Xylose Content Research Articles

Physicochemical characterization and microbiota modulatory potential of brewer’s spent grain and arabinoxylan-derived fractions: A valorization study

Brewer’s spent grain (BSG), one of the largest by-products generated by brewing industries, holds a wealthy nutritional value due to its content in proteins and fibres. Although some initiatives have explored alternatives for leveraging the nutritional value of BSG, it mostly remains an underexploited source of valuable ingredients for human nutrition, being mainly dedicated to animal feed and landfilling. BSG is rich in hemicellulosic material, composed of arabinoxylans (AX), which have been postulated as emergent prebiotics, capable to confer health benefits through modulating the gut microbiome. In this work we comprehensively investigated in vitro the composition and gut microbiome modulatory potential of BSG and AX fractions on human microbiota of two population groups by means of fecal batch fermentations and 16S rRNA gene sequencing. The gut microbiome modulatory effects was influenced by the specific BSG/AX fraction; the population group (healthy or Crohn’s disease (CD) patients) and by interindividual variation. For instance, Dorea and Eubacterium halli which include well-known fibre degrading, and health promoting bacteria, were only stimulated in fermentations of fractions with high arabinose and xylose contents. This work demonstrates diverse modulatory capacity of distinct AX fractions, diversifying alternative BSG valorization strategies through exploitation of novel prebiotics tailored to specific groups.

The Fragile culm19 (FC19) mutation largely improves plant lodging resistance, biomass saccharification, and cadmium resistance by remodeling cell walls in rice

Cell wall is essential for plant upright growth, biomass saccharification, and stress resistance. Although cell wall modification is suggested as an effective means to increase biomass saccharification, it is a challenge to maintain normal plant growth with improved mechanical strength and stress resistance. Here, we reported two independent fragile culm mutants, fc19–1 and fc19–2, resulting from novel mutations of OsIRX10, produced by the CRISPR/Cas9 system. Compared to wild-type, the two mutants exhibited reduced contents of xylose, hemicellulose, and cellulose, and increased arabinose and lignin without significant alteration in levels of pectin and uronic acids. Despite brittleness, the mutants displayed increased breaking force, leading to improved lodging resistance. Furthermore, the altered cell wall and increased biomass porosity in fc19 largely increased biomass saccharification. Notably, the mutants showed enhanced cadmium (Cd) resistance with lower Cd accumulation in roots and shoots. The FC19 mutation impacts transcriptional levels of key genes contributing to Cd uptake, sequestration, and translocation. Moreover, transcriptome analysis revealed that the FC19 mutation resulted in alterations of genes mainly involved in carbohydrate and phenylpropanoid metabolism. Therefore, a hypothetic model was proposed to elucidate that the FC19 mutation-mediated cell wall remodeling leads to improvements in lodging resistance, biomass saccharification, and Cd resistance.

ZmXYL modulates auxin-induced maize growth.

Plant architecture, lodging resistance, and yield are closely associated with height. In this paper, we report the identification and characterization of two allelic EMS-induced mutants of Zea mays, xyl-1, and xyl-2, that display dwarf phenotypes. The mutated gene, ZmXYL, encodes an α-xylosidase which functions in releasing xylosyl residue from a β-1,4 linked glucan chain. Total α-xylosidase activity in the two alleles is significantly decreased compared to wild-type plants. Loss-of-function mutants of ZmXYL resulted in a decreased xylose content, an increased XXXG content in xyloglucan (XyG), and a reduced auxin content. We show that auxin has an antagonistic effect with XXXG in promoting cell divisions within mesocotyl tissue. xyl-1 and xyl-2 were less sensitive to IAA compared to B73. Based on our study, a model is proposed that places XXXG, an oligosaccharide derived from XyG and the substrate of ZmXYL, as having a negative impact on auxin homeostasis resulting in the dwarf phenotypes of the xyl mutants. Our results provide a novel insight into the roles of oligosaccharides released from plant cell walls as signals in mediating plant growth and development.

