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The biocatalytic approach based on Levansucrase (LS)-catalyzed transfructosylation reaction is of particular interest for the synthesis of well-defined FOSs and β-(2−6)-levan. The present study aims to characterize the catalytic properties, kinetics, and end-product profiles of new LSs derived from Novosphingobium aromaticivoran s, Vibrio natriegens, Gluconobacter oxydans, and Burkholderia graminis. The optimal conditions for achieving the highest ratio of transfructosylation to hydrolysis was achieved were identified as follows: N. aromaticivorans LS1 (T 45 °C, pH 6, E a 33.88 kJ/mol), V. natriegens LS2 (T= 45 °C, pH 5, E a = 12.74 kJ/mol), B. graminis LS3 (T= 35 °C, pH 7, E a = 20.72 kJ/mol), and G. oxydans LS4 (T= 30 °C, pH 5, E a = 51.85 kJ/mol). The kinetic study revealed that LS from G. oxydans LS4 had the highest catalytic efficiency for the transfructosylation of sucrose (112.96 s−1M−1) and raffinose (1142.7 s−1 M−1) than their hydrolysis (39.15 and 16.5 s−1M−1 respectively). Our results highlighted the end-product profile of each LS using sucrose and raffinose as donor substrates. V. natriegens LS2 and B. graminis LS3-catalyzed sucrose bioconversion reaction resulted in the synthesis of more diverse FOSs. When compared to FOSs, all LSs catalyzing sucrose and raffinose bioconversion produced high yields of oligolevans/levans. [Display omitted] • Catalytic properties and optimum conditions for achieving the highest transfructosylation to hydrolysis ratio were identified for 4 novel levansucrases (LSs). • LS from G. oxydans exhibited the highest catalytic efficiency for the transfructosylation of sucrose and raffinose. • All LSs exhibited higher catalytic efficiency towards transfructosylation of raffinose than its hydrolysis. • V. natriegens and B. graminis LSs catalyzing sucrose transfructosylation led to diverse fructooligosaccharides (FOSs). • All LSs catalyzing sucrose and raffinose bioconversion led to high yields of oligolevans/levans than FOSs. [ABSTRACT FROM AUTHOR]

Fructans are important polysaccharides synthesized from sucrose which are present in about 12–15% of angiosperms. Sunflower (Helianthus annuus L.) is considered a non-fructan bearing plant even though its close relative, Helianthus tuberosus , accumulates the inulin type of the polymer in large amounts. Previous work suggested that putative fructan-synthesizing enzymes may be expressed in sunflower, but only very limited amounts of the trisaccharide isokestose were found in stems of plants storing high levels of sucrose due to capitulum removal. The present work is aimed at investigating whether intact sunflower plants may indeed synthesize fructans in any of its parts when grown in conditions that favor sucrose availability. Plants were grown in the field at a low density, resulting in a high light availability and low competition for resources, in comparison with controls (usual crop planting density). Plants were harvested at anthesis. Thinned treatment led to an increase in carbohydrates level especially in the capitulum. Carbohydrates analysis of this tissue in thinned plants revealed, for the first time in this species, the presence of inulin-type fructans. The amount of each member of the series appeared to decline starting from isokestose, being DP = 15 the longest fructan detected. Results suggest that, in sunflower, fructans could be synthesized only when sucrose availability exceeds a high threshold, which may not be attained under usual growing conditions. Given the relationship between fructans and tolerance to abiotic stresses including drought, the present finding opens a new perspective for breeding and management of this crop. • Sunflower capitulum was the main site of carbohydrate accumulation at anthesis. • Inulin-type fructan were found in sunflower capitulum under high irradiance conditions. • A certain amount of carbohydrates should be attained to trigger the induction of fructan synthesis. • Fructan synthesis in sunflower opens a new perspective for breeding and management of this crop. [ABSTRACT FROM AUTHOR]

The urgent task of creating new, enhanced adjuvants is closely related to our comprehension of their mechanisms of action. A few adjuvants have shown sufficient efficacy and low toxicity to be allowed for use in human vaccines, despite the fact that they have a long history and an important function. Adjuvants have long been used without a clear understanding of how precisely they augment the immune response. The rational production of stronger and safer adjuvants has been impeded by this lack of information, which necessitates more mechanistic research to support the development of vaccines. Carbohydrate structures–polygalactans, fructans, β-D-glucans, α-D-glucans, D-galactose, and D-glucose–are desirable candidates for the creation of vaccine adjuvants and immunomodulators because they serve important functions in nature and are often biocompatible, safe, and well tolerated. In this review, we have discussed recent advances in microbial-derived carbohydrate-based adjuvants, their immunostimulatory activity, and the implications of this for vaccine development, along with the critical view on the microbial sources, chemical composition, and biosynthetic pathways. • Selecting an appropriate adjuvant is deemed to be a significant challenge in vaccinology. • Toxicity and adverse effects of known adjuvants impede their human use. • Carbohydrates (β-glucan) can effectively involve the immune system. • Carbohydrate-based adjuvants function as a promising vaccine adjuvant candidate. [ABSTRACT FROM AUTHOR]

