The chemical compositions of lignin, hemicellulose and cellulose are so far unascertained to various lignocellulose in respect to effect of cellulose enzymatic hydrolysis . The novel and environment-friendly gluconic acid (GA) pretreatment technology showed impressive results on the enzymatic hydrolysis of cellulose in various agricultural straws. However, only few of the main reasons or critical issues pertaining to this reaction are known. Therefore, the novel GA pretreatment was carried out to remove hemicellulose from the three representative waste straws under different conditions. Next, for the enzymatic hydrolysis of the residual cellulose fraction in the pretreated straws, some mathematical correlations have been investigated between enzyme accessibility, hemicellulose removal rate, and cellulose crystallinity index. Both linear and nonlinear models were compared using five-parameter logic curve, four-parameter logic curve, and Deming regression. Hemicellulose removal was logically ascribed to be the trigger for cellulose saccharification efficiency during GA pretreatment of these waste straws.
Enzyme immobilization in hierarchically porous metal–organic frameworks (HP–MOFs) has attracted extensive attention in biocatalysis and contaminant biodegradation. However, the small-dimension mesopores and micropores on the exterior of MOFs are incompatible with large-sized enzymes, thus limiting the further enhancement of mass transfer efficiency and enzyme accessibility. Herein, we encapsulated horseradish peroxidase (HRP) in highly ordered macro–micropore zeolitic imidazolate framework-8, in which the encapsulated enzyme not only fully preserved its catalytic activity, but also exhibited long-term stability, recyclability, low leakage, and resistance to chelating compounds. Through enzyme immobilization, we significantly enhanced the biodegradation process of hazardous dyes probably as a result of the pre-concentration of the dye reactant for the combination of enzymes and MOFs. This work shows the great potential of constructing highly functional biocatalysts in three-dimensional ordered macro–micropore MOFs with enhanced mass diffusion efficiency, which is promising for applications to biodegradation of all sorts of other organic pollutants in water resources.
危险品化学品经营许可证（带存储）