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Effect of temperature on mannan endo- β-1,4-mannosidase activity. The optimal temperature was determined using 0.5% locust bean gum in 0.1 M citrate-phosphate buffer, pH 4.0, in the 10-min assay.
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Mannans are key components of lignocellulose present in the hemicellulosic fraction of plant primary cell walls. Mannan endo-1,4-beta-mannosidases (1,4-beta-D-mannanases) catalyze the random hydrolysis of beta-1,4-mannosidic linkages in the main chain of beta-mannans. Biodegradation of beta-mannans by the action of thermostable mannan endo-1,4-beta...
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Mannans are one of the key polymers in hemicellulose, a major component of lignocellulose. The Mannan endo-1,4-beta-mannosidase or 1,4-beta-D-mannanase (EC 3.2.1.78), commonly named beta-mannanase, is an enzyme that can catalyze random hydrolysis of beta-1,4-mannosidic linkages in the main chain of mannans, glucomannans and galactomannans. The enzy...
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... This revealed that the ManAn had more affinity towards the GG, a galactomannan as compared to KG, a glucomannan. Similarly, Bien-Cuong et al. 38 also reported that purified mannanase of A. niger BK01 had higher affinity towards galactomannan (GG > LBG > KG). Mannanase of A. niger gr also showed higher affinity towards GG. ...
Optimized production of Aspergillus niger ATCC 26011 endo-β-mannanase (ManAn) on copra meal resulted in 2.46-fold increase (10,028 U/gds). Purified ManAn (47 kDa) showed high affinity towards guar gum (GG) as compared to konjac gum and locust bean gum with Km 2.67, 3.25 and 4.07 mg/mL, respectively. ManAn efficiently hydrolyzed GG and liberated mannooligosaccharides (MOS). Changes occurring in the rheological and compositional aspects of GG studied using Differential scanning calorimetry (DSC), Thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) revealed increased thermal stability and crystallinity of the partially hydrolyzed guar gum (PHGG). Parametric optimization of the time and temperature dependent hydrolysis of GG (1% w/v) with 100 U/mL of ManAn at 60 °C and pH: 5.0 resulted in 12.126 mg/mL of mannotetraose (M4) in 5 min. Enhanced growth of probiotics Lactobacilli and production of short chain fatty acids (SCFA) that inhibited enteropathogens, confirmed the prebiotic potential of PHGG and M4.
... Among them, lysine-rich extensin forms a positively charged scaffold in the cell plate that can provide an ordered deposition template for new cross walls during cytoplasmic division [54]. Mannan (endo-1,4-β-mannosidase) is a key component of lignocellulose present in the hemicellulose fraction of the primary plant cell wall [55], and its production is associated with cell wall synthesis. Arabinogalactan proteins play an important role in cell wall formation [56]. ...
Chenopodium ambrosioides L. is an invasive plant native to the Neotropics that has seriously threatened the ecological security of China, and allelopathy is one of the mechanisms underlying its successful invasion. Maize (Zea mays L.) and soybean (Glycine max (L.) Merr.), as the main food crops, are usually affected by C. ambrosioides in their planting areas. The purpose of this study was to investigate the ultrastructure, autophagy, and release-related gene expression of receptor plant root border cells (RBCs) after exposure to volatile oil from C. ambrosioides and its main component α-terpene, which were studied using maize and soybean as receptor plants. The volatiles inhibited root growth and promoted a brief increase in the number of RBCs. As the volatile concentration increased, the organelles in RBCs were gradually destroyed, and intracellular autophagosomes were produced and continuously increased in number. Transcriptomic analysis revealed that genes involved in the synthesis of the plasma membrane and cell wall components in receptor root cells were significantly up-regulated, particularly those related to cell wall polysaccharide synthesis. Meanwhile, polygalacturonase and pectin methylesterases (PME) exhibited up-regulated expression, and PME activity also increased. The contribution of α-terpene to this allelopathic effect of C. ambrosioides volatile oil exceeded 70%. Based on these results, receptor plant root tips may increase the synthesis of cell wall substances while degrading the intercellular layer, accelerating the generation and release of RBCs. Meanwhile, their cells survived through autophagy of RBCs, indicating the key role of RBCs in alleviating allelopathic stress from C. ambrosioides volatiles.
... (2) CcMan5C showed an optimal temperature of 70 °C for hydrolytic activity and retained over 80% of its activity after 1 h of incubation at 50 °C. Microbial mannanases have been shown to work at different temperatures, ranging from 37 °C to 70 °C [23][24][25]31,32,[47][48][49][50][51][52][53][54]. Several bacterial mannanases have displayed thermostable properties, rising up to 93 °C [23][24][25]. ...