Effects of phytosanitary irradiation treatment and refrigerated storage on the physicochemical properties of three pectin types isolated from mandarin pulp

The impact of fruit exposure to ionizing energy as phytosanitary treatment on pectin properties has received little attention, especially on that from the flesh of citrus fruit other than oranges. In this study, hot-water, chelating agent and alkali soluble pectins (HWSP, CASP and ASSP) were extracted from juiced segments of mandarins that were treated with γ-irradiation (0, 0.15, 0.4 and 1 kGy) and stored (3 wks at 6 °C + 1 wk at 20 °C). Irradiation increased the recovery of HWSP and CASP and decreased the molecular weight (MW), the degree of methyl esterification (DME) and the protein content of the pectins. Storage further enhanced the recovery and the reduction of DME and MW of all tested pectins. The sum of the contents of arabinose, galactose, mannose and xylose was always lower in pectin from stored fruit as compared to pectin from non-stored fruit, independent of irradiation. Irradiation influenced the viscosity of the tested pectins from non-stored fruit. It did not impact the viscosity of pectins from stored fruit, which had a lower viscosity than that of pectins from non-stored fruit. Irradiation increased the hysteresis of pectins, independent of storage. Overall, irradiation and storage impacted the physicochemical properties of the pectins, negatively affecting their functionality.

Valorization of Avocado Seed Wastes for Antioxidant Phenolics and Carbohydrates Recovery Using Deep Eutectic Solvents (DES).

Avocado seeds represent the chief waste produced in avocado processing, leading not only to environmental problems regarding its elimination but to a loss of economic profitability. In fact, avocado seeds are known as interesting sources of bioactive compounds and carbohydrates, so their utilization may reduce the negative effect produced during the industrial manufacture of avocado-related products. In this sense, deep eutectic solvents (DES) are a novel greener alternative than organic solvents to extract bioactive polyphenols and carbohydrates. The study was based on a Box-Behnken experimental design to study the effect of three factors, temperature (40, 50, 60 °C), time (60, 120, 180 min) and water content (10, 30, 50% v/v) on the responses of total phenolic (TPC) and flavonoid content (TFC), antioxidant capacity (measured as ABTS and FRAP) and xylose content in the extract. The DES Choline chloride:glycerol (1:1) was used as solvent on avocado seed. Under optimal conditions, TPC: 19.71 mg GAE/g, TFC: 33.41 mg RE/g, ABTS: 20.91 mg TE/g, FRAP: 15.59 mg TE/g and xylose: 5.47 g/L were obtained. The tentative identification of eight phenolic compounds was assayed via HPLC-ESI. The carbohydrate content of the solid residue was also evaluated, and that solid was subjected to two different processing (delignification with DES and microwave-assisted autohydrolysis) to increase the glucan susceptibility to enzymes, and was also assayed reaching almost quantitative glucose yields. These results, added to the non-toxic, eco-friendly, and economic nature of DES, demonstrate that these solvents are an efficient alternative to organic solvents to recover phenolics and carbohydrates from food wastes.

Changes of bacterial community structure,monosaccharide composition and CO2 exchange along the successional stages ofbiological soil crusts.

Biological soil crusts (BSCs) are a dominantecological landscape of drylands, which have asignificant impact on global biogeochemical flux. However, it is unclear how bacterial community and physiological characteristics vary along the BSCssuccessional stages. In this study, bacterial community composition, physiological characteristics, and monosaccharide composition of extracellular polysaccharides (EPSs)were compared among different successional stages. Our findings demonstrated that besidesthe dominant bacterial species, the bacterial communities also showed considerable differences between these two stages. Cyanobacteria were keystone taxain the early stage, while heterotrophic bacteria (Proteobacteria, Actinobacteria and Acidobacteria) were keystone taxa in the later stages. According to the results ofCO2 exchange, cyanobacterial crusts accumulated net carbon faster than moss crusts, whilemoss crusts had a significantly higher respiration rate. The monosaccharide analysis indicated that the EPSs components also varied depending on BSCs' successional stages. Specifically, the contents of rhamnose and arabinose were higher in thecyanobacterial cruststhan other types of crusts, while the contents of fucose, xylose, mannose and glucose were the highest in cyanobacterial-lichen crusts, andgalactose contentwas highest inthe moss crusts. Altogether, our results stress the heterogeneous variation of BSCs along with succession, andthis work offered a fresh viewpoint for a deeper comprehension of the interactions between the monosaccharide components of EPS and the networks of bacterial communities in BSCs.

