Mucilage is a gelatinous and sticky hydrophilic polysaccharide released from epidermal cells of seed coat after the hydration of mature seeds and is composed primarily of unbranched ...rhamnogalacturonan I (RG-I). In this study, we produced a recombinant endo-RG-I hydrolase from Aspergillus aculeatus (AaRhgA) in the fission yeast Schizosaccharomyces pombe and examined its substrate preference for pyridylaminated (PA) RG-I with the various degrees of polymerization (DP). Recombinant AaRhgA requires PA-RG-I with a DP of 10 or higher for its hydrolase activity. We heterologously expressed the AarhgA gene under the strong constitutive promoter, cauliflower mosaic virus 35S promoter, in Arabidopsis thaliana. In a series of biochemical analyses of each mucilage fraction released from the water-imbibed seeds of the transgenic plants, we found the enhanced deposition of the transparent mucilage layer that existed in the peripheral regions of the adherent mucilage and was not stained with ruthenium red. This study demonstrated the feasibility of manipulating the mucilage organization by heterologous expression of the endo-RG-I hydrolase.
•A production system for recombinant AaRhgA enzyme in S. pombe was established.•Substrate preference for PA-RG-I with various DP was demonstrated.•AarhgA was heterologously expressed under the CaMV promoter in A. thaliana.•Enhanced deposition of the transparent mucilage layer was revealed in transgenic plants.
•The metabolome and transcriptome of B. juncea roots under Cd stress were analyzed.•A total of 104 DEGs related to lignin and pectin synthesis were screened out.•Eight DEMs related to lignin and ...pectin synthesis were observed.•Synthesis of lignin and pectin plays vital roles in response to Cd stress.
Brassica juncea possesses the capacity to tolerate and accumulate various heavy metals. The cell wall is the first barrier to inhibit heavy metals into the plant cytoplasm. In this work, we investigated the effects of cadmium (Cd) exposure on lignin and pectin synthesis in B. juncea roots by integrated metabolomic and transcriptomic analyses. The findings showed that the contents of lignin and pectin, the activities of phenylalanine ammonia-lyase, laccase, superoxide dismutase, and peroxidase significantly increased following Cd stress, while the activity of pectinesterase decreased. Transcriptome analysis revealed 94 (20 upregulated and 74 downregulated) and 10 (7 upregulated and 3 downregulated) differentially expressed genes in the phenylpropane metabolic pathway and galactose metabolic pathway, respectively. Additionally, metabolomic analyses revealed differentially expressed metabolites related to lignin and pectin synthesis, including N-acetyl-D-phenylalanine, sinapyl alcohol, eugenol, galactosylglycerol, 2-keto-3-deoxy-D-gluconic acid, sucrose, and lactose 6-phosphate, implying lignin and pectin in cell wall play vital roles in Cd detoxification. Our results offer a molecular-scale perspective for further exploring the adaptability in Cd-exposed plants.
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Methyl jasmonate (MeJA), a crucial phytohormone, which plays an important role in resistance to Cadmium (Cd) stress. The cell wall (CW) of root system is the main location of Cd and plays a key role ...in resistance to Cd toxicity. However, the mechanism effect of MeJA on the CW composition and Cd accumulation remain unclear. In this study, the contribution of MeJA in regulating CW structure, pectin composition and Cd accumulation was investigated in Cosmos bipinnatus. Phenotypic results affirm MeJA's significant role in reducing Cd-induced toxicity in C. bipinnatus. Notably, MeJA exerts a dual impact, reducing Cd uptake in roots while increasing Cd accumulation in the CW, particularly bound to pectin. The molecular structure of pectin, mainly uronic acid (UA), correlates positively with Cd content, consistent in HC1 and cellulose, emphasizing UA as pivotal for Cd binding. Furthermore, MeJA modulates pectin methylesterase (PME) activity under Cd stress, influencing pectin's molecular structure and homogalacturonan (HG) content affecting Cd-binding capacity. Chelate-soluble pectin (CSP) within soluble pectins accumulates a substantial Cd proportion, with MeJA regulating both UA content and the minor component 3-deoxy-oct-2-ulosonic acid (Kdo) in CSP. The study delves into the intricate regulation of pectin monosaccharide composition under Cd stress, revealing insights into the CW's physical defense and Cd binding. In summary, this research provides novel insights into MeJA-specific mechanisms alleviating Cd toxicity in C. bipinnatus, shedding light on complex interactions between MeJA, and Cd accumulation in CW pectin polysaccharide.
