Introduction:C1 gas bioconversion for single-cell protein (SCP) production offers dual environmental benefits by mitigating greenhouse gases and generating protein resources. This study systematically determined optimal methane-to-air ratios (CH4:air, v/v) for enhancing methane-oxidizing bacteria (MOB) growth and SCP yield under three distinct nitrogen assimilation modes: nitrate-driven pMMO expression, ammonium-driven sMMO expression, and nitrogen-fixing sMMO expression. Methods:Experiments were conducted under three nitrogen assimilation regimes: nitrate-fed pMMO expression, ammonium-fed sMMO expression, and nitrogen-fixing sMMO expression systems. By adjusting the volumetric ratio of methane to air, the effects on bacterial growth, biomass accumulation, specific growth rate, and key enzymatic activities were evaluated. Measured parameters included OD600, cell dry weight, specific growth rate (μmax), and nitrogenase activity in the nitrogen-fixing system. Data from repeated measurements were subjected to statistical analysis to clarify the regulatory role of gas ratios on metabolic pathways. Results:In the nitrate-fed pMMO expression system, a CH4:air ratio of 1:3 yielded optimal growth, with an OD600 of 1.11, cell dry weight of 0.44 ± 0.023 g/L, and μmax of 0.022 h-1. Similarly, the ammonium-fed sMMO expression system achieved best performance at the same ratio (OD600 1.19, biomass 0.56 ± 0.014 g/L, μmax 0.025 h-1). In contrast, the nitrogen-fixing sMMO expression system performed better at a lower oxygen ratio (CH4:air = 1:2), reaching an OD600 of 0.62, biomass of 0.28 ±0.008 g/L, nitrogenase activity of 1.09 nmol/(min mg protein), and μmax of 0.016 h-1). Discussion:The results reveal oxygen's critical dual role: higher O2 levels enhance methane oxidation by activating the copper-dependent catalytic site of pMMO but simultaneously and irreversibly damage the oxygen-sensitive nitrogenase ssential for N2 fixation, suppressing its activity. Conversely, lower O2 protects nitrogenase but limits pMMO efficiency. This creates a fundamental metabolic trade-off where the optimal CH4/O2 ratio balances these opposing effects, strategically partitioning cellular energy either toward efficient methane assimilation (favored by higher O2) or toward the ATP-intensive process of nitrogen fixation (requiring lower O2). These identified gas-ratio thresholds provide actionable parameters for designing scaled SCP bioproduction systems, enabling effective coupling of industrial methane mitigation with sustainable protein synthesis through gas-phase engineering.

Olefin hydroformylation is an important C1 chemical transformation that has been widely applied in the production of fine chemicals and chemical feedstocks.Although traditional homogeneous catalytic systems exhibit excellent catalytic activity and selectivity,they still suffer from severe problems such as difficult catalyst separation and metal loss.Therefore,the development of efficient and stable heterogeneous catalytic systems has become an important research direction in this field.Metal-organic frameworks(MOFs),owing to their high surface area,regular porous structures,and tunable framework compositions,have demonstrated unique advantages in heterogeneous catalysis.In recent years,MOFs and their derived catalytic materials have attracted much attention in hydroformylation reactions,especially the introduction of phosphine ligands into MOFs based on their framework characteristics to construct stable metal-phosphine active centers,providing a new approach to the heterogenization of homogeneous catalytic systems.This article reviews the series of research progress of MOFs catalysts in hydroformylation reactions,focusing on the preparation strategies,structural features,and reaction performance of phosphine-functionalized MOFs catalytic materials,and summarizes the main factors affecting activity and selectivity.On this basis,the challenges and future development directions of MOFs-based hydroformylation catalytic systems are prospected.

