Biobased furans, such as furfural, 5-hydroxymethylfurfural, and 2,5-furandicarboxylic acid, are recognized as the top-value platform chemicals in the valorization of biomass to chemicals, fuels, and ...materials. Biocatalysis has emerged as a promising technique in the chemical and pharmaceutical industries because of exquisite selectivity, mild reaction conditions, environmental friendliness, etc. In this comprehensive review, we summarize the recent advances in (chemo)biocatalytic conversion of biobased furans, based on the reaction types including oxidation, reduction, C–C and C–N bonds formation, esterification, and amidation. Particularly, the biocatalysts and their catalytic mechanisms/pathways are critically discussed to allow the rational design and construction of efficient enzymes/multienzyme systems/chemobiocatalytic systems. Besides, various biocatalyst engineering and reaction engineering strategies are highlighted to intensify the processes. Future research directions are proposed to expand the chemical space of furans as well as to improve the commercial acceptance of biocatalytic processes.
Bioactive compounds have gained increasing attention for their health benefits. However, the instability of bioactive compounds during food processing and storage, and low bioavailability or chemical ...instability when exposed to upper gastrointestinal tract conditions significantly compromised the envisioned benefits, thus limiting their applications. Electrospinning has been recognized as a promising method to encapsulate bioactive compounds since it does not involve any severe conditions of temperature, pressure, or harsh chemicals. Therefore, the nanofibers produced by electrospinning have attracted particular attention in food industry due to the potential as vehicle for the encapsulation and controlled delivery or release of bioactive compounds.
Electrospinning is a novel delivery approach for bioactive compounds, it opens a new horizon in food technology with the possibility of commercialization in the near future. This paper presents a brief summary of electrospinning, and its application in encapsulation different types of bioactive compounds by biopolymer matrixes are also highlighted. Further, the existing limitations and scope for future research are discussed.
Recently, considerable studies have been carried out in encapsulation of bioactive compounds using electrospinning. The obtained nanofilm could enhance stability, encapsulation efficiency and oral bioavailability of bioactive compounds, as well as achieve targeted delivery and controlled release, thus facilitating the development of functional foods.
•Overview of electrospinning techniqueand its advantages.•Applications of electrospun biopolymer fibers in encapsulation of small molecules.•Applications of electrospunbiopolymer fibers in encapsulation of macromolecules.
•Highly ordered porous MOFs have been emerged as promising candidates for efficient immobilization of enzyme.•An update and systematic review about MOFs for enzyme immobilization is ...presented.•General strategies for preparation of MOFs-enzyme composites and the key factors during synthetic procedures are summarized.•MOFs-enzyme composites with significantly improved catalytic performances have been extensively utilized in different fields.•Research hotspots, barriers and future perspectives of this developing area are described.
As a typical green methodology, enzymatic catalysis has been extensively employed in multitudinous chemical and biological transformation procedures. However, intrinsic fragile nature of enzymes makes them prone to denaturation or destabilization in harsh practical conditions, leading to unavoidably shortened lifespan and extremely high cost. It was proven that enzyme immobilization is an efficient strategy for enhancing their catalytic performance in continuous industrial practices. Metal-Organic Frameworks (MOFs) with extremely high specific surface area, abundant porosity, extraordinary multifunctionality, and relatively high stability, in recent years, have attracted remarkable research interests as novel supporting matrices for efficient enzyme immobilization and protection. Many reported MOFs-enzyme composites exhibit unprecedented catalytic performances than those of free enzymes, including improved enzyme efficiency, stability, selectivity, and recyclability, due to the protection of enzymes by highly ordered frameworks. To present a systematic overview of this emerging and developing field, herein, we summarize an update review about the most recent advances in MOFs immobilizing enzymes from the aspects of general synthetic approaches, critical impact factors, enhanced catalytic performances, and the practical applications. Subsequently, the emerging theories, methodologies and technologies in this thriving area are briefly introduced. Finally, barriers and future perspectives about MOFs for enzyme immobilization are also discussed.
Furancarboxylic acids are promising biobased building blocks in pharmaceutical and polymer industries. In this work, dual‐enzyme cascade systems composed of galactose oxidase (GOase) and alcohol ...dehydrogenases (ADHs) are constructed for controlled synthesis of 5‐formyl‐2‐furancarboxylic acid (FFCA) and 2,5‐furandicarboxylic acid (FDCA) from 5‐hydroxymethylfurfural (HMF), based on the catalytic promiscuity of ADHs. The byproduct H2O2, which is produced in GOase‐catalyzed oxidation of HMF to 2,5‐diformylfuran (DFF), is used for horseradish peroxidase (HRP)‐mediated regeneration of the oxidized nicotinamide cofactors for subsequent oxidation of DFF promoted by an ADH, thus implementing H2O2 internal recycling. The desired products FFCA and FDCA are obtained with yields of more than 95 %.
Internal affairs: A dual‐enzyme cascade system, composed of galactose oxidase and alcohol dehydrogenases (ADHs), is developed for controlled synthesis of furancarboxylic acids from 5‐hydroxymethylfurfural, based on the catalytic promiscuity of ADHs. The byproduct H2O2 is used for horseradish peroxidase‐mediated regeneration of the oxidized nicotinamide cofactors, thus implementing H2O2 internal recycling.
