Inhomogeneous lignin from a canola (rapeseed) straw was isolated and valorized as regularly shaped spherical microparticles for drug delivery formulations. Lignin with a purity of 83% and broad molecular weight distribution (<SIC> > 5.0) was extracted by alkali pulping and acetylated to increase spheronization ability. Lignins with high degrees of acetylation (0.76 and 0.89) were successfully assembled into microparticles with uniform sizes (approximately 2 mu m) and smooth spherical surfaces via solvent-antisolvent precipitation. Hydrophobic coumarin 153 and positively charged ciprofloxacin were used as model drugs to assess the encapsulation and release performance of lignin microparticles. Highly acetylated lignin microparticles displayed encapsulation efficiencies of 89.6% for coumarin 153% and 90.6% for ciprofloxacin. Scanning electron microscope images showed that coumarin 153 was encapsulated in the hydrophobic core, while ciprofloxacin was adsorbed on the less hydrophobic shell. The synthesis of lignin microcarriers not only provides a facile approach to utilizing waste canola straw lignin for drug delivery matrices but also has the potential to serve as an alternative lignin powder feedstock for bio-based materials.

Agricultural fiber sources, such as wheat straw, are promising lignocellulosic feedstocks for the generation of renewable substitutes for synthetic materials (e.g., plastics, construction materials, biofuel, and other biorefinery products). The interest in the utilization of lignin has increased rapidly during the last years; the number of publications increased more than five times between 2000 and 2020. The number of publications concerning lignin from wheat straw follows the general trend with an increasing scientific interest in lignin but comprises less than 5% of the total lignin publications. The structure and morphology of lignin in straw and wood differ between the different species. The monolignol composition and spatial location in plant tissue are notably different, as well as the nature and abundance of lignin-carbohydrate linkages involving p-coumaric acid (pCA) and ferulic acid (FA) units in wheat straw lignin. To further enable the utilization of wheat straw as a resource for bio-based materials, a solid understanding of the wheat lignin structure and composition is required. This review aims to consolidate the state-of-the-art in wheat lignin and focuses on lignin and its distribution, fundamental chemical structures, and morphology in wheat straw and compares these features with lignin in wood cell walls.

Antibiotic pollution is becoming an increasingly serious threat in different regions of China. The distribution of antibiotics in water sources varies significantly in time and space, corresponding to the amount of antibiotics used locally. The main source of this contamination in the aquatic environment is wastewater from antibiotic manufacturers, large scale animal farming, and hospitals. In response to the excessive antibiotic contamination in the water environment globally, environmentally friendly alternatives to antibiotics are being developed to reduce their use. Furthermore, researchers have developed various antibiotic treatment techniques for the degradation of antibiotics, such as physical adsorption, chemical oxidation, photodegradation, and biodegradation. Among them, biodegradation is receiving increasing attention because of its low cost, ease of operation, and lack of secondary pollution. Antibiotic degradation by enzymes could become the key strategy of management of antibiotics pollution in the environment in future. This review summarizes research on the distribution of antibiotics in China's aquatic environments and different techniques for the degradation of antibiotics. Special attention is paid to their degradation by various enzymes. The adverse effects of the pollutants and need for more effective monitoring and mitigating pollution are also highlighted.

In this study, we immobilized pectinase preparation on porous zeolite ZSM-5 as an enzyme carrier. We realized this immobilized enzyme catalyst, pectinase preparation@ZSM-5, via a simple combined strategy involving the van der Waals adsorption of pectinase preparation followed by crosslinking of the adsorbed pectinase preparation with glutaraldehyde over ZSM-5. Conformal pectinase preparation coverage of various ZSM-5 supports was achieved for the as-prepared pectinase preparation@ZSM-5. The porous pectinase preparation@ZSM-5 catalyst exhibited ultra-efficient biocatalytic activity for hydrolyzing the beta-glycosidic bonds in the model substrate 4-nitrophenyl beta-D-glucopyranoside, with a broad operating temperature range, high thermal stability, and excellent reusability. The relative activity of pectinase preparation@ZSM-5 at a high temperature (70 degrees C) was nine times higher than that of free pectinase preparation. Using thermal inactivation kinetic analysis based on the Arrhenius law, pectinase preparation@ZSM-5 showed higher activation energy for denaturation (315 kJ mol(-1)) and a longer half-life (62 min(-1)) than free pectinase preparation. Moreover, a Michaelis-Menten enzyme kinetic analysis indicated a higher maximal reaction velocity for pectinase preparation@ZSM-5 (0.22 mu mol mg(-1) min(-1)). This enhanced reactivity was attributed to the microstructure of the immobilized pectinase preparation@ZSM-5, which offered a heterogeneous reaction system that decreased the substrate-pectinase preparation binding affinity and modulated the kinetic characteristics of the enzyme. Additionally, pectinase preparation@ZSM-5 showed the best ethanol tolerance among all the reported pectinase preparation-immobilized catalysts, and an activity 247% higher than that of free pectinase preparation at a 10% (v/v) ethanol concentration was measured. Furthermore, pectinase preparation@ZSM-5 exhibited potential for practical engineering applications, promoting the hydrolysis of beta-glycosidic bonds in baicalin to convert it into baicalein. This was achieved with a 98% conversion rate, i.e., 320% higher than that of the free enzyme.