... For example, a β-mannanase Man5XZ7 from thermophilic fungus Thielavia arenaria XZ7 was optimally active at pH5.0, but it only had 25.6% activity at pH8.0-9.0 [46]. (2) CcMan5C showed an optimal temperature of 70 • C for hydrolytic activity and retained over 80% of its activity after 1 h of incubation at 50 • C. Microbial mannanases have been shown to work at different temperatures, ranging from 37 • C to 70 • C [23][24][25]31,32,[47][48][49][50][51][52][53][54]. Several bacterial mannanases have displayed thermostable properties, rising up to 93 • C [23][24][25]. ...
A endo-1,4-β-mannanase (CcMan5C) gene was cloned from Coprinopsis cinerea and heterologously expressed in Pichia pastoris, and the recombinant enzyme was purified by Ni-affinity chromatography and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). CcMan5C hydrolyzed only locust bean gum galactomannan (LBG) but not α-mannan from S. cerevisiae or Avicel cellulose, oat spelt xylan, or laminarin from Laminaria digitata. CcMan5C exhibited distinctive catalytic features that were different from previously reported β-mannanases. (1) CcMan5C is the first reported fungal β-mannase with an optimal alkalic pH of 8.0–9.0 for hydrolytic activity under assay conditions. (2) CcMan5C is the first reported alkalic fungal β-mannase with an optimal temperature of 70 °C for hydrolytic activity under assay conditions. (3) The organic solvents methanol, ethanol, isopropanol, and acetone at concentrations of 10% or 20% did not inhibit CcMan5C activity, while 10% or 20% isopropanol and acetone even enhanced CcMan5C activity by 9.20–34.98%. Furthermore, CcMan5C tolerated detergents such as Tween 20 and Triton X-100, and its activity was even enhanced to 26.2–45.6% by 1% or 10% Tween 20 and Triton X-100. (4) CcMan5C solution or lyophilized CcMan5C exhibited unchanged activity and even increasing activity after being stored at −20 °C or −80 °C for 12 months and retained above 50% activity after being stored at 4 °C for 12 months. These features make CcMan5C a suitable candidate for the detergent industry and paper and pulp industry.
... Carbohydrate content was determined with the phenol-sulfuric acid method [42]. Specifically, 5-10 mg of freeze-dried biomass was suspended in 10-100 mL 3D H 2 O. ...
Nannochloropsis oculata is a marine microalgal species with a great potential as food or feed due to its high pigment, protein and eicosapentaenoic acid contents. However, for such an application to be realized on a large scale, a biorefinery approach is necessary due to the high cost of microalgal biomass production. For example, techno economic analyses have suggested the co-production of food or feed with antioxidants, which can be extracted and supplied separately to the market. The aim of this study was to investigate the effect of cultivation conditions on the antioxidant capacity of Nannochlosopsis oculata extracts, derived with ultrasound-assisted extraction at room temperature, as well as the proximate composition and fatty acid profile of the biomass. A fractional factorial approach was applied to examine the effects of temperature (20–35 °C), pH (6.5–9.5) and light period (24:0, 12:12). At the end of each run, biomass was collected, washed with 0.5M ammonium bicarbonate and freeze-dried. Antioxidant capacity as gallic acid equivalents as well as pigment content were measured in the ethanolic extracts. Optimal conditions were different for productivity and biomass composition. Interesting results regarding the effect of light period (LP) and pH require further investigation, whereas the effect of moisture on the extraction process was confounded with biomass composition. Finally, further data is provided regarding the relation between chlorophyll content and apparent phenolic content using the Folin–Ciocalteu assay, in agreement with our previous work.
... Degree of polymerization (DP) was calculated from the ratio of total sugar (TS) and reducing sugar (RS) (Eq 6). TS was determined using the method of Do et al. [25]. The sample (2.0 mL) was mixed with a phenol solution (5%, 1.0 mL) and concentrated H2SO4 (98%, 5.0 mL) under boiling in a water bath for 15 min. ...