Chemical and histological characterization of internodes of sugarcane and energy-cane hybrids throughout plant development

Sugarcane and energy-cane are important Saccharum spp. hybrids that encompass desirable features for energy production. Their stem lignocellulose can be used as the raw material for the second-generation ethanol industry, contributing to accelerated fossil-fuel replacement. However, knowledge on the internode composition and saccharification of these hybrids is still needed to optimize their uses, especially in energy-cane. In this work, the agronomical, chemical, and histological internode features and saccharification potential were analyzed in sugarcane and energy-cane hybrids across four critical developmental stages (tillering, grand growth, early ripening and late ripening) and several internode positions along the stem. Except for galactose content that was higher in the sugarcane hybrid compared to the energy-cane, cell-wall composition was fairly similar in both types of cane across the growing cycle. Among main cell-wall components, maximum crystalline cellulose and matrix polysaccharides contents were observed at tillering and late ripening, respectively. Lignin concentrated towards upper internode positions and advanced developmental stages. Saccharification potential augmented towards apical internodes and early developmental stages, and negatively correlated to lignin and xylose contents. The energy-cane hybrid showed lower number of vascular bundles and metaxylem diameter and its lignin deposition was more extended towards the parenchymal tissue, when compared to the commercial sugarcane throughout the growth cycle. Taken together, these findings demonstrate that developmental stage and internode position largely affect cell-wall composition and its recalcitrance to enzymatic degradation. The use of sugarcane/energy-cane lignocellulose from early developmental stages could be beneficial for the second generation ethanol production. Novel management practices for that usage should consider economic, social and environmental sustainability standards under a sugar/ethanol production scheme.

Higher Aluminum Tolerance of Lespedeza bicolor Relative to Lespedeza cuneata Is Associated with Saccharide Components of Root Tips

Aluminum (Al) toxicity is the primary factor limiting agricultural productivity in acid soils. The cell wall is mainly composed of saccharides and the first barrier for aluminum (Al) to enter plant root cells, but it is unknown whether and how root saccharide components are involved in regulating the Al tolerance of Lespedeza that is well adapted to acid soils. Here, we used Al-tolerant Lespedeza bicolor and Al-sensitive Lespedeza cuneata to examine the association of root saccharide components with Lespedeza Al tolerance through analyzing the saccharide changes of roots exposed to Al toxicity. Al-sensitive Lespedeza accumulated more Al and pectin but less hemicellulose in the root cell walls than Al-tolerant Lespedeza. Al treatment decreased the amounts of total sugar secreted from and within the roots of only Al-tolerant Lespedeza. Al treatment decreased the content of root monosaccharides including glucose and mannose in both Lespedeza species, but increased the xylose contents in only Al-sensitive Lespedeza. Taken together, less cell wall pectin rather than hemicellulose is responsible for less root Al accumulation, and Al-decreased root saccharide contents may enhance root organic-acid secretion to chelate toxic Al, both of which contribute to Lespedeza Al tolerance.

Xylose Metabolization by a Saccharomyces cerevisiae Strain Isolated in Colombia

Saccharomyces cerevisiae (S. cerevisiae) is the most widely used yeast in biotechnology in the world because its well-known metabolism and physiology as well as its recognized ability to ferment sugars such as hexoses. However, it does not metabolize pentoses such as arabinose and xylose, which are present in lignocellulosic biomass. Lignocellulose is a widely available raw material, with xylose content of approximately 35% of total sugars. This xylose fraction could be used to obtain high added-value chemical products such as xylitol. One of these yeasts isolated from a Colombian locality, designated as 202-3, showed interesting properties. 202-3 was identified through different approaches as a strain of S. cerevisiae, with an interesting consumption of xylose metabolizing into xylitol, in addition with excellent ability as a hexose fermenter with high ethanol yields and shows resistance to inhibitors present in lignocellulosic hydrolysates. The xylose metabolization by the 202-3 strain and their kinetics parameters had not been previously reported for any other natural strain of S. cerevisiae. These results suggest the great potential of natural strains for obtaining high value-added chemical products using sugars available in lignocellulosic biomass.

Morpho-biochemical characterization of a RIL population for seed parameters and identification of candidate genes regulating seed size trait in lentil (Lens culinaris Medik.).

