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1.
J Agric Food Chem ; 72(38): 21208-21220, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39285773

RESUMO

Lignosulfonate (LS), kraft lignin (KL), and organosolv lignin (OL) were evaluated as potential modulating agents of the physicochemical properties of Port wine at two different concentrations for 7 and 30 days. KL and LS demonstrated the ability to remove proteins and potentiate the anthocyanin concentration. LS reduced the tannin content and the interaction of salivary acidic proline-rich proteins with wine phenolic compounds. None of the lignin promoted a perceptible color change; however, the yellowish color of KL and OL at 100 g/hL contributed to an increase in the yellow tones of wines. Lignin improved wine aroma by reducing the amount of unwanted volatiles by 30% and increasing the content of ethyl esters associated with fruity aromas by up to 60%. The results suggest that lignin, especially LS, can be employed as a modulating agent, positively impacting wine's physicochemical properties. This valorization of a byproduct opens up new opportunities for the wine industry.


Assuntos
Lignina , Odorantes , Vinho , Vinho/análise , Lignina/química , Biopolímeros/química , Odorantes/análise , Cor , Taninos/química , Vitis/química , Fenóis/química , Antocianinas/química
2.
ACS Appl Mater Interfaces ; 16(39): 52878-52893, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39301782

RESUMO

To realize the health benefits of probiotic bacteria, they must withstand processing and storage conditions and remain viable after use. The encapsulation of these probiotics in the form of microspheres containing tapioca flour as a prebiotic and vehicle component in their structure or shell affords symbiotic effects that improve the survival of probiotics under unfavorable conditions. Microencapsulation is one such method that has proven to be effective in protecting probiotics from adverse conditions while maintaining their viability and functionality. The aim of the work was to obtain high-quality microspheres that can act as carriers of Lactobacillus casei bacteria and to assess the impact of encapsulation on the viability of probiotic microorganisms in alginate microspheres enriched with a prebiotic (tapioca flour) and additionally coated with hyaluronic acid, chitosan, or gelatin. The influence of the composition of microparticles on the physicochemical properties and the viability of probiotic bacteria during storage was examined. The optimal composition of microspheres was selected using the design of experiments using statistical methods. Subsequently, the size, morphology, and cross-section of the obtained microspheres, as well as the effectiveness of the microsphere coating with biopolymers, were analyzed. The chemical structure of the microspheres was identified by using Fourier-transform infrared spectrophotometry. Raman spectroscopy was used to confirm the success of coating the microspheres with the selected biopolymers. The obtained results showed that the addition of tapioca flour had a positive effect on the surface modification of the microspheres, causing the porous structure of the alginate microparticles to become smaller and more sealed. Moreover, the addition of prebiotic and biopolymer coatings of the microspheres, particularly using hyaluronic acid and chitosan, significantly improved the survival and viability of the probiotic strain during long-term storage. The highest survival rate of the probiotic strain was recorded for alginate-tapioca flour microspheres coated with hyaluronic acid, at 5.48 log CFU g-1. The survival rate of L. casei in that vehicle system was 89% after storage for 30 days of storage.


Assuntos
Alginatos , Lacticaseibacillus casei , Manihot , Microesferas , Probióticos , Lacticaseibacillus casei/química , Alginatos/química , Alginatos/farmacologia , Probióticos/química , Manihot/química , Farinha , Biopolímeros/química , Biopolímeros/farmacologia , Quitosana/química , Quitosana/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia
3.
Molecules ; 29(18)2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39339400

RESUMO

In the recent era, bio-nanocomposites represent an emerging group of nanostructured hybrid materials and have been included in a new field at the frontier of materials science, life sciences, and nanotechnology. These biohybrid materials reveal developed structural and functional features of great attention for diverse uses. These materials take advantage of the synergistic assembling of biopolymers with nanometer-sized reinforcements. Conversely, polysaccharides have received great attention due to their several biological properties like antimicrobial and antioxidant performance. They mainly originated in different parts of plants, animals, seaweed, and microorganisms (bacteria, fungi, and yeasts). Polysaccharide-based nanocomposites have great features, like developed physical, structural, and functional features; affordability; biodegradability; and biocompatibility. These bio-based nanocomposites have been applied in biomedical, water treatment, food industries, etc. This paper will focus on the very recent trends in bio-nanocomposite based on polysaccharides for diverse applications. Sources and extraction methods of polysaccharides and preparation methods of their nanocomposites will be discussed.


