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1.
ACS Omega ; 9(35): 37002-37011, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39246460

RESUMO

Seaweed-derived alginate shows promise in the textile industry as a sustainable alternative to synthetic and natural materials. However, challenges arise due to its low mechanical strength. We addressed this limitation by sustainably extracting alginates from European brown algae and employing novel manufacturing methods. Using natural cross-linkers, such as chitosan, ferulic acid, and citric acid, we have successfully modulated the mechanical properties of alginate fibers. Mechanical properties of ferulic acid and citric acid-cross-linked alginate solutions were spinnable, producing fibers with a diameter of 73-75 µm. Ferulic acid cross-linked alginate fibers exhibited stiffness, with a tensile strength of 52.97 MPa and a strain percentage of 20.77, mechanical properties comparable to those of wool, polyester, and rayon. In contrast, citric acid-cross-linked fibers showed partial elasticity, with a tensile strength of 14.35 MPa and a strain percentage of 45.53, comparable to those of nylon. This ability to control the mechanical properties of seaweed-derived fibers represents a significant advancement for their application in sustainable textiles and the fashion industry.

2.
J Food Sci ; 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39289790

RESUMO

This study aimed to investigate the effects of acid or alkali modification of isolated cassava starch (ICS) on its physicochemical properties. Acetic acid concentrations of 5%, 10%, and 20% v/v (0.87, 1.73, and 3.46 M, respectively) and calcium hydroxide concentrations of 0.15%, 0.20%, and 0.30% w/w (0.02, 0.025, and 0.04 M, respectively) were tested independently and compared with untreated isolated starch. The scanning electron microscope (SEM) shows starches with polyhedral and semispherical shapes; these modifications do not change the surface of the starch granules. Nanocrystals with orthorhombic crystal structure were extracted from ICS. Transmission electron microscopy (TEM) shows crystallites with a size (two-dimensional) of 20 ± 5 nm in length and 10 ± 2 nm in width and reveals that this starch contains nanocrystals with orthorhombic crystal structure. The X-ray patterns show that these nanocrystals are unaffected by acidic or alkaline treatments. The Ca+2 and CH3COO- ions do not interact with these nanocrystals. The alkaline treatment only affects the gelatinization temperature at a Ca(OH)2 concentration of 0.30%. Low concentrations of acidic and alkaline treatments affect the ability of cassava starch to absorb water and reduce the peak and final viscosity. The infrared spectra show that the modifications lead to C-H and C═C bond formations. ICS-B 0.30 can modify the amorphous regions of the starch, and the acid treatment leads to acetylation, which was confirmed by the presence of an IR band at 1740 cm-1.

3.
Plants (Basel) ; 13(16)2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39204671

RESUMO

Vegetative desiccation tolerance has evolved within the genera Craterostigma and Lindernia. A centre of endemism and diversification for these plants appears to occur in ancient tropical montane rainforests of east Africa in Kenya and Tanzania. Lindernia subracemosa, a desiccation-sensitive relative of Craterostigma plantagineum, occurs in these rainforests and experiences adequate rainfall and thus does not require desiccation tolerance. However, sharing this inselberg habitat, another species, Lindernia brevidens, does retain vegetative desiccation tolerance and is also related to the resurrection plant C. plantagineum found in South Africa. Leaf material was collected from all three species at different stages of hydration: fully hydrated (ca. 90% relative water content), half-dry (ca. 45% relative water content) and fully desiccated (ca. 5% relative water content). Cell wall monosaccharide datasets were collected from all three species. Comprehensive microarray polymer profiling (CoMPP) was performed using ca. 27 plant cell-wall-specific antibodies and carbohydrate-binding module probes. Some differences in pectin, xyloglucan and extension epitopes were observed between the selected species. Overall, cell wall compositions were similar, suggesting that wall modifications in response to vegetative desiccation involve subtle cell wall remodelling that is not reflected by the compositional analysis and that the plants and their walls are constitutively protected against desiccation.