Zeolitic imidazolate frameworks (ZIFs) serving as platforms for bioactive guest encapsulation have attracted growing attention, yet the tailoring of its architectures and bioactivity remains a major ...challenge. Herein, a versatile competitive coordination strategy is proposed by using amorphous zinc nucleotide gel as template for step‐by‐step growth of ZIFs, which enables the tailoring of bioactive ZIF composites under facile conditions. Mechanism investigation reveals that introduced nucleotide determines the hierarchical pore structure and hydrophilicity, leading to customized activity retention and stability of the resultant bioactive ZIF composites. Furthermore, nucleoside monophosphate enhances the acidic tolerance of ZIFs. To the authors’ knowledge, this is the first example showing the dynamic evolution of amorphous gels to crystalline ZIFs for in situ encapsulation of enzymes with tailored catalytic performance. This study provides insights for rational design of ZIF‐based biocomposites and broadens the application of bioactive metal–organic frameworks.
A facile competitive coordination strategy enables step‐by‐step evolution of amorphous gel to crystalline MOFs, which serves as an ideal platform for enzyme encapsulation in aqueous solution. The gradient changing chemistry including hierarchical porous structure and hydrophilicity endows the resultant bioactive MOFs composites with tailored catalytic performance.
Spermiogenesis is a highly orchestrated developmental process during which chromatin condensation decouples transcription from translation. Spermiogenic mRNAs are transcribed earlier and stored in a ...translationally inert state until needed for translation; however, it remains largely unclear how such repressed mRNAs become activated during spermiogenesis. We previously reported that the MIWI/piRNA machinery is responsible for mRNA elimination during late spermiogenesis in preparation for spermatozoa production. Here we unexpectedly discover that the same machinery is also responsible for activating translation of a subset of spermiogenic mRNAs to coordinate with morphological transformation into spermatozoa. Such action requires specific base-pairing interactions of piRNAs with target mRNAs in their 3′ UTRs, which activates translation through coupling with cis-acting AU-rich elements to nucleate the formation of a MIWI/piRNA/eIF3f/HuR super-complex in a developmental stage-specific manner. These findings reveal a critical role of the piRNA system in translation activation, which we show is functionally required for spermatid development.
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•MIWI/piRNA activates mRNA translation via imperfect base-pairing interactions•HuR and eIF3f are required for MIWI/piRNA-mediated target mRNA activation•piRNA system controls the translation of a subset of mRNAs in mouse spermatids•piRNA system plays a central role in acrosome formation during spermiogenesis
The piRNA pathway, through functional interplay with HuR and eIF3f, plays an important role in translational activation of a specific set of mRNAs during mouse spermiogenesis.
Recently, catalytic valorization of biomass‐derived furans has received growing interest. 5‐Aminomethyl‐2‐furancarboxylic acid (AMFC), a furan amino acid, holds great promise in the aeras of polymer ...and pharmaceutical, but its synthesis remains limited. In this work, we report a chemobiocatalytic route toward AMFC by combining laccase‐TEMPO system and recombinant Escherichia coli (named E. coli_TAF) harboring ω‐transaminase (TA), L‐alanine dehydrogenase (L‐AlaDH) and formate dehydrogenase (FDH), starting from 5‐hydroxymethylfurfural (HMF). In the cascade, HMF is oxidized into 5‐formyl‐2‐furancarboxylic acid (FFCA) by laccase‐TEMPO system, and then the resulting intermediate is converted into AMFC by E. coli_TAF via transamination with cheap ammonium formate instead of costly organic amine donors, theoretically generating H2O and CO2 as by‐products. The tandem process was run in a one‐pot twostep manner, affording AMFC with approximately 81 % yield, together with 10 % 2,5‐furandicarboxylic acid (FDCA) as by‐product. In addition, the scale‐up production of AMFC was demonstrated, with 0.41 g/L h productivity and 8.6 g/L titer. This work may pave the way for green manufacturing of the furan‐containing amino acid.
A chemobiocatalytic tandem process toward 5‐aminomethyl‐2‐furancarboxylic acid (AMFC) was developed by combining laccase‐TEMPO system and a whole‐cell catalyst in a single reaction vessel, starting from 5‐hydroxymethylfurfural (HMF) and inexpensive ammonium formate. The desired product was obtained with 81 % yield. More importantly, the scale‐up production of AMFC was demonstrated, with 0.41 g/L h productivity.
Electrospinning is a simple and versatile encapsulation technology. Since electrospinning does not involve severe conditions of temperature or pressure or the use of harsh chemicals, it has great ...potential for effectively entrapping and delivering bioactive compounds. Recently, electrospinning has been used in the food industry to encapsulate bioactive compounds into different biopolymers (carbohydrates and proteins), protecting them from adverse environmental conditions, maintaining the health-promoting properties, and achieving their controlled release. Electrospinning opens a new horizon in food technology with possible commercialization in the near future. This review summarizes the principles and the types of electrospinning processes. The electrospinning of biopolymers and their application in encapsulating of bioactive compounds are highlighted. The existing scope, limitations, and future prospects of electrospinning bioactive compounds are also presented.
Members of Bifidobacterium are among the first microbes to colonize the human intestine naturally, their abundance and diversity in the colon are closely related to host health. Recently, the gut ...microbiota has been gradually proven to be crucial mediators of various metabolic processes between the external environment and the host. Therefore, the health-promoting benefits of Bifidobacterium spp. and their applications in food have gradually been widely concerned. The main purpose of this review is to comprehensively introduce general features, colonization methods, and safety of Bifidobacterium spp. in the human gut, highlighting its health benefits and industrial applications. On this basis, the existing limitations and scope for future research are also discussed. Bifidobacteria have beneficial effects on the host's digestive system, immune system, and nervous system. However, the first prerequisite for functioning is to have enough live bacteria before consumption and successfully colonize the colon after ingestion. At present, strain breeding, optimization (e.g., selecting acid and bile resistant strains, adaptive evolution, high cell density culture), and external protection technology (e.g., microencapsulation and protectants) are the main strategies to address these challenges in food application.
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