Assuntos
Nanocompostos , Polissacarídeos , Nanocompostos/química , Biopolímeros/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Animais , Materiais Biocompatíveis/química , Nanotecnologia/métodos
4.
Biomater Adv ; 165: 214009, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39216319

RESUMO

Ureteral stents are indwelling medical devices that are most commonly used in treating different urinary tract complications like ureteral obstruction, kidney stones, and strictures, and allow normal urine flow from the kidney to the bladder. Tremendous work has been done in ureteral stent technology to meet the clinical demands, however, till-date a gold standard material for ureteral stents has not yet been developed. Many materials such as metal, and synthetic polymers have been published, however, the role of natural biopolymers has not yet been summarized and discussed. There is no detailed review published to explain the role of natural biopolymers in ureteral stent technology. This is the first review that explains and summarizes the role of natural polymer in ureter stent technology. In this review alginate and chitosan polymers are discussed in detail in the fabrications and coating of ureteral stents. It was summarized that alginate polymer alone or in combination with other polymers have been successfully used by many researchers for the manufacturing of ureteral stents with satisfactory results in vitro, in vivo, and clinical trials. However, alginate is rarely used to coat the surface of ureteral stent. On the other hand, only two reports are available on chitosan polymers for the manufacturing of ureteral stents, however, chitosan is largely used to coat the existing ureteral stents owing to their good antibacterial characteristics. Coating procedures can inhibit encrustation and biofilm formation. Nevertheless, the lack of antibacterial efficiency and inadequate coating limit their applications, however, natural biopolymers like chitosan showed significant promises in coating. Overall, the renewable nature, abundant, biocompatible, and biodegradable potential of natural polymer can be established with significant aspects as the ideal ureteral stent. To fully utilize the potential of the natural biopolymers in the ureteral stent design or coatings, an in-depth study is required to understand and identify their performance both in vitro and in vivo in the urinary tract.


Assuntos
Quitosana , Materiais Revestidos Biocompatíveis , Stents , Ureter , Humanos , Stents/efeitos adversos , Biopolímeros/química , Ureter/cirurgia , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Alginatos/química , Animais
5.
Food Funct ; 15(17): 8848-8864, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39118584

RESUMO

Digestion of macro-nutrients (protein and starch) in pulses is a consequence of the interplay of both extrinsic (process-related) and intrinsic (matrix-dependent) factors which influence their level of encapsulation and physical state, and therefore, their accessibility by the digestive enzymes. The current work aimed at understanding the consequences of hydrothermally induced changes in the physical state of cell biopolymers (cell wall, protein, and starch) in modulating the digestion kinetics of starch and proteins in common beans. The hydrothermal treatments were designed such that targeted microstructural/biopolymer changes occurred. Therefore, bean samples were processed at temperatures between 60 and 95 °C for 90 minutes. It was demonstrated that these treatments allowed the modulation of starch gelatinization, protein denaturation and cell separation. The specific role of hydrothermally induced starch gelatinization and protein denaturation, alongside enhanced cell wall permeability on the digestion kinetics of common bean starch and proteins is illustrated. For instance, bean samples processed at T > 70 °C were marked by higher levels of starch digestibility (Cf values above 47%) compared to the partially (un-)gelatinized samples (processed at T ≤ 70 °C) (Cf values below 35%). Similarly, samples processed at T > 85 °C exhibited significantly higher levels of protein digestibility (Cf values above 47%) resulting from complete protein denaturation. Moreover, increased permeability of the cell wall to digestive enzymes in these samples (T > 85 °C) increased levels of digestibility of both gelatinized starch and denatured proteins. This study provides an understanding of the potential use of hydrothermal processing to obtain pulse-based ingredients with pre-determined microstructural and nutritional characteristics.