The seed size and shape in lentil (Lens culinaris Medik.) are important quality traits as these influences the milled grain yield, cooking time, and market class of the grains. Linkage analysis was done for seed size in a RIL (F5:6) population derived by crossing L830 (20.9 g/1000 seeds) with L4602 (42.13 g/1000 seeds) which consisted of 188 lines (15.0 to 40.5 g/1000 seeds). Parental polymorphism survey using 394 SSRs identified 31 polymorphic primers, which were used for the bulked segregant analysis (BSA). Marker PBALC449 differentiated the parents and small seed size bulk only, whereas large seeded bulk or the individual plants constituting the large-seeded bulk could not be differentiated. Single plant analysis identified only six recombinant and 13 heterozygotes, of 93 small-seeded RILs (<24.0 g/1000 seed). This clearly showed that the small seed size trait is very strongly regulated by the locus near PBLAC449; whereas, large seed size trait seems governed by more than one locus. The PCR amplified products from the PBLAC449 marker (149bp from L4602 and 131bp from L830) were cloned, sequenced and BLAST searched using the lentil reference genome and was found amplified from chromosome 03. Afterward, the nearby region on chromosome 3 was searched, and a few candidate genes like ubiquitin carboxyl-terminal hydrolase, E3 ubiquitin ligase, TIFY-like protein, and hexosyltransferase having a role in seed size determination were identified. Validation study in another RIL mapping population which is differing for seed size, showed a number of SNPs and InDels among these genes when studied using whole genome resequencing (WGRS) approach. Biochemical parameters like cellulose, lignin, and xylose content showed no significant differences between parents and the extreme RILs, at maturity. Various seed morphological traits like area, length, width, compactness, volume, perimeter, etc., when measured using VideometerLab 4.0 showed significant differences for the parents and RILs. The results have ultimately helped in better understanding the region regulating the seed size trait in genomically less explored crops like lentils.

Development of novel ternary deep eutectic pretreatment solvents from lignin-derived phenol, and its efficiency in delignification and enzymatic hydrolysis of peanut shells

This work evaluated the effectiveness of a novel deep eutectic solvents (DES) prepared from guaiacol (GG), and p-hydroxybenzoic acid (PB) as a double hydrogen bond donor and choline chloride (ChCl) as a hydrogen bond receptor. The effect of ChCl-GG-PB on the structural properties and enzymatic hydrolysis of peanut shell was analyzed. Furthermore, the performance of ChCl-GG-PB as a hydrogen bond donor was compared with two other DES of PB and GG as hydrogen bond donors, and the effects of molar ratio, temperature and time were studied. The results showed that after ChCl-GG-PB pretreatment, hemicellulose and lignin were effectively removed, the removal rate was about 63.36% and 69.54%, respectively, and the enzymatic glycosaccharification efficiency was significantly improved, of which the xylose content was 5.5 times higher than the untreated. In addition, ChCl-GG-PB pretreated showed significant changes in the structure and morphology, with the highest crystallinity and lowest solid recovery. These results affirms that the proposed novel ternary DES is a promising pretreatment solvent that can effectively deconstruct lignocellulose and improve cellulose digestibility, thereby achieving an economically viable biomass conversion method.

Genetic dissection of monosaccharides contents in rice whole grain using genome-wide association study.

The simplest form of carbohydrates are monosaccharides which are the building blocks for the synthesis of polymers or complex carbohydrates. Monosaccharide contents of 197 rice accessions were quantified by HPAEC-PAD in rice (Oryza sativa L.) whole grain (RWG). A genome-wide association study (GWAS) was carried out using 33,812 single nucleotide polymorphisms (SNPs) to identify corresponding genomic regions influencing neutral monosaccharides contents. In total, 49 GWAS signals contained in 17 genomic regions (quantitative trait loci [QTLs]) on seven chromosomes of rice were determined to be associated with monosaccharides contents of whole grain. The QTLs were found for fucose (1), mannose (1), xylose (2), arabinose (2), galactose (4), and rhamnose (7) contents, all of which are novel. Based on co-location of annotated rice genes in the vicinity of GWAS signals, the constituents of the whole grain were associated with the following candidate genes: arabinose content with α-N-arabinofuranosidase, pectinesterase inhibitor, and glucosamine-fructose-6-phosphate aminotransferase 1; xylose content with ZOS1-10 (a C2H2 zinc finger transcription factor [TF]); mannose content with aldose 1-epimerase-like protein and a MYB family TF; galactose content with a GT8 family member (galacturonosyltransferase-like 3), a GRAS family TF, and a GH16 family member (xyloglucan endotransglucosylase/hydrolase xyloglucan 23); fucose content with gibberellin 20 oxidase and a lysine-rich arabinogalactan protein 19, and finally rhamnose content with myo-inositol-1-phosphate synthase, UDP-arabinopyranose mutase, and COBRA-like protein precursor. The results of this study should improve our understanding of the genetic basis of the factors that might be involved in the biosynthesis, regulation, and turnover of monosaccharides in RWG, aiming to enhance the nutritional value of rice grain and impact the relatedindustries.