The effects of peroxidase and its mimic methanobactin-Cu on the structure of fermented-bran-supplemented wheat flour, as well as on dough processing, bread quality and functional properties were investigated to improve the quality of wheat bran flour. A catalytic system was established under the conditions of 4.5 × 10-5 mol/L methanobactin-Cu, 35 °C, 4 min and pH 6.5, achieving a ferulic acid binding rate 41.6%. Electrophoretic analysis confirmed the formation of high-molecular-weight gluten proteins (75-100 kDa). Spectroscopic characterization revealed that methanobactin-Cu-catalyzed di-polymerization of ferulic acid reinforced the gluten network structure. Dough hardness and water absorption decreased by 4.1% and 5.3%, respectively, exhibiting weak gel rheological properties. Additionally, the dough exhibited maximum elasticity (0.97), chewiness (160 N), extensibility (28.31), gas-holding height (111.4 mm), and bread sensory score (80 points), along with enhanced anti-digestion and antioxidant properties. These findings provide useful insights for the utilization of wheat bran.

Polyhydroxybutyrate (PHB) is a biodegradable polyester produced by microorganisms. Precise regulation of its molecular weight (Mw) and molecular weight distribution (MWD) is the core breakthrough for achieving high-value and scenario-based applications of PHB in the food industry. Based on critical analysis, this paper systematically discusses the advantages, disadvantages, and industrial adaptability of three core technologies for precise PHB Mw regulation: biosynthesis regulation, chemical/enzymatic modification regulation, and AI-assisted synthetic biology modification. This study investigates the comparative mechanical properties, degradability, food safety and cost-effectiveness of PHB and other mainstream biodegradable materials, including polylactic acid (PLA) and polybutylene succinate (PBS). The study identifies the distinct competitive advantages of PHB in applications such as high-barrier packaging, edible films and gut-targeted functional carriers. The paper focuses on the advantages, existing bottlenecks and proposed solutions for PHB with different Mw gradients in food packaging, eco-friendly processing aids, food preservation, functional carriers and ketogenic functional foods, highlighting their application advantages, existing bottlenecks and proposed solutions. It emphasised key elements for industrial implementation, including low-cost production processes, compatibility with food industry equipment, and food-grade safety standards and quality control systems. Finally, the paper examined emerging trends in the field, including AI-assisted precision regulation, smart food packaging and precision nutrition delivery systems. The present paper establishes a comprehensive logical framework comprising "technology comparison, application bottlenecks, solutions and future trends". This provides both theoretical guidance and technical support for the standardised and large-scale application of PHB in the food industry, thereby driving the sector's transition towards green and sustainable practices.

The efficient conversion of carbon dioxide (CO2) into value-added chemicals is crucial for sustainable development. Herein, we designed and synthesized a series of NiCo/NiCo-OH@NC-T catalysts via a hydrothermal-pyrolysis method for the N-formylation of amines with CO2 and H2. The relationship between their structure, activity, and the reaction mechanism was systematically investigated. Comprehensive characterization revealed that the pyrolysis temperature critically modulates the surface composition, finely tuning the ratio between metallic (Ni/Co) and hydroxide NiCo-OH species. The optimal NiCo/NiCo-OH@NC-450 catalyst, which features a balanced metal-hydroxide species and strong bimetallic synergy, demonstrated exceptional performance in the model reaction with morpholine, achieving complete conversion and 96% selectivity. A distinct volcano-shaped correlation was observed between catalytic activity and pyrolysis temperature, which is directly linked to the catalyst's hydrogen activation capacity and CO2 adsorption strength. Mechanistic studies, including in situ DRIFTS, identified a surface-adsorbed formate (HCOO*) as the pivotal C1 intermediate, providing direct evidence for the reaction pathway. This work underscores the significance of engineering multifunctional interfaces in bifunctional catalysts for efficient CO2 hydrogenation and provides fundamental insights into the underlying structure-activity relationship.