Assuntos
Cotilédone , Digestão , Phaseolus , Proteínas de Plantas , Amido , Amido/metabolismo , Amido/química , Phaseolus/química , Cotilédone/química , Cotilédone/metabolismo , Biopolímeros/química , Biopolímeros/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Temperatura Alta , Manipulação de Alimentos/métodos , Parede Celular/metabolismo , Parede Celular/química , Cinética
6.
Int J Biol Macromol ; 278(Pt 3): 134684, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39214830

RESUMO

A new formulation that gradually released encapsulated Thuja plicata essential oil (TPEO) as an active component from a biopolymer matrix within a given period was obtained. Antimicrobial activity was determined in in-vitro tests where pure TPEO successfully inhibited the development of different Phytophthora species. The TPEO essential oil was encapsulated into the biopolymer matrix and an oil-in-water emulsion was formed. FTIR spectra analysis confirmed the formation of electrostatic interaction between these polymers, and hydrogen interactions between active components of TPEO and polymer chains. The stability of the emulsions was confirmed by zeta potential measurements, with a value of about 30 mV, even after 14 days of aging. UV-Vis spectra analysis revealed that >60 % of TPEO remained in the emulsion after 14 days of exposure to ambient conditions, whereas pure TPEO evaporated faster, and around 20 % remained after 6 days. Encapsulated TPEO almost completely inhibited the growth of Phytophthora species during the ten-day day's exposition being statistically significantly improved compared to fungicide treatment. It was demonstrated that the emulsion exhibited a prolonged antimicrobial effect and successfully suppressed the growth of Phytophthora species, and can be considered as a means of protection in forests and crops.


Assuntos
Óleos Voláteis , Phytophthora , Phytophthora/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Biopolímeros/química , Biopolímeros/farmacologia , Praguicidas/química , Praguicidas/farmacologia , Raízes de Plantas/química , Emulsões/química , Testes de Sensibilidade Microbiana
7.
Int J Biol Macromol ; 278(Pt 1): 134658, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39128751

RESUMO

Protein and polysaccharides are the mostly used biopolymers for developing packaging film and their combination-based composite produced better quality film compared to their single counterpart. The combination of protein and polysaccharides are superior owing to the better physical properties like water resistance, mechanical and barrier properties of the film. The protein/polysaccharide-based composite film showed promising result in active and smart food packaging regime. This work discussed the recent advances on the different types of protein/polysaccharide combinations used for making bio-based sustainable packaging film formulation and further utilized in food packaging applications. The fabrication and properties of various protein/polysaccharide combination are comprehensively discussed. This review also presents the use of the multifunctional composite film in meat, fish, fruits, vegetables, milk products, and bakery products, etc. Developing composite is a promising approach to improve physical properties and practical applicability of packaging film. The low water resistance properties, mechanical performance, and barrier properties limit the real-time use of biopolymer-based packaging film. The combination of protein/polysaccharide can be one of the promising solutions to the biopolymer-based packaging and thus recently many works has been published which is suitable to preserve the shelf life of food as well trace the food spoilage during food storage.