4.
ACS Omega ; 9(29): 31438-31454, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39072051

RESUMO

Identification of proteins involved in cell wall matrix polysaccharide biosynthesis is crucial to understand plant cell wall biology. We utilized in vivo cross-linking and immunoprecipitation with cell wall antibodies that recognized xyloglucan, xylan, mannan, and homogalacturonan to capture proteins associated with matrix polysaccharides in Arabidopsis protoplasts. The use of cross-linkers allowed us to capture proteins actively associated with cell wall polymers, including those directly interacting with glycans via glycan-protein (GP) cross-linkers and those associated with proteins linked to glycans via a protein-protein (PP) cross-linker. Immunoprecipitations led to the identification of 65 Arabidopsis protein IDs localized in the Golgi, ER, plasma membrane, and others without subcellular localization data. Among these, we found several glycosyltransferases directly involved in polysaccharide synthesis, along with proteins related to cell wall modification and vesicle trafficking. Protein interaction networks from DeepAraPPI and AtMAD databases showed interactions between various IDs, including those related to cell-wall-associated proteins and membrane/vesicle trafficking proteins. Gene expression and coexpression analyses supported the presence and relevance of the proteins to the cell wall processes. Reverse genetic studies using T-DNA insertion mutants of selected proteins revealed changes in cell wall composition and saccharification, further supporting their potential roles in cell wall biosynthesis. Overall, our approach represents a novel approach for studying cell wall polysaccharide biosynthesis and associated proteins, providing advantages over traditional immunoprecipitation techniques. This study provides a list of putative proteins associated with different matrix polysaccharides for further investigation and highlights the complexity of cell wall biosynthesis and trafficking within plant cells.

5.
Carbohydr Polym ; 339: 122248, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823916

RESUMO

Arabinoxylan is a major hemicellulose in the sugarcane plant cell wall with arabinose decorations that impose steric restrictions on the activity of xylanases against this substrate. Enzymatic removal of the decorations by arabinofuranosidases can allow a more efficient arabinoxylan degradation by xylanases. Here we produced and characterized a recombinant Bifidobacterium longum arabinofuranosidase from glycoside hydrolase family 43 (BlAbf43) and applied it, together with GH10 and GH11 xylanases, to produce xylooligosaccharides (XOS) from wheat arabinoxylan and alkali pretreated sugarcane bagasse. The enzyme synergistically enhanced XOS production by GH10 and GH11 xylanases, being particularly efficient in combination with the latter family of enzymes, with a degree of synergism of 1.7. We also demonstrated that the enzyme is capable of not only removing arabinose decorations from the arabinoxylan and from the non-reducing end of the oligomeric substrates, but also hydrolyzing the xylan backbone yielding mostly xylobiose and xylose in particular cases. Structural studies of BlAbf43 shed light on the molecular basis of the substrate recognition and allowed hypothesizing on the structural reasons of its multifunctionality.


Assuntos
Bifidobacterium longum , Celulose , Endo-1,4-beta-Xilanases , Glucuronatos , Glicosídeo Hidrolases , Oligossacarídeos , Saccharum , Xilanos , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosídeo Hidrolases/química , Glucuronatos/metabolismo , Glucuronatos/química , Endo-1,4-beta-Xilanases/metabolismo , Endo-1,4-beta-Xilanases/química , Xilanos/metabolismo , Xilanos/química , Saccharum/química , Saccharum/metabolismo , Celulose/química , Celulose/metabolismo , Bifidobacterium longum/enzimologia , Bifidobacterium longum/metabolismo , Hidrólise , Especificidade por Substrato , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/química , Dissacarídeos
6.
Front Immunol ; 15: 1352306, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464511

RESUMO

Introduction: The lncRNAs (long non-coding RNAs) are the most diverse group of non-coding RNAs and are involved in most biological processes including the immune response. While some of them have been recognized for their influence on the regulation of inflammatory activity, little is known in the context of infection by Brucella abortus, a pathogen that presents significant challenges due to its ability to manipulate and evade the host immune system. This study focuses on characterize the expression profile of LincRNA-cox2, Lethe, lincRNA-EPS, Malat1 and Gas5 during infection of macrophages by B. abortus. Methods: Using public raw RNA-seq datasets we constructed for a lncRNA expression profile in macrophages Brucella-infected. In addition, from public RNA-seq raw datasets of RAW264.7 cells infected with B. abortus we constructed a transcriptomic profile of lncRNAs in order to know the expression of the five immunomodulating lncRNAs studied here at 8 and 24 h post-infection. Finally, we performed in vitro infection assays in RAW264.7 cells and peritoneal macrophages to detect by qPCR changes in the expression of these lncRNAs at first 12 hours post infection, a key stage in the infection cycle where Brucella modulates the immune response to survive. Results: Our results demonstrate that infection of macrophages with Brucella abortus, induces significant changes in the expression of LincRNA-Cox2, Lethe, LincRNA-EPS, Gas5, and Malat1. Discussion: The change in the expression profile of these immunomodulatory lncRNAs in response to infection, suggest a potential involvement in the immune evasion strategy employed by Brucella to facilitate its intracellular survival.


