMR).