International Journal of Biological Macromolecules最新文献

Structural modification/unfolding of starch molecules can be improved by radio frequency (RF) treatment. This necessitates a better understanding of its action mechanism through rapid heating and dipolar/ionic molecular vibration effects. Native maize starch (NS) was subjected to RF heating in a NaCl solution to five target temperatures, and its effect on structural modifications was evaluated. Results showed that the conductivity, particle size distribution and zeta potential of RF heated starch increased with increasing temperature. RF energy had a significant effect on the vibration intensity of other skeleton modes. No new chemical bonds/groups were formed in the starch even though there was the effect of sodium/chloride ions with the added vibration intensity of the ions and the dipolar rotation movements resulted in changes in the disordered and/or ordered structures. The RF treatment at 70 °C had the highest energy (10.4 kJ) of inter-strand hydrogen bond, crystallinity (36.6 %) and trough viscosity (2480 cp), but had the lowest crystallite dimension (13.7 nm), full width at half maximum (14.4) of peak at 480 cm^-1, and breakdown (534 cp) and setback (784 cp) viscosities based on X-ray diffraction, Fourier transform infrared, and Raman and RVA observations.

Marine algae biomass utilization has attracted considerable attention, however, the preparation of monosaccharides from raw algae is still hindered by many technical barriers. In this study, three genes, aga1365, aga1364, and aga1360, encoding key enzymes constituting a complete agar decomposition pathway were expressed and characterized. Recombinant Aga1365, Aga1364, and Aga1360 exhibited high optimal reaction temperatures and excellent thermal stability. Moreover, enzyme cocktail was proved to have higher synergistic effect to prepare monosaccharide from raw seaweed. The enzyme cocktail of Aga1360 (GH117) with Aga1365 (GH16) and enzyme cocktail of Aga1360 with both Aga1365 and 1364 (GH50) were used to synergistically degrade homogenized Gelidium amansii, maximum monosaccharide production of 21.47 mg/g and 39.28 mg/g could be achieved, respectively. This study presents an environment-friendly, time saving and efficient way to prepare monosaccharides from raw seaweed, which also provide a potential strategy to effectively convert algae biomass for biofuel and biochemical production by utilizing the synergistic effects of enzyme cocktail.

Given the exponential growth of the recombinant human collagen market, it is paramount to devise a robust and straightforward design strategy aimed at preserving the remarkable biological activity of recombinant human collagen while endowing it with tailored mechanical properties and stable morphologies. This innovative approach stands to broaden its applicability in hard tissue repair endeavors. Our study employed a synergistic approach of alkali hydrolysis and Schiff's base chemistry to graft Type I recombinant human collagen (rhCol-I) onto poly (L-lactic acid) (PLLA) membranes, yielding PLLA-rhCol composites. In vitro evaluations substantiated that this reengineered material not only retained the biological efficacy of rhCol-I but also imparted mechanical robustness and processability ideal for bone implant applications. Notably, it exhibited superior tissue engineering attributes, fostering proliferation, adhesion, osteogenic differentiation, mineralization of bone marrow mesenchymal stem cells (BMSCs), and encouraging vascularization. In a rat model of critical-sized bone defects, PLLA-rhCol exhibited markedly enhanced bone repair efficiency over conventional PLLA bone implants, achieving a bone volume fraction (BV/TV) of up to 32.57 ± 3.77 %, while promoting angiogenesis and effectively mitigating inflammatory cell infiltration. This pioneering method of modifying recombinant human collagen onto the side chains of polymeric macromolecules portends broad applicability in enhancing various biocompatible, yet mechanically robust and processable polymers, thereby expanding the horizons of recombinant human collagen utilization in tissue engineering and catering to the ever-evolving market demands.

The treatment of water contaminated with oil or organic solvents has always been a thorny challenge, considering the complexity of water pollution, the susceptibility to secondary pollution and the consequent depletion of resources. Biomass is a versatile, green and self-circulating natural material that shows important potential in designing high-performance oil/water separation materials. This review highlights the recent research progress on biomass-based materials (BBMs) in the field of oil-water separation. Firstly, related properties for displaying definitions, sources and specificities on biomass materials are introduced, and the basic wetting theory of interfacial wettability is discussed. Secondly, representative nature-inspired designing strategies for oil-water separation materials are summarized. Finally, the current development prospects, future challenges and trends on BBM for oil-water separation are discussed as well. Hopefully, this review will provide some essential guidelines for the researchers to design novel oil/water separation materials with green, self-degradable, low-toxicity and readily available raw materials.