Microbial lipid production from soybean hulls using Lipomyces starkeyi LPB53 in a circular economy

Soybean hulls are lignocellulosic residuesgeneratedinthe industrial processing of soybean, representing about 5 % of the mass of the whole bean. This by-product isan importantsource of polymers suchas cellulose(34 %) and hemicellulose (11 %),which could bevalorizedvia biotechnology to improvethe economic returnof the oilseed chain. In the present work,soybean hulls were evaluated as a carbon sourcefor biolipid productionbyLipomycesstarkeyi LPB 53. Initially the hulls were treated physicochemically and enzymatically to obtain fermentable sugars. Subsequently, biomass growth was evaluated using different nitrogen sources andthe lipid production was optimized, reaching a maximum cell biomass concentration of 26.5 g/L with 42.5 % of lipids. Around 65 % of the xylose content was consumed.The obtained oil wasmajorlycomposed of oleic, palmitic, palmitoleic, linoleic and stearic fatty acids in a proportion of 54 %, 32 %, 4 %, 3 % and 2 %, respectively.

Metabolomic and Transcriptomic Changes Underlying the Effects of L-Citrulline Supplementation on Ram Semen Quality.

This study examined the effects of L-Cit supplementation on ram semen quality through metabolomics and transcriptomics. A total of 16 rams were randomly categorized into two groups. The control group was fed a basic diet, whereas the experimental group received feed supplemented with 12 g/d of L-Cit. Semen and blood were collected from the rams on days 0 and 72 to measure sugar, pyruvate, amino acid, and nontargeted metabolite contents. Additionally, hypothalamic and testicular tissues were collected for a transcriptomic analysis. We found 27 differential metabolites between the control and experimental groups, of which 21 were downregulated (p &lt; 0.05) and 6 were upregulated (p &lt; 0.05). Compared with the control group, xylose and pyruvate contents in seminal plasma increased by 43.86% and 162.71%, respectively (p &lt; 0.01). Additionally, the levels of 11 amino acids showed a significant increase in seminal plasma (p &lt; 0.01). Furthermore, 961 and 715 differentially expressed genes were detected in the hypothalamic and testicular tissues, respectively. The pathways of significant enrichment in the hypothalamus and testes were protein digestion, absorption, glycolysis/gluconeogenesis, and amino as well as nucleotide sugar metabolisms. In the present study, L-Cit improved protein synthesis and blood metabolism, consequently increasing the contents of most amino acids in ram seminal plasma. Specifically, the hypothalamus controlled the expression of glycolysis/gluconeogenesis-related genes in the testes through its metabolites released into the serum, thereby providing energy for sperm production, which led to a decrease in the sugar content of seminal plasma.

Crabtree Effect on Rhodosporidium toruloides Using Wood Hydrolysate as a Culture Media

The interest in microorganisms to produce microbial lipids at large-scale processes has increased during the last decades. Rhodosporidium toruloides-1588 could be an efficient option for its ability to simultaneously utilize five- and six-carbon sugars. Nevertheless, one of the most important characteristics that any strain needs to be considered or used at an industrial scale is its capacity to grow in substrates with high sugar concentrations. In this study, the effect of high sugar concentrations and the effect of ammonium sulfate were tested on R. toruloides-1588 and its capacity to grow and accumulate lipids using undetoxified wood hydrolysates. Batch fermentations showed a catabolic repression effect on R. toruloides-1588 growth at sugar concentrations of 120 g/L. The maximum lipid accumulation was 8.2 g/L with palmitic, stearic, oleic, linoleic, and lignoceric acids as predominant fatty acids in the produced lipids. Furthermore, R. toruloides-1588 was able to utilize up to 80% of the total xylose content. Additionally, this study is the first to report the effect of using high xylose concentrations on the growth, sugar utilization, and lipid accumulation by R. toruloides-1588.

Effect of lactobacilli inoculation on protein and carbohydrate fractions, ensiling characteristics and bacterial community of alfalfa silage.