Ball milling enhanced enzyme catalysis is a novel biocatalytic and conversion technology that offers significant potential for development in the food manufacturing industry due to its high efficiency and environmental friendliness. This study aims to investigate the effects of ball milling on lipase-catalyzed synthesis of starch ferulate (SF), focusing on multi-scale structure, physicochemical properties, and digestive characteristics. The results indicate that ball milling enhanced lipase-catalyzed treatment effectively disrupts the dense granular structure of starch, reducing its particle size distribution (425.4 f 5.50 nm to 226.8 f 10.18 nm), relative crystallinity (42.21 f 1.24 to 13.27 f 1.53), short-range ordered structure (1.69 f 0.017 to 0.38 f 0.17), and double helix structure (1.25 f 0.035 to 0.84 f 0.010). As well, the gelatinization temperature and viscosity of SF prepared by ball milling enhanced lipase-catalyzed treatment were significantly decreased, and the anti-aging property and the content of resistant starch (8.48 f 0.52 to 24.83 f 0.91) were significantly increased. These results provide both a new insight into the preparation methods for phenolic acid-modified starch and facilitate the development of low-viscosity, processing-stable, functional starch products and starch gels.

The structure of heterogeneous catalysts should be understood at the atomic level because the metal centers supported on different defects on support surfaces have completely different microenvironments and reactive behaviors. However, due to the lack of a fundamental understanding of the surface properties of supports, like carbon materials, distinguishing properties of different metal sites on the supports has always been a challenge. In this study, we employed vanadium and platinum catalysts supported on functionalized carbon nanotubes to demonstrate that metal catalysts supported on carbon materials exhibit different properties depending on the type of surface functional groups. The oxygen functional groups on carbon form covalent bonds with the vanadium (or platinum) precursor, leading to atomically dispersed metal oxide (or metal) deposition. Comprehensive investigations were performed to demonstrate the differences in the interactions between the metal species and each type of functional group. The results revealed that vanadium species to carboxylic and anhydride groups agglomerated at lower temperatures than the species bonded to phenol groups. Moreover, the platinum species on different oxygen functional groups on the carbon nanotubes exhibited distinct catalytic activities in the reverse water-gas shift reaction. These results suggest that determining the surface chemistry of carbon materials used as supports is highly significant for developing carbon-based heterogeneous catalysts and understanding the related catalytic processes.

Oxidoreductases are basic enzymes that catalyze redox reactions within cells. Naturally occurring oxidoreductases have high catalytic activity and substrate specificity, playing critical roles in bioenergy metabolism, the food industry, and biotechnology. However, limitations, such as high cost, low stability, and poor tolerance to reaction conditions, restrict their practical applications. Developing enzyme mimics with natural oxidoreductase-like activity represents a promising alternative. This review summarizes the activity origins and activity sites of peptide-based oxidoreductase mimics, such as peroxidases, and elaborates on their design principles, construction strategies, distinctive advantages, current challenges, and development trends from the dual perspectives of functional and structural simulation. Future advances in understanding active sites, substrate binding mechanisms, diverse peptide sequences, and characterization techniques will be expected to make them strong competitors to natural enzymes, enabling broad applications in fields such as the food industry (protein modification, rapid testing), biocatalysis, and agricultural sustainability.

Hydroformylation of olefins is one of the highest-volume industrial reactions to meet the vast de-mands for aldehydes as well as their derivatives.Homogeneous Co complexes were the original catalysts industrialized since 1960s.Heterogeneous catalysis is considered superior owing to the facile separation of catalysts from products,shorter technical process,and reduced manufacturing costs.Unexpectedly,there has not been a single case of plant using heterogenized Co-based catalyst successfully.To address the separation issue and understand the catalytic mechanism of the reac-tions,this review summarizes the progress in heterogeneous systems and provides a detailed dis-cussion of their catalytic performance.Strategies for stabilizing Co species through support modifi-cation and additive incorporation are carefully considered to elucidate why heterogeneous systems have not yet succeeded on an industrial scale.Furthermore,we provide our insights for the devel-opment of heterogeneous catalytic hydroformylation,including the challenges,opportunities,and outlooks.The aim is to deepen the fundamental understanding of heterogeneous alkene hydro-formylation,guiding the community's research efforts towards realizing its successful application in the future.