Collagenase and protease productions from Aspergillus heteromorphus URM0269 were optimized by submerged fermentation using soybean flour as substrate. Fermentations were performed according to composite design using the concentrations of substrate and yeast extract as the independent variables. The best condition was scaled up in a stirred tank bioreactor to assess the fermentation kinetics. The highest production of both enzymes occurred at concentrations of 2.0 % substrate and 0.1 % yeast extract. Contrariwise, after scale-up, collagenase activity increased from 33.5 to 148.5 U/mL, while the protease decreased from 16.3 to 11.7 U/mL. A. heteromorphus URM0269 showed a maximum growth rate of 0.09 h^-1 and yields of protease and collagenase on biomass, after 65 h of 2.70 and 34.22 U/mgx, respectively. Collagenase acted optimally at 40 °C and pH 6.0 on collagen as a substrate and displayed an allosteric trend, achieving a maximum reaction rate of 132.47 U/mL. Thermodynamic parameters of collagen degradation such as Gibbs free energy (74.16 kJ/mol), enthalpy (11.64 kJ/mol), entropy (-199.63 J/K.mol), and activation energy (14.25 kJ/mol) were determined for optimal temperature. These results demonstrated that soybean flour is a potential agroindustrial residue for collagenase production. Furthermore, the collagenase displayed promising biochemical and thermodynamic features for other biotechnological applications.

Colletotrichum gloeosporioides is a model plant pathogenic fungus, and the appressoria are the main infection structures integral to the pathogenic process. Septin proteins play fundamental roles in facilitating shape alteration and organizing the F-actin cytoskeleton, thereby aiding the invasive growth of various fungi. Herein, we examined the roles of four septin-coding genes (CgSEP3, CgSEP4, CgSEP5, and CgSEP6) in C. gloeosporioides. Our findings reveal the diverse functions of septins in C. gloeosporioides, which encompass the regulation of vegetative growth, conidiation, cell wall integrity, and stress responses. Critically, septins are involved in the formation, invasion, and expansion of infection structures and they directly influence virulence on unwounded hosts. Interestingly, the deletion of CgSEP4 resulted in the formation of hooked and bent germ tubes and caused a significant decrease in appressorium turgor pressure, which has not been reported in other fungi. Our findings demonstrated that CgSEP3 and CgSEP6 were regulated by ROS signal transduction during the formation of infection structure. Moreover, the knockout of the key component, CgSEP5, significantly decreased growth rate compared to the wild type, completely blocking the penetration of infection structures and subsequently abolishing virulence on poplar leaves. By subcellular localization of GFP fusions, it was proved that CgSEP5 may regulate the formation of appressorial pegs in C. gloeosporioides through forming a ring-like structure inside the appressorium. Collectively, our research underscores the pivotal role of septins in fungal pathogenicity, by orchestrating the formation and development of infection structures. We speculate that CgSEP5 function as a promising anti-fungal target, and believe these findings provide a substantial reference for future investigations into the mechanisms underpinning the invasion of fungi appressoria on woody plants.

In this study, we endeavored to catalyze the biosynthesis of D-phenyllactic (D-PLA) from L-Phenylalanine (L-Phe) through a one-pot method. However, the crucial enzymes for the biosynthesis of phenylpyruvate (PPA), amino acid oxidase (L-AAD), is a membrane-bound protein. Herein, we proposed a novel co-immobilization strategy of whole cells and enzymes, integrating them into ZIF-90 to achieve efficient biosynthesis of D-PLA. Consequently, we embarked on integrating both enzyme and E. coli into ZIF-90, ultimately obtaining the novel biocatalyst E. coli/LDH@ZIF-90. This achievement facilitated the cascade reaction between LDH and E. coli, enabling a streamlined one-pot bioconversion process. The morphology and structure of E. coli/LDH@ZIF-90 were thoroughly characterized using a range of methods, including XRD, SEM, FT-IR, CLSM, and XPS, which confirmed that the material had been successfully synthesized. Further activity experiments revealed that E. coli/LDH@ZIF-90 exhibited good stability even under harsh conditions. Additionally, the biocatalyst retained 76 % of its initial catalytic activity after completing six cycles. Moreover, when utilized for the biosynthesis of D-PLA, this system demonstrated an impressive conversion rate of 85.2 % after 12 h. The successful cascade catalysis from L-Phe to D-PLA underscored the potential of the enzyme-cell cascade catalytic system, offering valuable insights for its potential industrial applications.