Assuntos
Materiais Biocompatíveis , Embalagem de Alimentos , Polissacarídeos , Embalagem de Alimentos/métodos , Polissacarídeos/química , Materiais Biocompatíveis/química , Proteínas/química , Biopolímeros/química , Animais
8.
Int J Biol Macromol ; 278(Pt 2): 134708, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151867

RESUMO

Aluminum­lithium (AlLi) alloy polishing and grinding processes in wet dust collector systems could cause hydrogen fire and explosion. From the fundamental perspective of preventing hydrogen explosions, a safe, nontoxic, and sustainable modified green hydrogen inhibitor based on chitosan (CS) and sodium alginate (SA) was developed in this study and was used as a hydrogen evolution inhibitor for the processing of waste dust from AlLi alloys. The structure and elemental distribution of the synthesized material were characterized through characterization experiments. Hydrogen evolution experiments and a hydrolysis kinetic model were used to explore the inhibitory effect of modified CS/SA on AlLi alloy dust, and the results revealed that the inhibitory concentration of the hydrogen explosion lower limit was 0.40 wt%, with an inhibition efficiency of 91.93 %, indicating an 11.88-61.44 % improvement over that of CS and SA. As the inhibitor concentration increased and the temperature decreased, the hydrogen inhibition effect increased. Characterization experiments and density functional theory showed that CS/SA primarily formed a dense physical protective barrier on the dust surface through chemical adsorption and complexation reactions, interrupting the hydrogen evolution reaction between the metal and water. This study introduces a novel green modified hydrogen inhibitor that fundamentally addresses hydrogen generation and explosion.


Assuntos
Alginatos , Ligas , Quitosana , Hidrogênio , Quitosana/química , Hidrogênio/química , Alginatos/química , Ligas/química , Poeira/análise , Biopolímeros/química , Cinética , Química Verde
9.
Adv Colloid Interface Sci ; 332: 103278, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39153416

RESUMO

Biopolymer hydrogels have a broad range of applications as soft materials in a variety of commercial products, including foods, cosmetics, agrochemicals, personal care products, pharmaceuticals, and biomedical products. They consist of a network of entangled or crosslinked biopolymer molecules that traps relatively large quantities of water and provides semi-solid properties, like viscoelasticity or plasticity. Composite biopolymer hydrogels contain inclusions (fillers) to enhance their functional properties, including solid particles, liquid droplets, gas bubbles, nanofibers, or biological cells. These fillers vary in their composition, size, shape, rheology, and surface properties, which influences their impact on the rheological properties of the biopolymer hydrogels. In this article, the various types of biopolymers used to fabricate composite hydrogels are reviewed, with an emphasis on edible proteins and polysaccharides from sustainable sources, such as plants, algae, or microbial fermentation. The different kinds of gelling mechanism exhibited by these biopolymers are then discussed, including heat-, cold-, ion-, pH-, enzyme-, and pressure-set mechanisms. The different ways that biopolymer molecules can organize themselves in single and mixed biopolymer hydrogels are then highlighted, including polymeric, particulate, interpenetrating, phase-separated, and co-gelling systems. The impacts of incorporating fillers on the rheological properties of composite biopolymer hydrogels are then discussed, including mathematical models that have been developed to describe these effects. Finally, potential applications of composite biopolymer hydrogels are presented, including as delivery systems, packaging materials, artificial tissues, wound healing materials, meat analogs, filters, and adsorbents. The information provided in this article is intended to stimulate further research into the development and application of composite biopolymer hydrogels.


Assuntos
Hidrogéis , Hidrogéis/química , Biopolímeros/química , Reologia , Polissacarídeos/química
10.
Int J Biol Macromol ; 277(Pt 4): 134516, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39106930