The hydroformylation of olefins is a cornerstone of homogeneous catalysis and industrial chemistry, yet achieving precise regioselectivity, particularly for 1,3-butadiene, remains a formidable challenge. Here we introduce a transformative rhodium-based catalytic system that achieves unprecedented efficiency in the hydroformylation of 1,3-butadiene, yielding dialdehydes with exceptional efficiency (up to 88 %). Our strategy employs a mixed dual-ligand system combining a tetradentate phosphine ligand and a diphenylphosphane, which synergistically facilitate the two-stage hydroformylation process during the catalytic cycle of CO insertion. This cooperative function of mixed ligands enables the selective production of 2-ethylbutanedial with a recordbreaking iso-selectivity of up to 67.8 %. Mechanistic investigations, supported by computational and experimental studies, reveal the critical and competitive role of binary mixed-ligand catalysis (BMLC) and ligand-relay catalysis (LRC) in this reaction. Specifically, three coordination modes derived from multidentate phosphine and monodentate diphenylphosphane ligands alternately govern key steps of the catalytic cycle, including olefin activation and regioselective insertion.

A highly dispersed Rh catalyst supported on nitrogen-doped carbon nanotubes (CNTs) was prepared using a one-pot method and exhibited highly catalytic performance in the hydroformylation of olefin.

This study investigated the effect of ball milling on the degree of substitution, structure, and physicochemical properties of starch ferulate synthesized by lipase-catalyzed. Under the conditions of a ball milling time of 48 min, a ball milling speed of 6.25 m/s, and a mass ratio of ferulic acid to corn starch of 8.2 %, the complex index of the ferulic acid-starch complex and the degree of substitution of starch ferulate reached the maximum, which were 66.83 +/- 0.75 % and 0.00624 +/- 0.00032, respectively. Compared with the starch ferulate synthesized by lipase-catalyzed without ball milling, the degree of substitution was increased by 6.5 times. Ball milling promotes the formation of the ferulic acid-starch complex, which is beneficial to improve the degree of substitution of lipase-catalyzed synthesis of starch ferulate. Besides, the solubility, swelling, freeze-thaw stability, and anti-aging properties of starch were increased. The obtained results provided a theoretical foundation for broadening the application range of bio-modified starch.

Single cell protein (SCP) is widely used in food and feed due to its high protein content, rich essential amino acids, low fat content, and presence of various trace elements. It can serve as a dietary supplement in animal diets or as a substitute for certain proteins. Methane-oxidizing bacteria (MOB), which utilize methane as their sole carbon and energy source and are not limited by factors such as land or light, are a significant asset for SCP production. Their co-culture system with photosynthetic bacteria (PSB) can further enhance SCP production efficiency. By comparing monoculture and co-culture data, it was confirmed that a synergistic interaction based on intracellular substance exchange exists between two mixed microorganisms: adding intracellular substances from MOB increased the maximum OD600 of PSB by 19% and cell dry weight by 10%, while adding intracellular substances from PSB increased the OD600 of MOB by 32% and cell dry weight by 2.06 times. Under nitrogen-limited conditions, the co-culture system achieved 2.26 times higher OD600 and 2.6 times greater cell dry weight compared to monoculture, demonstrating that the nitrogen-fixing activity of PSB effectively supplemented nitrogen sources. In normal nitrogen-supplied medium, the co-culture increased methane consumption by 13% (0.1252 g vs. 0.1108 g), SCP yield by 8% (0.349 vs. 0.323 g DCW/g CH4), and cell dry weight by 21%. 16S rRNA analysis revealed that MOB dominated the co-culture system (46.25%), with photosynthetic cyanobacteria as a secondary component (10.9%), validating the ecological structure of this synergistic system. The research outcomes provide a novel and efficient co-culture model for optimizing industrial SCP production.

Trans-2-butene is regularly burned as a liquefied petroleum gas (LPG) component in several developing countries due to its inertness and inseparability in comparison to other butene isomers (1-butene and isobutene), resulting in low-value utilization of resource and environmental degradation. The generation of high-carbon olefins via trans-2-butene oligomerization has become one of the most effective ways for its high-value valorization. Octene is currently undersupplied via ethylene oligomerization, and its traditional crafts are costly due to separation from full-fraction alpha-olefins (C4-C30). In the present work, we synthesized a series of novel 2-phenyl-ketimine1,10-phenanthroline iron complexes (Fe0-Fe9). Fe2 catalyst realizes the dimerization of trans-2-butene through homogeneous catalysis at moderate conditions (0.2 MPa, 30 degrees C), obtaining 3,4-dimethyl-1-hexene with 99.9 % selectivity. In contrast to the reported heterogeneous catalysts, our catalytic system exhibits a considerable improvement in activity and selectivity.