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•MeJA reduces root Cd uptake by increasing cellulose and neutral sugars content.•MeJA increases Cd in root cell walls by regulating pectin properties.•Uronic acid (UA) content is crucial for Cd accumulation in root cell walls.•PME activity influences Cd accumulation by impacting UA, LMP, and CSP content.
SYNOPSIS: In Cosmos bipinnatus, MeJA increased Cd in CW and modulated pectin composition, revealing valuable insights into the mechanism by which MeJA mitigates Cd toxicity and regulates Cd accumulation in plants.
Different degree of esterification (DE) and molecular weight (Mw) of apple pomace pectin (APP) were evaluated for the effect on lipid digestibility. APP was isolated from variety “Blanca de Asturias” ...by acidic extraction to obtain pectin with 66% of DE, and 348 kDa Mw. APP was de-esterified with pectinmethylesterase (PME) obtaining APP with DE of 57, 42, and 39%. APP was depolymerized by endo-polygalacturonase (PG) or pectate lyase (PL), and three modified APP fractions were obtained with Mw of 309, 166, and 162 kDa or 241, 205, and 184 kDa for PG-APP or PL-APP fractions, respectively. A considerable reduction in the composition of neutral sugars was observed in the modified samples, which is related to the reduction of the branched region of the pectin. Oil-in-water emulsions prepared with 2% (w/w) of different APP samples were shear thinning and viscosity was 2–20 times higher in pectin added emulsions. Inhibition of lipid digestibility measured in a multiple stage in vitro model showed that APP and modified APP with higher DE significantly reduced lipid digestibility by 25%. The results contribute to the design of higher fat foods and putative higher consumer acceptability. The addition of pectin with certain structural characteristics, can reduce the degree of lipid digestibility, that may help mitigate public health problems such as obesity.
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•Different DE and Mw of APP were obtained by enzymatic modification technique.•Modified APP with higher DE significantly reduced lipid digestibility by 25%.•RG-I fractions of APP showed to contribute to the inhibitory effect on lipid digestibility.
Bacterial cellulose (BC) as a never-dried biopolymer synthesized in abundance by Gluconacetobacter xylinus is in a pure form which requires no intensive processing to remove unwanted impurities and ...contaminants such as lignin, pectin and hemicellulose. In contrast to plant cellulose, BC, with several remarkable physical properties, can be grown to any desired shape and structure to meet the needs of different applications. BC has been commercialized as diet foods, filtration membranes, paper additives, and wound dressings. This review article presents an overview of BC structure, biosynthesis, applications, state-of-the-art advances in enhancing BC production, and its material properties through the investigations of genetic regulations, fermentation parameters, and bioreactor design. In addition, future prospects on its applications through chemical modification as a new biologically active derivative will be discussed.
Environmental pollution remains a constant challenge due to the indiscriminate use of fossil fuels, mining activities, chemicals, drugs, aromatic compounds, pesticides, etc. Many emerging pollutants ...with no fixed standards for monitoring and control are being reported. These have adverse impacts on human life and the environment around us. This alarms the wastewater management towards developing materials that can be used for bulk water treatment and are easily available, low cost, non-toxic and biodegradable.
Waste biomass like pectin is extracted from fruit peels which are a discarded material. It is used in pharmaceutical and nutraceutical applications but its application as a material for water treatment is very limited in literature. The scientific gap in literature review reports are evident with discussion only on pectin based hydrogels or specific pectin derivatives for some applications. This review focuses on the chemistry, extraction, functionalization and production of pectin derivatives and their applications in water treatment processes. Pectin functionalized derivatives can be used as a flocculant, adsorbent, nano biopolymer, biochar, hybrid material, metal-organic frameworks, and scaffold for the removal of heavy metals, ions, toxic dyes, and other contaminants. The huge quantum of pectin biomass may be explored further to strengthen environmental sustainability and circular economy practices.