RESUMO

Biomass-based adsorbent materials are characterized by their low cost, environmental friendliness, and ease of design and operation. In this study, biomass-based hydrogel microspheres erbium alginate (SA/Er) with high stability and adsorption properties were prepared by a one-step synthesis method. The prepared materials were characterized and analyzed by SEM-EDS, XRD, TGA, FT-IR, UV-Vis, BET-BJH and XPS, and the adsorption performance of SA/Er was investigated for high concentrations of azo dyes in water. The results showed that the adsorption performance of SA/Er on the azo dyes of direct violet N (DV 1) and direct dark green NB (DG 6) with concentrations of 850 mg/L and 1100 mg/L under the optimal conditions was very high, and the adsorption amount could be up to 692 mg/g and 864 mg/g, respectively. The adsorption process was in accordance with the quasi-secondary kinetic model, which was accomplished by physical and chemical adsorption; the Langmuir isothermal model was able to better respond to the adsorption equilibrium, and the adsorption was dominated by the adsorption of surface monolayers; after seven desorption cycles, the removal of both azo dyes by the adsorbent material could reach >79.7 %. Combined with the results of FT-IR, UV-vis and XPS analysis before and after the adsorption, it was revealed that the adsorption of SA/Er with the dye molecules mainly consisted of hydrogen bonding, electrostatic adsorption and surface complexation, which resulted in the significant adsorption effect on the two azo dyes, and the above results can provide a reference for the treatment of dye wastewater.


Assuntos
Alginatos , Corantes , Poluentes Químicos da Água , Alginatos/química , Adsorção , Cinética , Corantes/química , Corantes/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Biopolímeros/química , Compostos Azo/química , Compostos Azo/isolamento & purificação , Purificação da Água/métodos , Microesferas , Hidrogéis/química , Espectroscopia de Infravermelho com Transformada de Fourier
11.
Curr Opin Biotechnol ; 89: 103192, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39216163

RESUMO

Biofilms play important roles in water technologies such as membrane treatments and activated sludge. The extracellular polymeric substances (EPS) are key components of biofilms. However, the precise nature of these substances and how they influence biofilm formation and behavior remain critical knowledge gaps. EPS are produced by many different microorganisms and span multiple biopolymer classes, which each require distinct strategies for characterization. The biopolymers additionally associate with each other to form insoluble complexes. Here, we explore recent progress toward resolving the structures and functions of EPS, where a shift towards direct functional assessments and advanced characterization techniques is necessary. This will enable integration with better microbial community and omics analyses to understand EPS biosynthesis pathways and create further opportunities for EPS control and valorization.


Assuntos
Biofilmes , Matriz Extracelular de Substâncias Poliméricas , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Purificação da Água/métodos , Biopolímeros/química , Biopolímeros/metabolismo
12.
Molecules ; 29(16)2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39202917

RESUMO

Lignocellulose is a major biopolymer in plant biomass with a complex structure and composition. It consists of a significant amount of high molecular aromatic compounds, particularly vanillin, syringeal, ferulic acid, and muconic acid, that could be converted into intracellular metabolites such as polyhydroxyalkanoates (PHA) and hydroxybutyrate (PHB), a key component of bioplastic production. Several pre-treatment methods were utilized to release monosaccharides, which are the precursors of the relevant pathway. The consolidated bioprocessing of lignocellulose-capable microbes for biomass depolymerization was discussed in this study. Carbon can be stored in a variety of forms, including PHAs, PHBs, wax esters, and triacylglycerides. From a biotechnology standpoint, these compounds are quite adaptable due to their precursors' utilization of hydrogen energy. This study lays the groundwork for the idea of lignocellulose valorization into value-added products through several significant dominant pathways.


Assuntos
Lignina , Lignina/química , Lignina/metabolismo , Biomassa , Alimentos , Poli-Hidroxialcanoatos/química , Poli-Hidroxialcanoatos/biossíntese , Poli-Hidroxialcanoatos/metabolismo , Resíduos , Biopolímeros/química , Biopolímeros/metabolismo , Perda e Desperdício de Alimentos
13.
Food Chem ; 460(Pt 3): 140699, 2024 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-39116772

RESUMO

This study aimed to prepare Glucono-δ-lactone (GDL)-induced Chlorella pyrenoidosa protein (CPP) hydrogel and further investigate the effect of polysaccharides on the mechanical properties and stability enhancement of the composite hydrogels. Polysaccharides composed of different ratios of low acyl gellan gum (GE) and guar gum (GU) imparted dense honeycomb-like networks and adjustable textural properties to the composite hydrogels induced by CaCl2. In particular, the hardness of hydrogels increased significantly from 14 to 833 g. Scanning electron microscopy results revealed that CPP-GE/GU composite hydrogels had better stable spatial porous structures. Moreover, fourier transform infrared spectroscopy (FTIR) indicated hydrogen bonding interaction between CPP and GE/GU. The composite network showed improved viscoelasticity, increased thermal stability, and self-healing ability of hydrogels. The composite hydrogels also showed high water holding (89-98%) and swelling (747-862%) properties compared to the pure CPP hydrogel. These findings further expand CPP hydrogel products and broaden application in plant protein-based food.