In the context of the escalating shortage of global resources, mechanoenzymology has emerged as a transformative platform for the production of economically viable, high-value products. This innovative method employs mechanical force to drive enzyme-catalyzed reactions, demonstrating significant advantages in terms of green chemistry indicators, catalytic efficiency, and process sustainability. It has proven successful in various fields, including food processing, biopharmaceutical, and biomass resources development. The reaction system with solvent minimization has achieved an unprecedented increase in substrate concentration and effectively alleviated the technical bottleneck of the "solid effect" of the reaction substrate. This review focuses on the mechanisms of mechanoenzymatic reactions and introduces methods, such as ball milling, enzyme reactive extrusion, and sonocatalysis. By classification of the types of mechanoenzymatic reactions, it highlights their emerging potential in the fields of food, pharmaceuticals, and the development of agricultural and marine resources. Finally, the current challenges and future development trends of mechanoenzymatic technology are described in detail. This multidisciplinary framework paves the way for significant advances in green and sustainable chemistry, providing innovative solutions to global challenges in food safety and agricultural sustainability.

Alkynes have played pivotal roles in numerous synthetic transformations and materials science. Here, by developing nitrogen-deletion coupling, we describe a modular synthesis of alkynes from widely accessible nitriles by swapping the N atom to a C atom in cyano groups, where lithiated gem-diborylalkanes and tert-butyl nitrite are applied sequentially. NMR analysis and crystal structure show the nature of an intermediary a- boryl lithium enamine. A diverse range of nitriles are converted into various internal and terminal alkynes within a short reaction time, including alkynes bearing bulky secondary and tertiary alkyl substituents on both sides.

The development of phosphine ligands continues to be essential for palladium-catalyzed homogeneous carbonylation reactions, particularly in achieving high regioselectivity. In this study, a cyclosiloxane-based multi-dentate phosphine ligand, L1 (V4-4Ph2P), characterized by its high thermal stability and oxidation resistance, was synthesized through the radical addition of secondary phosphines to the double bonds of tetravinyltetramethylcyclotetrasiloxane. L1 was then used in the Pd-catalyzed alkoxycarbonylation of a variety of olefins, including terminal and internal alkenes, cyclic alkenes, aromatic terminal alkenes as well as tetra-, tri- and 1,1-disubstituted alkenes to afford the desired esters with moderate to good yields. As elucidated via DFT calculations and in situ IR spectroscopy, the optimum spatial chelation modes and high stability of Pd-H active species were responsible for the enhancement of catalytic efficiency.

Skeletal editing of the core structure of heterocycles offers new opportunities for chemical construction and is a promising yet challenging research topic that has recently gained increasing interest. However, several limitations of the reported systems remain to be addressed. For example, the reagents employed are generally in high-energy, such as chlorocarbene precursors, nitrene species, and metal carbenes, which are also associated with low atomic efficiencies. Thus, the development of simple systems for the skeletal editing of heterocycles is still desired. Herein, a straightforward and facile BH3-mediated skeletal editing of readily available indoles, benzimidazoles, and several other aromatic heterocycles is reported. Structurally diverse products were readily obtained, including tetrahydrobenzo azaborinines, diazaboroles, O-anilinophenylethyl alcohols, benzene-1,2-diamines, and more. Density functional theory (DFT) calculations and natural bond orbital (NBO) analysis revealed a BH3-induced C-N bond cleavage reaction pathway. An exciting and counterintuitive indole hydroboration phenomenon of -BH2 shift from C3-position to C2-position was disclosed. Moreover, the photophysical properties of the synthesized diazaboroles were studied, and an interestingly and pronounced aggregation-induced emission (AIE) behavior was disclosed.