Assuntos
Brucelose , RNA Longo não Codificante , Animais , Camundongos , Brucella abortus/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ciclo-Oxigenase 2/metabolismo , Macrófagos
7.
Rev Colomb Psiquiatr (Engl Ed) ; 52(4): 305-313, 2023.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-38065663

RESUMO

INTRODUCTION: Mild Cognitive Impairment (MCI) is common in Parkinson's Disease (PD). Few studies have compared the Health-Related Quality of Life (HRQoL) in patients with and without MCI due to PD (PD-MCI), and its correlation to patients' subjective cognitive and communicative difficulties has not been explored. OBJECTIVE: We aimed to compare HRQoL in PD-MCI and PD without MCI (PD-nMCI), and explore its possible relationship to subjective cognitive and communicative complaints. METHODS: We included 29 PD-nMCI and 11 PD-MCI patients. The HRQoL was assessed with the Parkinson's Disease Questionnaire-39 (PDQ-39): its Cognition dimension was used as a measure of subjective cognitive complaints, its Communication dimension for subjective communicative complaints, and the summary index (PDQ-39 SI) as an indicator of HRQoL. Non-parametric partial correlations between the Cognition and Communication dimensions, and the adjusted PDQ-39 SI were conducted. RESULTS: PD-MCI patients had greater subjective cognitive and communicative complaints and worse HRQoL than PD-nMCI patients. In the PD-MCI group, both subjective cognitive and communicative complaints exhibited significant direct correlations with the adjusted HRQoL scores. CONCLUSIONS: HRQoL seems to be affected in PD-MCI, and it might be influenced by greater subjective cognitive and communicative complaints. Including patient-reported outcome measures of HRQoL, and providing cognitive and speech rehabilitation, as well as psychotherapeutic strategies to face these deficits can enhance the patient-centred approach in PD.


Assuntos
Disfunção Cognitiva , Doença de Parkinson , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Qualidade de Vida/psicologia , Testes Neuropsicológicos , Disfunção Cognitiva/etiologia , Cognição , Comunicação
8.
ACS Sustain Chem Eng ; 11(39): 14323-14333, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37799817

RESUMO

Cocoa pod husks (CPHs) represent an underutilized component of the chocolate manufacturing process. While industry's current focus is understandably on the cocoa beans, the husks make up around 75 wt % of the fruit. Previous studies have been dominated by the carbohydrate polymers present in CPHs, but this work highlights the presence of the biopolymer lignin in this biomass. An optimized organosolv lignin isolation protocol was developed, delivering significant practical improvements. This new protocol may also prove to be useful for agricultural waste-derived biomasses in general. NMR analysis of the high quality lignin led to an improved structural understanding, with evidence provided to support deacetylation of the lignin occurring during the optimized pretreatment. Chemical transformation, using a tosylation, azidation, copper-catalyzed click protocol, delivered a modified lignin oligomer with an organophosphorus motif attached. Thermogravimetric analysis was used to demonstrate the oligomer's potential as a flame-retardant. Preliminary analysis of the other product streams isolated from the CPHs was also carried out.

9.
Plants (Basel) ; 12(10)2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37653894

RESUMO

Plant cell wall biosynthesis is a complex process that requires proteins and enzymes from glycan synthesis to wall assembly. We show that disruption of At3g50120 (DUF247-1), a member of the DUF247 multigene family containing 28 genes in Arabidopsis, results in alterations to the structure and composition of cell wall polysaccharides and reduced growth and plant size. An ELISA using cell wall antibodies shows that the mutants also exhibit ~50% reductions in xyloglucan (XyG), glucuronoxylan (GX) and heteromannan (HM) epitopes in the NaOH fraction and ~50% increases in homogalacturonan (HG) epitopes in the CDTA fraction. Furthermore, the polymer sizes of XyGs and GXs are reduced with concomitant increases in short-chain polymers, while those of HGs and mHGs are slightly increased. Complementation using 35S:DUF247-1 partially recovers the XyG and HG content, but not those of GX and HM, suggesting that DUF247-1 is more closely associated with XyGs and HGs. DUF247-1 is expressed throughout Arabidopsis, particularly in vascular and developing tissues, and its disruption affects the expression of other gene members, indicating a regulatory control role within the gene family. Our results demonstrate that DUF247-1 is required for normal cell wall composition and structure and Arabidopsis growth.