Assuntos
Chlorella , Hidrogéis , Hidrogéis/química , Chlorella/química , Biopolímeros/química , Proteínas de Plantas/química , Mananas/química , Mananas/farmacologia , Gomas Vegetais/química , Galactanos/química , Galactanos/farmacologia
14.
J Mech Behav Biomed Mater ; 159: 106694, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39191061

RESUMO

The demand for synthetic bone graft biomaterials has grown in recent years to alleviate the dependence on natural bone grafts and metal prostheses which are associated with significant practical and clinical issues. Biopolymer nanocomposites are a class of materials that display strong potential for these synthetic materials, especially when processed using additive manufacturing technologies. Novel nanocomposite biomaterials capable of masked stereolithography printing have been developed from functionalized plant-based monomers and hydroxyapatite (HA) with mechanical properties exceeding those of commercial bone cements. However, these biomaterials have not been evaluated under relevant physiological conditions. The effects of temperature (room temperature vs. 37 °C) and water absorption on the physical, surface, and mechanical properties of HA-containing biopolymer nanocomposites were investigated. Exposure to relevant conditions led to substantial impacts on material performance, such as significantly reduced mechanical strength and stiffness. For instance, a composite containing 10 vol% HA and functionalized monomers had 26 and 21% reductions in compressive yield strength and elastic modulus, respectively. After 14 days incubation in phosphate buffered saline, the same composition displayed a 62% decrease in compressive yield strength to 28 MPa. This manuscript demonstrates the relevance and importance of evaluating biomaterials under appropriate physiological conditions throughout their development and provides direction for future material development of HA-containing biopolymer nanocomposites.


Assuntos
Teste de Materiais , Fenômenos Mecânicos , Nanocompostos , Impressão Tridimensional , Nanocompostos/química , Biopolímeros/química , Temperatura , Materiais Biocompatíveis/química , Durapatita/química , Força Compressiva , Água/química , Meio Ambiente
15.
Plant Physiol Biochem ; 215: 109049, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39151366

RESUMO

Integrating agricultural, chemical, and technological knowledge is crucial for developing bio-nanotechnologies to improve agricultural production. This study explores the innovative use of biopolymeric coatings, based on sodium alginate and sodium alginate + Laponite® (nanoclay), containing biostimulants (tryptophol and thymol) or not, on garlic cloves. These coatings were analyzed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR-ATR), and scanning electron microscopy (SEM). Greenhouse bioassays showed improvements in garlic shoot plant biomass with both treatments: sodium alginate biopolymer and sodium alginate biopolymer plus Laponite®. In the field experiment, garlic plants treated with sodium alginate, in combination with conventional pesticide treatments, resulted in better quality garlic bulbs, where larger garlics were harvested in this treatment, reducing commercial losses. In tropical garlic crops, obtaining plants with greater initial vigor is essential. Our results highlight the potential of these bio-nanotechnological strategies to enhance garlic propagation, ensuring environmental protection and food security.