Triple-negative breast cancer (TNBC) presents formidable challenges due to its aggressive nature and high recurrence rates, compounded by the involvement of epithelial-mesenchymal transition (EMT) in its progression and metastasis. Standard chemotherapy, which typically employs doxorubicin (DOX), remains a primary treatment approach. However, multidrug resistance (MDR) mechanisms, which include ATP-binding cassette transporters and EMT, contribute to treatment failures. Ultrasound has emerged as a promising modality among the various strategies explored to address MDR in TNBC. It serves as a diagnostic tool and holds therapeutic potential by inducing various biological effects depending on the exposure level. Targeted nanoparticles offer a means to enhance drug delivery efficiency. Our study aims to advance ultrasound technology combined with biocompatible nanoparticles using simplified preparation methods to improve treatment outcomes for drug-resistant TNBC. In particular, employing DOX-loaded fucoidan/arginine-gelatin nanoparticles facilitated the targeted delivery of chemotherapy drugs to tumors by effectively interacting with P-selectin, resulting in tumor growth inhibition. Furthermore, these nanoparticles mitigated MDR and EMT, particularly when combined with ultrasound treatment. This integrated approach of nanoparticle delivery with ultrasonography opens up a promising and innovative avenue for clinical cancer research.

Drug conjugation with enzymes is one of the innovative antibacterial nanocarriers used as a delivery system for cancer therapy. Zeolitic imidazolate framework-8 (ZIF-8) was synthesized, dual encapsulated with cellulase (CL) enzyme, and resveratrol (Resv) drug formed ZIF-8@CL&Resv. Cellulase and resveratrol hydrophobic nature have bound them together and imparted a negative charge on the ZIF-8, resulting in the decrease of zeta potential from 22.7 mV (ZIF-8) to 3.82 mV (ZIF-8@CL&Resv). The cellulase like a scaffold regulated the pH-responsive release of resveratrol enhancing its bioavailability. Molecular docking studies provided evidence of the major interaction between the biofilm-related proteins with cellulase and resveratrol. The encapsulated cellulase showed high enzymatic activity and possibly exhibited antibacterial effects by dissolving the biofilm and exposing bacteria to resveratrol action. Resveratrol released sustainably exhibited significant antioxidant and antibacterial activity against selected bacterial species. ZIF-8@CL&Resv exhibited high biocompatibility and had a potent cytotoxic effect against triple-negative breast cancer cells MDA MB 231 with an IC₅₀-value of 17.18 μg/mL compared to ZIF-8 control with 90.47 μg/mL. ZIF-8@CL&Resv treatment led to 61.81 % cell death, apoptosis induction, increased ROS generation, and decreased mitochondrial membrane potential. Overall, data demonstrated that ZIF-8@CL&Resv is a novel drug release system and a potential catalytic nanoparticle for antimicrobial and anticancer applications.

Composting, a sustainable practice, facilitates the biodegradation of organic waste, notably lignocellulosic biomass, into value-added humic substances. Despite its potential, the application of electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to characterize dissolved organic matter (DOM) for assessing the changes in maturity during cow manure-straw composting is underexplored. Furthermore, the link between these changes, microbial community succession, and the biochemical pathways of humus formation is seldom investigated. This study leveraged ESI FT-ICR MS and metagenomic analysis to elucidate the molecular changes in DOM, identified key microbes in humus formation, and traced the humus formation pathway during composting. The results highlighted the crucial role of microorganisms such as Thermobifida, Luteimonas, Ascomycota, and Chloroflexi in accelerating the breakdown and transformation of plant biopolymers. Large molecular nitrogen compounds from cow manure-straw were converted into unsaturated, aromatic oxygen compounds, which resemble humic substances in their chemical properties. The ESI FT-ICR MS data revealed that humus formation occurred through a series of reactions, including protein deamination, lignin delignification, and decarbonylation. This research offered new light on strategies to enhance the stabilization and humification of cow manure-straw composting, contributing to more effective composting processes.