We here report a liquid-phase exfoliation strategy to delaminate multilayered biochars into multi-heteroatom (Fe, N, S) co-doped graphene-like carbon nanosheets, in which the multilayered biochars derived from naturally evolved layer-by-layer precursors. This strategy provides the versatile capability to tailor the textural properties of the as-synthesized carbon nanosheets, such as obtaining a controllable specific surface area of up to 2491 m2 g−1. Thanks to the unique integration of graphene-like microstructures with a thickness of 4.3 nm, large specific surface area and hierarchical pores, homogenous co-doping of N, S, and Fe, and high electronic conductivity, the as-synthesized Fe-N-S co-doped carbon nanosheets could act as multifunctional electrodes for electrocatalytic process of oxygen reduction reaction (ORR) and capacitive energy storage. The optimized nanosheets showed a better ORR catalytic performance than commercial Pt/C catalyst, with a more positive onset potential (1.026 V) and half-wave potential (0.829 V), higher long-term stability, and outstanding methanol tolerance in alkaline mediums. Furthermore, the porous carbon nanosheets exhibited excellent supercapacitive performances which delivered a high energy density of 29.1 Wh kg−1 at a high power density of up to 39.5 kW kg−1 in an ionic liquid electrolyte. This liquid-phase exfoliation strategy will offer new inspiration for the synthesis of various biomass-derived graphene-like carbon nanosheets for multifunctional applications.

Lignin extracted from trees is one of the most abundant biopolymers on Earth. Quinone, a sub-structure in lignin, can be used for energy storage via reversible redox reactions through absorbing and releasing electrons and protons. However, these efforts have encountered hindrances, such as short life cycle, low cycling efficiency, and a high self-discharge rate. All of these issues are related to electrode dissolution by electrolyte solvents and the insulating nature of lignin. Addressing these critical challenges, for the first time we use a reconfigurable and hierarchical graphene cage to capture the lignin by mimicking the prey-trapping of venus flytraps. The reconfigurable graphene confines the lignin within the electrode to prevent its dissolution, while acting as a three-dimensional current collector to provide efficient electron transport pathways during the electrochemical reactions. This bioinspired design enables the best cycling performance of lignin reported so far at 88% capacitance retention for 15000 cycles and 211 F g-1 capacitance at a current density of 1.0 A g-1. This study demonstrates a feasible and effective strategy for solving the long-term cycling difficulties of lignin-based electrochemically active species, and makes it possible to utilize lignin as an efficient, cheap, and renewable energy storage material.

The potential of organosolv and kraft eucalyptus and spruce lignin as feedstock for polymeric materials and biofuel applications was assessed. Proximate analysis was used to predict the heating values and char formation. Chemical modification, based on the esterification reaction with methacryloyl chloride, was applied to introduce vinyl groups into the lignin macromolecules for enhanced reactivity. Kraft eucalyptus and spruce lignins had a more condensed structure than organosolv lignins, which resulted in greater thermal stability for these lignins. For different species within the same process, the thermal parameters showed a correlation with certain structural and compositional parameters (ash and sugars content, molecular weight and degree of condensation). Organosolv spruce lignin produced the highest heating value of 24. MJ/Kg, which is suitable for biofuel applications. The content of phenolic OH groups was higher for kraft lignins and especially higher for softwood lignins, both organosolv and kraft. The degree of methacrylation, estimated from the content of vinyl groups per C9 lignin unit, was significantly greater for organosolv lignins than for kraft lignins despite the higher OH-groups content in the latter.

A protocol for the quantitative fractionation of lignin carbohydrate complexes (LCC) from wood under mild conditions has been developed. All operations occur at near-neutral pH conditions and low temperatures, in order to preserve the native structure. The protocol also achieved the fractionation of hemicelluloses of relatively high purity enabling for the first time estimates of hemicelluloses fractions not chemically bound to lignin in wood. 2D HSQC NMR was applied to decipher the structure of LCCs and was complemented by thioacidolysis-GC MS techniques. The carbohydrates linked to lignin in LCC are hemicelluloses, mainly arabinoglucuronoxylan (AGX) and galactoglucomannan (GGM). Benzylether (BE) and phenyl glycosidic (PG) linkages were detected. Significant structural differences in the lignin part of LCCs are also reported. The novelty of this work is that we report the first quantitative pH neutral protocol for LCC fractionation and detailed chemical analyses unveil important structural differences of relevance to fundamental knowledge in lignin polymerization and wood-based biorefineries.

In this study we were mirroring suggested in vivo phenomena of lignin-hemicellulose complex formation in vitro, by cross-linking Norway spruce (Picea abies) galactoglucomannans, xylans and lignin moieties to high molecular weight complexes by laccase treatment. We were able to observe the oxidation and cross-linking of non-condensed guaiacyl-type phenolic moieties attached to both of the hemicelluloses by P-31 NMR and size-exclusion chromatography. We suggest that hemicelluloses-lignin complexes form covalently linked structural units during the early stages of lignification via radical enzymatic cross-linking catalyzed by laccase. This work shows that the hemicellulose molecules in wood are covalently linked to two or more lignin units thereby making them suited for forming network structures.