Alfalfa (Medicago sativa L.) silage is one of the major forages with high protein for ruminants. The objective of this study was to investigate the effects of lactobacilli inoculants on protein and carbohydrate fractions, ensiling characteristics and bacterial community of alfalfa silage. Wilted alfalfa (35% dry matter) was inoculated without (control) or with Lactobacillus coryniformis, Lactobacillus casei, Lactobacillus plantarum, and Lactobacillus pentosus and ensiled for 7, 15, and 60 days. Silage inoculated with L. pentosus was superior to L. coryniformis, L. casei, L. plantarum in improving the fermentation quality of alfalfa silage, as indicated by the lowest ammonia nitrogen content and silage pH during ensiling. There was minor difference in water soluble carbohydrates content among all silages, but L. pentosus inoculants was more efficient at using xylose to produce lactic acid, with lower xylose content and higher lactic acid content than the other inoculants. Compared with the control, L. pentosus inoculants did not affect true protein content of silage, but increased the proportions of buffer soluble protein and acid detergent soluble protein. The L. pentosus inoculants reduced the bacterial diversity In alfalfa silage with lower Shannon, Chao1, and Ace indices, and promoted relative abundance of lactobacillus and decreased the relative abundance of Pediococcus compared with the control. As well as L. pentosus inoculants up-regulated amino acid, carbohydrate, energy, terpenoids, and polypeptides metabolism, and promoted lactic acid fermentation process. In summary, the fermentation quality and nutrient preservation of alfalfa silage were efficiently improved by inoculated with L. pentosus.

Monosaccharide Composition and In Vitro Activity to HCT-116 Cells of Purslane Polysaccharides after a Covalent Chemical Selenylation.

The anti-cancer effects of selenylated plant polysaccharides are a focus of research. As a natural plant with extensive biological effects, there have been few studies related to edible purslane (Portulaca oleracea L.). Thus, in this study, soluble P. oleracea polysaccharides (PPS) were extracted from the dried P. oleracea and then selenylated chemically using the HNO3-Na2SeO3 method to obtain two selenylated products, namely, SePPS1 and SePPS2. Compared with the extracted PPS, SePPS1 and SePPS2 had much higher Se contents (840.3 and 1770.5 versus 66.0 mg/kg) while also showing lower contents in three saccharides-arabinose, fucose, and ribose-and higher contents in seven saccharides including galactose, glucose, fructose, mannose, rhamnose, galacturonic acid, and glucuronic acid, but a stable xylose content demonstrated that the performed chemical selenylation of PPS led to changes in monosaccharide composition. Moreover, SePPS1 and SePPS2 shared similar features with respect to monosaccharide composition and possessed higher bioactivity than PPS in human colon cancer HCT-116 cells. Generally, SePPS1 and SePPS2 were more active than PPS with respect to cell growth inhibition, the alteration of cell morphology, disruption of mitochondrial membrane potential, intracellular reactive oxygen species (ROS) generation, the induction of cell apoptosis, and upregulation or downregulation of five apoptosis-related genes and proteins such as Bax, Bcl-2, caspases-3/-9, and cytochrome C, that cause cell apoptosis and growth suppression via the ROS-mediated mitochondrial pathway. SePPS2 consistently showed the highest capacity to exert these observed effects on the targeted cells, suggesting that the performed chemical selenylation of PPS (in particular when higher degrees of selenylation are reached) resulted in an increase in activity in the cells. It can thus be concluded that the performed selenylation of PPS was able to incorporate inorganic Se into the final PPS products, changing their monosaccharide composition and endowing them with enhanced nutraceutical and anti-cancer effects in the colon.

Structural and nutritional properties of psyllium husk arabinoxylans with special reference to their antioxidant potential