Viscosity of glucomannan (GM) needs to be modified to support its application for spray drying encapsulation. The purpose of this study was to investigate degradation of GM using cellulase that fulfills viscosity in a spray-dryer specification. This hydrolyzed glucomannan (HGM) was subsequently spray-dried for encapsulating iron. Lower initial GM concentrations (0.5–1%) reached approximately 0.30 Pa·s which allowed to be spray-dried after 100 min degradation using 10 mg/L cellulase. Meanwhile, viscosity of 1.5% and 1.7% GM did not reach the target viscosity even after 300 min. The nth-order model was the most suitable model to achieve viscosity reduction of ≤1.5% initial GM concentration (coefficient of determination, R² > 0.98), whereas the Mahammad model fitted the viscosity reduction of 1.75% initial GM concentration (R² = 0.99). Hydrolysis decreased the degree of polymerization and surface tension but increased the antioxidant activities. Smaller molecules of the polysaccharides were released after hydrolysis. Particles of encapsulated iron using HGM were more hydrophilic than that using GM. The iron tended to have a higher release rate at pH 6.8 than at pH 1.2 in the first 40 min. Hence, the HGM showed its ability to act as a control release matrix for the iron that needs a protection in the acid environment, and delivers them to the neutral site for absorption. Nanoencapsulation using 0.35 Pa·s viscosity of HGM was able to have 84% yield, 96.41% encapsulation efficiency, and 10% moisture content. Particle size of the iron encapsulation was dominated by 68.62 nm-diameter. This study shows a potency to use an appropriate viscosity of HGM which not only allows to be spray-dried but also support in protecting the iron as aimed by encapsulation the iron. Performances and properties of this matrix on encapsulating other bioactive compounds become future study.
... Carbohydrate content was determined with the phenol-sulfuric acid method [27]. Specifically, 5-10 mg of freeze-dried biomass were suspended in 10-100 mL 3D H 2 O. ...
... While stirring with a magnet, 1 mL of the suspension was transferred to a glass vial and digested with 1 mL 5% phenol and 5 mL concentrated H 2 SO 4 . Absorption was measured at 490 nm and converted to glucose equivalents with a standard curve [27]. ...
There has been growing interest in microalgal biomolecules for health and cosmetics, as well as in the use of microalgae as aquaculture feed due to the need to replace fishmeal and fish oil with sustainable yet equally nutritious alternatives. Aim of this study is to evaluate the potential of five marine microalgal species, namely Chlorella minutissima, Dunaliella salina, Isochrysis galbana, Nannochloropsis oculata and Tisochrysis lutea, for the co-production of antioxidants and aquaculture feed. Batch cultivation was performed under saturating light intensity and continuous aeration. Freeze-dried biomass was extracted sequentially with water and methanol and evaluated for phenolic content and antioxidant activity, as well as proximate composition and fatty acid profile. Methanolic extracts of C. minutissima presented the highest phenolic content, measured with the Folin–Ciocalteu assay, and antioxidant activity. However, HPLC and LC-MS showed the presence of non-pigment compounds only in T. lutea. Total phenolic content and antioxidant activity were correlated to chlorophyll content. N. oculata and T. lutea were rich in eicosapentaenoic acid and docosahexaenoic acid, respectively, as well as in protein. In conclusion, N. oculata and T. lutea are suitable candidates for further optimization, while the data presented suggest that pigment effects on the Folin–Ciocalteu method require reconsideration.
... Historically, mannanases from the following origins have been characterized: In fungi such as Aspergillus awamori K4 [7], A. fumigatus IMI 385,708 [8], A. niger [9], Sclerotium rolfsii [10], and Trichoderma reesei [11]. In bacteria such as Bacillus subtilis [12,13], Streptomyces sp. ...
A novel endo-β-1,4-mannanase gene was cloned from a novel actinomycetes, Nonomuraea jabiensis ID06-379, isolated from soil, overexpressed as an extracellular protein (47.8 kDa) in Streptomyces lividans 1326. This new endo-1,4-β-mannanase gene (manNj6-379) is encoded by 445-amino acids. The ManNj6-379 consists of a 28-residue signal peptide and a carbohydrate-binding module of family 2 belonging to the glycoside hydrolase (GH) family 5, with 59–77% identity to GH5 mannan endo-1,4-β-mannanase. The recombinant ManNj6-379 displayed an optimal pH of 6.5 with pH stability ranging between 5.5 and 7.0 and was stable for 120 min at 50 °C and lower temperatures. The optimal temperature for activity was 70 °C. An enzymatic hydrolysis assay revealed that ManNj6-379 could hydrolyze commercial β-mannan and biomass containing mannan.
... The soluble sugar content was estimated by using Eq. 7 [32]: ...
