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The industrial application of free enzyme is limited due to its high cost, poor operational stability and difficult reuse. Immobilization on carrier is an effective way to overcome the limitation. Nanozyme immobilization technology has emerged in the past 10 years, which is an emerging technology with great potential. At present, immobilized enzymes have been widely used in several fields such as food, medical treatment, and environmental treatment. This article systematically summarizes the latest progress in the research and application of immobilized enzymes based on three new nanomaterials (protein-inorganic hybrid nanoflowers, metal organic frameworks and nanogels), comprehensively compares the advantages and disadvantages of the three nanomaterials, analyzes and summarizes their respective applicable enzymes, and finally points out that cascade enzyme immobilization and the development of new immobilized materials are the future trend for the development of immobilized enzymes.

From the perspective of a circular economy, the bioconversion of methane into valuable protein and carbohydrates can provide alternative food resources, while reducing greenhouse gas emissions. In this study, a nutritional induction strategy for artificial biomanufacturing by an industrial-promising methanotrophic bacterium was proposed for the first time. Three different scenarios of methanotrophic cultivations were carried out by manipulating the availability of oxygen and nitrogen during fermentation to investigate the flexible and efficient biosynthesis of cell proteins, glycogen, and extracellular polysaccharides (EPS). The highest titer of glycogen (5.21 g L−1) and EPS (15.81 g L−1) was observed in scenario I and scenario II, respectively. However, the maximum cell protein productivity (640.05 mg L−1 h−1) was achieved in scenario III with nutrimental balance, resulting in a 2.1-fold enhancement compared to scenario I under nutrient depletion. Further transcriptomic analysis revealed the nutritional induction mechanism, with central carbon and nitrogen metabolisms being boosted with sufficient key nutrients in scenario III, leading to the significant up-regulation of related genes towards protein synthesis. Additionally, a preliminary economic and environmental assessment highlighted the potential benefits of methane-based biomanufacturing in reducing production expenses and greenhouse gas emissions, which may help drive innovation and the development of sustainable and environmentally friendly products. [ABSTRACT FROM AUTHOR]

Enzymatic catalysis is of great importance due to its high catalytic activity and high selectivity. However, intrinsic fragile property of enzyme limits its application in a wide range, where inactive inorganic materials have proven promising in enhancing the stability of the enzyme in industry. Here, Prussian blue nanoparticles (PB) as peroxidase mimics were adopted for encapsulation of peroxidase, Cytochrome c (Cyt c). Prussian blue/Cytochrome c (PB@Cyt c) composite developed via in‐situ assembly exhibited a 2.6‐fold higher apparent enzymatic activity than the sum activity of equivalent Cyt c and PB due to synergistic effect. Mechanism investigation showed that interaction between irons ions from PB and carbonyl group and nitrogen from enzyme led to a favorable catalytic conformation of Cyt c. Moreover, PB shielded the encapsulated Cyt c against harsh conditions (e. g. high temperature and organic solvents). This new efficient hybrid catalyst would open opportunities for wide applications in biosensors and biocatalysis. [ABSTRACT FROM AUTHOR]

Two novel polysaccharides DOP1-DES and DOP2-DES with molecular weight of 297,911 Da and 30,400 Da were extracted by using DESs from Dendrobium officinale for the first time, and purified with macroporous resin AB-8, Sephadex G75 and Sephadex G200 chromatography. Besides, the effect of extraction temperature, molar ratio of DES, reaction time and compound enzymes concentration on the extraction yield of polysaccharides were investigated. Monosaccharide composition analysis showed DOP1-DES and DOP2-DES were composed of D-glucose and D-mannose with the ratio of 2.2:1 and 3.7:1, respectively. Structural features of DOP1-DES and DOP2-DES were investigated by a combination of FT-IR, methylation analysis and NMR, which indicated that both polysaccharides had a similarly backbone consisting of (1, 4)-linked β-D-Manp and (1, 4)-linked β-D-Glcp with different ratio. Simultaneously, the two fractions possessed considerable antioxidant activity. [ABSTRACT FROM AUTHOR]