Remedy of contaminated water from fruits and its waste part. Display omitted
Some of conventional wastewater disinfectants can have a harmful influence on the environment as well as human health. The aim of this investigation was synthesis and characterizes ecofriendly ...pectin/hydroxyethyl cellulose (HEC)/clay and pectin/HEC/clay incorporated with titanium dioxide nanoparticles (TiO2NPs) and use the prepared bionanocomposite as microbial disinfectants for real wastewater. Pectin/HEC/clay and pectin/HEC/clay/TiO2 bionanocomposite were characterized by various methods including X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier-transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). Mechanical properties and water vapor permeability (WVP) were carried out. The results of SEM showed that, the prepared bionanocomposite had a smooth surface. Additionally, TiO2 nanoparticles to the pectin/HEC/clay composites may lead to changes in the FTIR spectrum. The intensity of XRD peaks indicated that, TiO2NPs was small size crystallite. TGA illustrated that pectin has moderate thermal stability, while HEC generally exhibits good thermal stability. The TEM showed that, TiO2 nanoparticles have diameters <25 nm. On the other hand, antimicrobial activities of pectin/HEC/clay against Escherichia coli (E. coli), Staphylococcus aureus and Candida albicans have been enhanced by adding TiO2NPs. The minimum inhibitory concentration (MIC) of pectin/HEC/clay/TiO2 against E. coli was 200 mg/mL. Moreover, complete eradication of E. coli, Salmonella and Candida spp. from real wastewater was observed by using pectin/HEC/clay/TiO2 bionanocomposite. Finally, it can be concluded that, the synthesized bionanocomposite is environmentally friendly and considered an excellent disinfectant matter for removal of the microbial pathogens from wastewater to safely reuse.
In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, ...interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil–water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.
•The flexibility of ultrasonic modified SBP molecules was enhanced.•Ultrasonic modification increased the diffusion rate of SBP at oil-water interface.•Modified SBP molecules were easier to unfold and rearrange at oil-water interface.•Emulsifying properties of modified SBP were dominated by ultrasonic intensity.•Modified SBP showed better emulsifying stability under environmental stresses.
The great structural and functional diversity supports polysaccharides as favorable candidates for new drug development. Previously we reported that a drug candidate pectin-like natural ...polysaccharide, RN1 might target galectin-3 (Gal-3) to impede pancreatic cancer cell growth in vivo. However, the quality control of polysaccharide-based drug research faces great challenges due to the heterogeneity. A potential solution is to synthesize structurally identified subfragments of this polysaccharide as alternatives. In this work, we took RN1 as an example, and synthesized five subfragments derived from the putative repeating units of RN1. Among them, pentasaccharide 4 showed an approximative binding affinity to Gal-3 in vitro, as well as an antiproliferative activity against pancreatic BxPC-3 cells comparable to that of RN1. Further, we scaled up pentasaccharide 4 to gram-scale in an efficient synthetic route with a 6.9 % yield from D-galactose. Importantly, pentasaccharide 4 significantly suppressed the growth of pancreatic tumor in vivo. Based on the mechanism complementarity of galactin-3 inhibitor and docetaxel, the combination administration of pentasaccharide 4 and docetaxel afforded better result. The result suggested pentasaccharide 4 was one of the functional structural domains of polysaccharide RN1 and might be a leading compound for anti-pancreatic cancer new drug development.
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In order to develop new and low cost anticoagulants as potential heparin alternatives, sulfation of a pectin-like polysaccharide from Opuntia ficus indica cladodes using SO3-DMF complex was performed ...with a significant sulfate content (7%). FTIR and NMR assays indicated that the sulfation reaction had occurred. In addition, GC–MS analyses demonstrated that sulfation was carried out on the arabinose units of native polysaccharide. Moreover, Physico-chemical characterization indicated an evident decrease of the average molecular weight (Mw) and sugar rates after sulfation. Finally, anticoagulant assays demonstrated that the anticoagulant activity was significantly enhanced by the addition of sulfate groups. Thus, sulfated polysaccharides exhibited the most potent anticoagulant activity by prolonging activated partial thromboplastin time (APTT) and thrombin time (TT).
•Pectin was isolated from Opuntia ficus indica (OFI) cladodes with yield of 24.50% from dry matter.•Chemical sulfation of extracted pectin was performed using SO3-DMF complex.•FTIR, NMR and GC–MS indicated that the sulfation reaction had occurred with a highest sulfate content of 7.04%.•Sulfated polysaccharides showed significant anticoagulant potential depending on the sulfate content.