This study was carried out to analyze the effects of biogenic silver nanoparticles (AgNPs) on physiological, biochemical, and enzymatic attributes of rice plants against Aspergillus flavus. The plant-based AgNPs were synthesized by using the aqueous extract of Moringa oleifera leaves. The characterization of AgNPs was accomplished through UV-visible spectrophotometry, SEM, and energy-dispersive X-ray (EDX) analysis, which confirmed that the nanoparti-cles are crystalline and are less than 100 nm in size. The exogenous applications of different concentrations of AgNPs (25, 50, 75, and 100 mg/L) on rice plants in field experiments were used to control the proliferation of A. flavus. The effects of biosynthesized AgNPs were evaluated for physiological (relative water content, membrane stability index, and chlorophyll content), nonenzymatic metabolites (total phenolic, total flavonoid, proline, soluble sugar, and protein contents), and enzymatic metabolites (superoxide dismutase, peroxidase, and catalase) in rice plants under biotic stress, and 50 mg/L concentration of AgNPs was found to be effective to elicit biochemical modifications to reduce biotic stress. The 50 mg/L concentration of AgNPs was also effective in controlling the proliferation of fungal pathogen. The applications of AgNPs reduced the biotic stress by decreasing the production level of osmolytes, enzymatic, and nonenzymatic compounds but significantly increased the protein content.
... The roots from the sampled seedlings were imaged under a scanner for determination of total length, volume, surface area, and mean diameter using WinRHIZO Pro (Regent Instruments, QC, Canada). The intracellular ultrastructure of the leaves was examined using TEM (H-7650; Hitachi) by sampling ~1-mm 2 pieces of the youngest fully expanded leaf as previously described by Dittmer et al. (2021). At least five independent biological replicates were examined for both roots and leaves. ...
... Free amino acids were extracted using potassium phosphate buffer, and the concentrations were determined spectrophotometrically at 750 nm after incubation with 2% ninhydrin and 10% pyridine (Hamilton and van Slyk, 1943). Betaine was extracted using 0.375% Reinecke salt (w/v) following as described previously (Do et al., 2009), and the absorbance was measured at 525 nm (Grieve and Grattan, 1983). ...
Vastness and complexity of the allotetraploid rapeseed genome is a huge challenge for understanding its salinity resistance. Herein, rapeseed plants of a salinity-resistant genotype (H159) and a salinity-sensitive genotype (L339) exhibited significantly differential salinity resistance. Integrated analysis of phenome, ionome, genome, and transcriptome was performed to identify the mechanisms underlying differential salinity resistance. Under salinity, a higher accumulation of osmoregulation substances and stronger root system architecture was observed in H159 than in L339. A lower shoot Na + concentration and a higher root vacuolar Na + concentration revealed a weaker root-to-shoot translocation and a stronger Na + compartmentation in H159 than in L339. Whole-genome re-sequencing (WGS) and transcriptome sequencing identified numerous DNA variants and differentially expressed genes involved in abiotic stress responses and ion transport. Combining ionomics with transcriptomics identified the plasma membrane-localized BnaC2.HKT1;1 and the tonoplast-localized BnaC5.NHX2 as the central members regulating differential root xylem unloading and vacuolar sequestration of Na + in rapeseed genotypes. WGS- and PCR-based sequence polymorphisms revealed two polymorphic MYB-binding sites in the promoter regions that might determine the differential gene expression of BnaC2.HKT1;1 and BnaC5.NHX2. The multi-omics approach used here eased the identification of core transporters involving Na + translocation and compartmentation regulating salinity resistance in rapeseed. Our data may provide elite gene resources for salinity resistance improvement in rapeseed and the multi-omics approach can be applied to other similar investigations.
... was obtained from the A. fumigatus. Based on multiple sequence alignment ( Figure 1A), AfMan5A shared the highest (74.4%) sequence identity with β-mannanase from Aspergillus niger BK01 [17], while sharing 49.9% with Man5A from Bispora sp. MEY-1 [18], 58.5% with TrMan5A from Trichoderma. ...
Aspergillus fumigatus HBFH5 is a thermophilic fungus which can efficiently degrade lignocellulose and which produces a variety of glycoside hydrolase. In the present study, a novel β-mannanase gene (AfMan5A) was expressed in Pichia pastoris and characterized. AfMan5A is composed of 373 amino acids residues, and has a calculated molecular weight of 40 kDa. It has been observed that the amino acid sequence of AfMan5A showed 74.4% homology with the ManBK from Aspergillus niger. In addition, the recombined AfMan5A exhibited optimal hydrolytic activity at 60 °C and pH 6.0. It had no activity loss after incubation for 1h at 60 °C, while 65% of the initial activity was observed after 1 h at 70 °C. Additionally, it maintained about 80% of its activity in the pH range from 3.0 to 9.0. When carob bean gum was used as the substrate, the Km and Vmax values of AfMan5A were 0.21 ± 0.05 mg·mL−1 and 15.22 ± 0.33 U mg−1·min−1, respectively. AfMan5A and AfSwol showed a strong synergistic interaction on galactomannan degradation, increasing the reduction of the sugars by up to 31%. Therefore, these findings contribute to new strategies for improving the hydrolysis of galactomannan using the enzyme cocktail.