Assuntos
Alho , Alho/química , Biopolímeros/química , Alginatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X , Microscopia Eletrônica de Varredura , Nanotecnologia/métodos
16.
Int J Mol Sci ; 25(15)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39126018

RESUMO

Cassava starch solid biopolymer electrolyte (SBPE) films were prepared by a thermochemical method with different concentrations of lithium triflate (LiTFT) as a dopant salt. The process began with dispersing cassava starch in water, followed by heating to facilitate gelatinization; subsequently, plasticizers and LiTFT were added at differing concentrations. The infrared spectroscopy analysis (FTIR-ATR) showed variations in the wavenumber of some characteristic bands of starch, thus evidencing the interaction between the LiTFT salt and biopolymeric matrix. The short-range crystallinity index, determined by the ratio of COH to COC bands, exhibited the highest crystallinity in the salt-free SBPEs and the lowest in the SBPEs with a concentration ratio (Xm) of 0.17. The thermogravimetric analysis demonstrated that the salt addition increased the dehydration process temperature by 5 °C. Additionally, the thermal decomposition processes were shown at lower temperatures after the addition of the LiTFT salt into the SBPEs. The differential scanning calorimetry showed that the addition of the salt affected the endothermic process related to the degradation of the packing of the starch molecules, which occurred at 70 °C in the salt-free SBPEs and at lower temperatures (2 or 3 °C less) in the films that contained the LiTFT salt at different concentrations. The cyclic voltammetry analysis of the SBPE films identified the redox processes of the glucose units in all the samples, with observed differences in peak potentials (Ep) and peak currents (Ip) across various salt concentrations. Electrochemical impedance spectroscopy was used to establish the equivalent circuit model Rf-(Cdl/(Rct-(CPE/Rre))) and determine the electrochemical parameters, revealing a higher conduction value of 2.72 × 10-3 S cm-1 for the SBPEs with Xm = 17 and a lower conduction of 5.80 × 10-4 S cm-1 in the salt-free SBPEs. It was concluded that the concentration of LiTFT salt in the cassava starch SBPE films influences their morphology and slightly reduces their thermal stability. Furthermore, the electrochemical behavior is affected in terms of variations in the redox potentials of the glucose units of the biopolymer and in their ionic conductivity.


Assuntos
Condutividade Elétrica , Eletrólitos , Manihot , Amido , Amido/química , Manihot/química , Eletrólitos/química , Termogravimetria , Biopolímeros/química , Mesilatos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Varredura Diferencial de Calorimetria
17.
PLoS Comput Biol ; 20(8): e1012320, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39116194

RESUMO

Although depolymerization of complex carbohydrates is a growth-limiting bottleneck for microbial decomposers, we still lack understanding about how the production of different types of extracellular enzymes affect individual microbes and in turn the performance of whole decomposer communities. In this work we use a theoretical model to evaluate the potential trade-offs faced by microorganisms in biopolymer decomposition which arise due to the varied biochemistry of different depolymerizing enzyme classes. We specifically consider two broad classes of depolymerizing extracellular enzymes, which are widespread across microbial taxa: exo-enzymes that cleave small units from the ends of polymer chains and endo-enzymes that act at random positions generating degradation products of varied sizes. Our results demonstrate a fundamental trade-off in the production of these enzymes, which is independent of system's complexity and which appears solely from the intrinsically different temporal depolymerization dynamics. As a consequence, specialists that produce either exo- or only endo-enzymes limit their growth to high or low substrate conditions, respectively. Conversely, generalists that produce both enzymes in an optimal ratio expand their niche and benefit from the synergy between the two enzymes. Finally, our results show that, in spatially-explicit environments, consortia composed of endo- and exo-specialists can only exist under oligotrophic conditions. In summary, our analysis demonstrates that the (evolutionary or ecological) selection of a depolymerization pathway will affect microbial fitness under low or high substrate conditions, with impacts on the ecological dynamics of microbial communities. It provides a possible explanation why many polysaccharide degraders in nature show the genetic potential to produce both of these enzyme classes.