10.
Nanoscale Adv ; 5(18): 4728-4734, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37705781

RESUMO

Skyrmions can be envisioned as bits of information that can be transported along nanoracetracks. However, temperature, defects, and/or granularity can produce diffusion, pinning, and, in general, modification in their dynamics. These effects may cause undesired errors in information transport. We present simulations of a realistic system where both the (room) temperature and sample granularity are taken into account. Key feasibility magnitudes, such as the success probability of a skyrmion traveling a given distance along the racetrack, are calculated. The results are evaluated in terms of the eventual loss of skyrmions by pinning, destruction at the edges, or excessive delay due to granularity. The model proposed is based on the Fokker-Planck equation resulting from Thiele's rigid model for skyrmions. The results could serve to establish error detection criteria and, in general, to discern the dynamics of skyrmions in realistic situations.

11.
Toxins (Basel) ; 15(9)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37755962

RESUMO

Toxin/antitoxin (TA) systems have been scarcely studied in Brucella abortus, the causative agent of brucellosis, which is one of the most prevalent zoonotic diseases worldwide. In this study, the roles of a putative type II TA system composed by a Zinc-dependent metalloproteinase (ZnMP) and a transcriptional regulator HTH-Xre were evaluated. The deletion of the open reading frame (ORF) BAB1_0270, coding for ZnMP, used to produce a mutant strain, allowed us to evaluate the survival and gene expression of B. abortus 2308 under oxidative conditions. Our results showed that the B. abortus mutant strain exhibited a significantly reduced capacity to survive under hydrogen peroxide-induced oxidative stress. Furthermore, this mutant strain showed a decreased expression of genes coding for catalase (katE), alkyl hydroperoxide reductase (ahpC) and transcriptional regulators (oxyR and oxyR-like), as well as genes involved in the general stress response, phyR and rpoE1, when compared to the wild-type strain. These findings suggest that this type II ZnMP/HTH-Xre TA system is required by B. abortus to resist oxidative stress. Additionally, previous evidence has demonstrated that this ZnMP also participates in the acidic stress resistance and virulence of B. abortus 2308. Therefore, we propose a hypothetical regulatory function for this ZnMP/HTH-Xre TA system, providing insight into the stress response and its potential roles in the pathogenesis of B. abortus.


Assuntos
Brucella abortus , Metaloporfirinas , Zinco , Animais , Camundongos , Brucella abortus/genética , Brucella abortus/metabolismo , Virulência/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estresse Oxidativo , Metaloproteases/metabolismo , Camundongos Endogâmicos BALB C
12.
PLoS One ; 18(9): e0288006, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37751460

RESUMO

Despite that more than one hundred vaccines against SARS-CoV-2 have been developed and that some of them were evaluated in clinical trials, the latest results revealed that these vaccines still face great challenges. Among the components of the virus, the N-protein constitutes an attractive target for a subunit vaccine because it is the most abundant, highly conserved and immunogenic protein. In the present work, a chimeric protein (N-CD protein) was constructed by the fusion of the N-protein to the extracellular domain of human CD154 as the molecular adjuvant. HEK-293 cells were transduced with lentiviral vector bearing the N-CD gene and polyclonal cell populations were obtained. The N-CD protein was purified from cell culture supernatant and further characterized by several techniques. Immunogenicity studies in mice and non-human primates showed the N-CD protein induced high IgG titers in both models after two doses. Moreover, overall health monitoring of non-human primates demonstrated that animals were healthy during 228 days after first immunization. Data obtained support further investigation in order to develop this chimeric protein as vaccine candidate against COVID-19 and other coronavirus diseases.


Assuntos
COVID-19 , Vacinas , Humanos , Animais , Camundongos , SARS-CoV-2/genética , COVID-19/prevenção & controle , Células HEK293 , Vacinas contra COVID-19 , Nucleocapsídeo , Ligante de CD40/genética , Proteínas Recombinantes de Fusão/genética
13.
Front Immunol ; 14: 1186368, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37575242