ABSTRACT The current research aimed to extract and characterize arabinoxylans (AX) from psyllium seeds husk for their nutritional and structural properties. For this purpose, psyllium husk (PH) was procured from the local market and subjected for the nutritional profile, dietary fiber (DF) composition, and AXs extraction. The extraction of AXs from psyllium seed husk was done through enzymatic method and Fourier transform infrared (FTIR) spectroscopy was used for its structural characterization. Further, the antioxidant activity of AXs was also elucidated using ferric reducing antioxidant power (FRAP) and diphenyl picryl hydrazyl (DPPH) assays. Results showed that psyllium seed husk is a good source of DFs (61.5 ± 2.6%) and the proximate composition including moisture, ash, crude fat, crude protein, crude fibers, and Nitrogen free extract (NFE) was 4.9 ± 0.01, 4.1 ± 0.01, 1.2 ± 0.01, 3.9 ± 0.05, 20.23 ± 0.4 and 78.2 ± 4.01 g/100 g, respectively. Furthermore, AXs content was 68.29 ± 3.4 g/100 g of PH. Different monosaccharides including xylose, arabinose, rhamnose, glucose, and galactose contents in PHAXs were 64.23 ± 1.04%, 13.38 ± 0.16%, 1.43 ± 0.04%, 1.89 ± 0.05%, and 3.64 ± 0.07%, respectively. FTIR absorption peaks from 900 to 1100 cm−1 showed spectra of AXs with the highest peak from 980 to 1015 cm−1 reflecting arabinose and xylose ratio. Additionally, the substitution positions on the xylan backbone were 2800–3400 cm−1 of O-H stretching vibrations and peaks of C-H stretching at 2853 and 2923 cm−1. The antioxidant activity of PHAXs exhibited that the FRAP value of extracted AXs was 1.39 ± 0.06 μmol Fe2+/g and the DPPH value was 3.01 ± 0.15 Trolox mg/g. It is depicted that PH is a good source of AXs (non-starch polysaccharide) with better antioxidant potential.

Impact of structure and composition of different sorghum xylans as substrates on production of xylanase enzyme by Aspergillus fumigatus RSP-8

Xylan composition from six different bmr sorghum (Sorghum bicolor L.) biomasses (Atlas 12, BN 612, Atlas 3986, IS 27333, Atlas N598 & IS 27206) with variable lignin content were analyzed for their structure and evaluated as a substrate for xylanase complex production using Aspergillus fumigatus RSP-8. Chemical compositional analysis of xylans revealed that all the xylans belong to arabinoxylan (AX) type and are composed of xylose, glucose, and arabinose in varying concentrations. The relative content of xylose varied from 90 % (of total sugars) in the variety IS 27206 to 72 % in Atlas N598. Atlas N598 xylan contained the highest relative glucose content of 22 % and the least content was observed in IS 27206 xylan (2.9 %). The relative content of L-arabinose was constant with fewer variations (5.1–6.7 %). FT-IR analysis showed that the xylans extracted from different sorghum substrates varied in structure. The spectra of all the xylans exhibited absorption maxima of ∼895 cm-1 which is characteristic for the β-(1−4) xylans. The strongest absorption bands in the IR spectra were observed at 3700–3000 and 1200–1000 cm-1 with varying intensities. Xylanase production revealed that the source of xylan significantly affected the fungal growth and xylanase productivity. The highest xylanase production (1248 U/mL) and fungal biomass dry weight (5.94 g/L) was observed with IS 27206 xylan and the least productivity of 964 U/mL and fungal biomass dry weight (3.74 g/L) with Atlas N598 xylan noticed as substrate.

Biochemical and Structural Characterization of Ferulated Arabinoxylans Extracted from Nixtamalized and Non-Nixtamalized Maize Bran.

Maize bran is a good source of non-starch polysaccharides, having various bioactive compounds. In the current research, we extracted the ferulated arabinoxylans from nixtamalized maize bran (NMB) and non-nixtamalized maize bran (NNMB) and explored their biochemical composition (monosaccharides, phenolic compounds) and structural characteristics (FTIR, SEM and XRD) as well as antioxidant activity. Results showed that contents of ferulated arabinoxylans were 8.1 ± 0.04% and 6.8 ± 0.02 in NMB and NNMB, respectively. Moreover, the purity of arabinoxylans was 60.1 ± 0.8% and 57.04 ± 0.7% in NMB and NNMB ferulated arabinoxylans. Furthermore, ferulated arabinoxylans have higher arabinose, xylose and ferulic acid contents. FTIR spectra of NMB and NNMB ferulated arabinoxylans depicted the presence of polysaccharide compounds and the corresponding band was observed at 993 cm-1, which is due to glycosidic bond vibration. In addition, absorbance regions of arabinoxylans between 900 cm-1 to 1200 cm-1 were observed. Moreover, SEM micrographs of ferulated arabinoxylans had visible rough and porous surface morphology. Further, ferulated arabinoxylans of NMB and NNMB did not exhibit any sharp peaks in XRD graphs, attributed to their amorphous nature. However, XRD 2θ showed peaks at 20.0°, which predominantly indicated that the material has an amorphous state with small crystalline regions in the sample, which shows the presence of xylans (small and narrow sharp peaks).