Assuntos
Bactérias , Biopolímeros/metabolismo , Biopolímeros/química , Bactérias/metabolismo , Bactérias/enzimologia , Modelos Biológicos , Biologia Computacional
18.
Environ Microbiol ; 26(8): e16687, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39168162

RESUMO

Heterotrophic bacteria in the ocean initiate biopolymer degradation using extracellular enzymes that yield low molecular weight hydrolysis products in the environment, or by using a selfish uptake mechanism that retains the hydrolysate for the enzyme-producing cell. The mechanism used affects the availability of hydrolysis products to other bacteria, and thus also potentially the composition and activity of the community. In marine systems, these two mechanisms of substrate processing have been studied in the water column, but to date, have not been investigated in sediments. In surface sediments from an Arctic fjord of Svalbard, we investigated mechanisms of biopolymer hydrolysis using four polysaccharides and mucin, a glycoprotein. Extracellular hydrolysis of all biopolymers was rapid. Moreover, rapid degradation of mucin suggests that it may be a key substrate for benthic microbes. Although selfish uptake is common in ocean waters, only a small fraction (0.5%-2%) of microbes adhering to sediments used this mechanism. Selfish uptake was carried out primarily by Planctomycetota and Verrucomicrobiota. The overall dominance of extracellular hydrolysis in sediments, however, suggests that the bulk of biopolymer processing is carried out by a benthic community relying on the sharing of enzymatic capabilities and scavenging of public goods.


Assuntos
Bactérias , Sedimentos Geológicos , Sedimentos Geológicos/microbiologia , Biopolímeros/metabolismo , Bactérias/metabolismo , Hidrólise , Água do Mar/microbiologia , Água do Mar/química , Polissacarídeos/metabolismo , Regiões Árticas , Svalbard , Mucinas/metabolismo
19.
Int J Biol Macromol ; 277(Pt 2): 134347, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094872

RESUMO

Chitosan is used in many applications due to its biodegradability, biocompatibility, nontoxicity, nonadhesiveness, and film-forming capabilities. Chitosan has antibacterial and antifungal activities, which are two of its other desirable attributes. However, chitosan can only dissolve in acidic liquids (1-3 % acetic acid), limiting its practical application. The hydroxyl and amino functional groups in the chitosan backbone are essential for chemical modification, which is a viable alternative for overcoming this obstacle. So, N- or O-, and N, O-substituted chitosan may yield derivatives with increased water solubility, biocompatibility, biodegradability, and bio-evaluation. In the same manner, the physicochemical properties of chitosan, including its mechanical and thermal properties, can be improved by cross-linking reactions. This review provides an overview of chitosan, including its origins and their solubility. Also, the review extend and discuss in details most of all chemical reactions that happened on the amino group, hydroxyl group, or both amino group and hydroxyl group to create modified chitosan-based organic materials. Finally, the problems that still need to be solved and probable future areas for study are discussed.


Assuntos
Quitosana , Solubilidade , Quitosana/química , Biopolímeros/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
20.
Biomacromolecules ; 25(9): 5437-5453, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39153005

RESUMO

Climate change and environmental pollution have underscored the urgency for more sustainable alternatives in synthetic polymer production. Nature's repertoire of biopolymers with excellent multifaceted properties alongside biodegradability could inspire next-generation innovative green polymer fabrication routes. Stimuli-induced processing, driven by changes in environmental factors, such as pH, ionic strength, and mechanical forces, plays a crucial role in natural polymeric self-assembly process. This perspective aims to close the gap in understanding biopolymer formation by highlighting the essential role of stimuli triggers in facilitating the bottom-up fabrication, allowing for the formation of intricate hierarchical structures. In particular, this perspective will delve into the stimuli-responsive processing of high-performance biopolymers produced by mussels, caddisflies, velvet worms, sharks, whelks, and squids, which are known for their robust mechanical properties, durability, and wet adhesion capabilities. Finally, we provide an overview of current advancements and challenges in understanding stimuli-induced natural formation pathways and their translation to biomimetic materials.


Assuntos
Materiais Biomiméticos , Animais , Biopolímeros/química , Materiais Biomiméticos/química , Concentração de Íons de Hidrogênio , Bivalves/química
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