RESUMO

Background: Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen that causes gastrointestinal infections, ranging from acute diarrhea and dysentery to life-threatening diseases such as Hemolytic Uremic Syndrome. Currently, a vaccine to prevent STEC infection is an unmet medical need. Results: We developed a chimeric protein-based vaccine targeting seven virulence factors of STEC, including the Stx2B subunit, Tir, Intimin, EspA, Cah, OmpT, and AggA proteins. Immunization of mice with this vaccine candidate elicited significant humoral and cellular immune responses against STEC. High levels of specific IgG antibodies were found in the serum and feces of immunized mice. However, specific IgA antibodies were not detected in either serum or feces. Furthermore, a significantly higher percentage of antigen-specific CD4+ T cells producing IFN-γ, IL-4, and IL-17 was observed in the spleens of immunized mice. Notably, the immunized mice showed decreased shedding of STEC O157:H7 and STEC O91:H21 strains and were protected against weight loss during experimental infection. Additionally, infection with the STEC O91:H21 strain resulted in kidney damage in control unimmunized mice; however, the extent of damage was slightly lower in immunized mice. Our findings suggest that IgG antibodies induced by this vaccine candidate may have a role in inhibiting bacterial adhesion and complement-mediated killing. Conclusion: This study provides evidence that IgG responses are involved in the host defense against STEC. However, our results do not rule out that other classes of antibodies also participate in the protection against this pathogen. Additional work is needed to improve the protection conferred by our vaccine candidate and to elucidate the relevant immune responses that lead to complete protection against this pathogen.


Assuntos
Infecções por Escherichia coli , Escherichia coli Shiga Toxigênica , Vacinas , Animais , Camundongos , Imunoglobulina G , Formação de Anticorpos , Proteínas Recombinantes de Fusão
14.
Front Med (Lausanne) ; 10: 1155751, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37215733

RESUMO

Vibrio cholerae is the causative agent of cholera, a highly contagious diarrheal disease affecting millions worldwide each year. Cholera is a major public health problem, primarily in countries with poor sanitary conditions and regions affected by natural disasters, where access to safe drinking water is limited. In this narrative review, we aim to summarize the current understanding of the evolution of virulence and pathogenesis of V. cholerae as well as provide an overview of the immune response against this pathogen. We highlight that V. cholerae has a remarkable ability to adapt and evolve, which is a global concern because it increases the risk of cholera outbreaks and the spread of the disease to new regions, making its control even more challenging. Furthermore, we show that this pathogen expresses several virulence factors enabling it to efficiently colonize the human intestine and cause cholera. A cumulative body of work also shows that V. cholerae infection triggers an inflammatory response that influences the development of immune memory against cholera. Lastly, we reviewed the status of licensed cholera vaccines, those undergoing clinical evaluation, and recent progress in developing next-generation vaccines. This review offers a comprehensive view of V. cholerae and identifies knowledge gaps that must be addressed to develop more effective cholera vaccines.

15.
Int J Biol Macromol ; 236: 123981, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36907301

RESUMO

Maize grains are composed of the pericarp, endosperm, and germ. Consequently, any treatment, such as electromagnetic fields (EMF) must alter these components, which in turn alters the physicochemical properties of the grain. Since starch is a major component of corn grain, and given the great industrial importance of starch, this study investigates how EMF affects the physicochemical properties of starch. Mother seed were exposed to three different intensities 23, 70, and 118 µT for 15 days. Except for a slight porosity on the surface of the starch of the grains of plants exposed to higher EMF, the starch showed no morphological differences between the different treatments and the control (according to scanning electron microscopy). The X-ray patterns showed that the orthorhombic structure was kept constant, unaffected by the intensity of EMF. However, the pasting profile of starch was affected, and a decrease in the peak viscosity was obtained when the intensity of EMF increased. In contrast to the control plants, FTIR shows characteristic bands which can be attributed to the stretching of the CO bonds at wave number 1.711 cm-1. EMF can be considered a physical modification of starch.


Assuntos
Amido , Zea mays , Amido/química , Zea mays/química , Campos Eletromagnéticos , Sementes/química , Endosperma
16.
Biology (Basel) ; 12(3)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36979076

RESUMO

COVID-19, an infection produced by the SARS-CoV-2 virus in humans, has rapidly spread to become a high-mortality pandemic. SARS-CoV-2 is a single-stranded RNA virus characterized by infecting epithelial cells of the intestine and lungs, binding to the ACE2 receptor present on epithelial cells. COVID-19 treatment is based on antivirals and antibiotics against symptomatology in addition to a successful preventive strategy based on vaccination. At this point, several variants of the virus have emerged, altering the effectiveness of treatments and thereby attracting attention to several alternative therapies, including immunobiotics, to cope with the problem. This review, based on articles, patents, and an in silico analysis, aims to address our present knowledge of the COVID-19 disease, its symptomatology, and the possible beneficial effects for patients if probiotics with the characteristics of immunobiotics are used to confront this disease. Moreover, two probiotic strains, L. fermentum UCO-979C and L. rhamnosus UCO-25A, with different effects demonstrated at our laboratory, are emphasized. The point of view of this review highlights the possible benefits of probiotics, particularly those associated with immunomodulation as well as the production of secondary metabolites, and their potential targets during SARS-CoV-2 infection.

17.
Int J Biol Macromol ; 226: 434-442, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36502944

RESUMO

Applications of natural fibres are expanding, and sustainable alternatives are needed to support this growing demand. We investigated the production of fibres using alginates from Saccharina latissima (SAC), Laminaria digitata (LAM), Sacchoriza polyschides (SACC), and Himanthalia spp. (HIM). After extraction (3 % w/v biomass) using a sustainable protocol based on citric acid, crude alginate represented 61-65 % of the biomass dry weight for SAC and LAM, and 34-41 % for SACC and HIM when experiments were performed at small scale (1.5 g of starting material). Interestingly, scaling-up extraction (60 g of starting material) decreased yields to 26-30 %. SAC and LAM alginates had the highest M/G (mannuronic acid/guluronic acid) ratios and molecular weights when compared to those from SACC and HIM (M/G:1.98 and 2.23, MW: 302 and 362 kDa, vs 1.83 and 1.86, 268 and 168 kDa). When the four types of alginates were tested for spinning fibres cross-linked with CaCl2, only SAC and LAM alginates produced fibres. These fibres showed no clumps or cracks under stretching action and presented a similar Young's modulus (2.4 and 2.0 GPa). We have demonstrated that alginate extracted from S. latissima and L. digitata can be successfully spun into functional fibres cross-linked with CaCl2.


Assuntos
Laminaria , Phaeophyceae , Alginatos , Cloreto de Cálcio , Ácidos Hexurônicos
18.
Molecules ; 27(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36296599

RESUMO

Acacia spp. are invasive in Southern Europe, and their high propagation rates produce excessive biomass, exacerbating wildfire risk. However, lignocellulosic biomass from Acacia spp. may be utilised for diverse biorefinery applications. In this study, attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), high-performance anion-exchange chromatography pulsed amperometric detection (HPAEC-PAD) and lignin content determinations were used for a comparative compositional characterisation of A. dealbata, A. longifolia and A. melanoxylon. Additionally, biomass was treated with three white-rot fungi species (Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor), which preferentially degrade lignin. Our results showed that the pre-treatments do not significantly alter neutral sugar composition while reducing lignin content. Sugar release from enzymatic saccharification was enhanced, in some cases possibly due to a synergy between white-rot fungi and mild alkali pretreatments. For example, in A. dealbata stems treated with alkali and P. ostreatus, saccharification yield was 702.3 nmol mg-1, which is higher than the samples treated only with alkali (608.1 nmol mg-1), and 2.9-fold higher than the non-pretreated controls (243.9 nmol mg-1). By characterising biomass and pretreatments, generated data creates value for unused biomass resources, contributing to the implementation of sustainable biorefining systems. In due course, the generated value will lead to economic incentives for landowners to cut back invasive Acacia spp. more frequently, thus reducing excess biomass, which exacerbates wildfire risk.


Assuntos
Acacia , Lignina , Lignina/química , Acacia/química , Trametes/metabolismo , Biomassa , Álcalis , Açúcares
19.
Front Plant Sci ; 13: 926300, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937377

RESUMO

Ester-linked hydroxycinnamic acids ferulic acid (FA) and para-coumaric acid (p-CA) play important roles in crosslinking within cell wall arabinoxylans (AX) and between AX and lignin in grass cell walls. The addition of hydroxycinnamates to AX, is mediated by the Mitchell clade of BAHD acyl-coenzyme A-utilizing transferases. Overexpression of OsAT10 (a Mitchell clade BAHD acyl transferase) in rice, has previously been shown to increase p-CA content in AX in leaves and stems, leading to increased cell wall digestibility, potentially associated with a concomitant decrease in FA content. To investigate the physiological role of OsAT10 we established CRISPR/Cas9 rice knock-out mutants devoid of OsAT10. Our analysis of hydroxycinnamic acid content in wild type plants revealed that AX associated p-CA is found almost exclusively in rice husks, with very little found in other tissues. Mutant plants were essentially devoid of ester-linked p-CA associated with AX, indicating that OsAT10 represents the major enzyme responsible for the addition of p-CA to arabinoxylan in rice plants. We found no change in the digestibility of rice husk lacking AX-associated p-CA, suggesting that the changes in digestibility seen in OsAT10 overexpressing plants were solely due to compensatory decreases in AX-associated FA.

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