The physicochemical properties of the polysaccharides in Polygonatum kingianum , a Chinese medicinal herb used for both medicine and food, have not been fully studied. This study isolated three polysaccharides (PKP-1, PKP-2, and PKP-3) from the dry rhizomes of P. kingianum , with an average molecular weight of approximately 3137 Da, 5341 Da and 3755 Da, respectively. Structural analysis showed that all the three polysaccharides are fructans with β-D-Fru f -(2→, →6)-β-D-Fru f -(2→, →1)-β-D-Fru f -(2→, →1,6)-β-D-Fru f -(2→ and →6)-α-D-Glc p -(1→ glycosidic bond type. Notably, PKP-2 contains both acetyl groups and trace amounts of mannose residues. Scanning electron microscopy indicated that each polysaccharide possesses unique surface morphology. Thermal analysis showed that the three polysaccharides have good thermal stability. Rheological studies further revealed that all the three polysaccharides are typical shear thinning fluids. In vitro experiments showed that PKP-1 and PKP-2 significantly promote the secretion of NO and cytokines (TNF-α, IL-6) in macrophages by activating the NF-κB signaling pathway, thereby demonstrating potential immunomodulatory activity. These findings lay a theoretical foundation for the potential application of Polygonatum polysaccharides in the food industry. • Isolation of three polysaccharides from Polygonatum kingianum. • Three polysaccharides belong to fructans similar to Graminans series. • Three polysaccharides with good thermal stability and typical shear-thinning fluid properties. • Polysaccharides PKP-1 and PKP-2 have immunomodulatory effects on RAW264.7 cells in vitro. [ABSTRACT FROM AUTHOR]

Glycoside hydrolase family 91 (GH91) inulin fructotransferase (IFTases) enables biotransformation of fructans into sugar substitutes for dietary intervention in metabolic syndrome. However, the catalytic mechanism underlying the sequential biodegradation of inulin remains unelusive during the biotranformation of fructans. Herein we present the crystal structures of IFTase from Arthrobacter aurescens SK 8.001 in apo form and in complexes with kestose, nystose, or fructosyl nystose, respectively. Two kinds of conserved noncatalytic binding regions are first identified for IFTase-inulin interactions. The conserved interactions of substrates were revealed in the catalytic center that only contained a catalytic residue E205. A switching scaffold was comprised of D194 and Q217 in the catalytic channel, which served as the catalytic transition stabilizer through side chain displacement in the cycling of substrate sliding in/out the catalytic pocket. Such features in GH91 contribute to the catalytic model for consecutive cutting of substrate chain as well as product release in IFTase, and thus might be extended to other exo -active enzymes with an enclosed bottom of catalytic pocket. The study expands the current general catalytic principle in enzyme-substrate complexes and shed light on the rational design of IFTase for fructan biotransformation. [ABSTRACT FROM AUTHOR]

Allium plants, including garlic, onions, shallots, and leeks, belong to the Alliaceae family and are utilized as vegetable, medicinal, and ornamental plants. These plants are consumed both raw and cooked and are noted in traditional medicine for their antibacterial, antitumor, and diuretic properties. Allium plants are a rich source of polyphenols, organosulfur compounds, flavonoids, alkaloids, and polysaccharides, which contribute to their health benefits. As consumer interest in the association between diet and health grows, there is an increasing market demand for foods that promote health, particularly those rich in dietary fiber or non-starch polysaccharides. Allium polysaccharides (APS) have molecular weights of 1 × 103–1 × 106 Da containing small amounts of pectin, glucofructan, or glycoproteins and large amounts of fructans. APS, despite its complex structure, is one of the principal active components of Allium plants but is often overlooked, which restricts its practical application. This paper provides a comprehensive overview of the extraction and purification, structural and functional characteristics, bioactivities, structure-function relationships, and chemical modifications of APS, as well as the effects of APS processing and storage. Additionally, this paper outlines future research directions for APS, which will inform its development and application in the food, pharmaceutical, and cosmetic industries. [Display omitted] • Extraction and purification methods of Allium polysaccharides (APS) were summarized. • Structural characteristics and chemical modifications of APS were introduced. • Diversified biological activities and underlying mechanisms of APS were elaborated. • Structure-function relationships of APS were comprehensively analyzed. [ABSTRACT FROM AUTHOR]

• Starch concentration in gastric digesta decreased up to 44 %. • Sucrose was completely cleared from gastric digesta on pasture and with hay. • Fructans disappeared from gastric digesta on pasture and with hay. • Higher evidence for gastric degradation of fibre was in horses on pasture. Concentrations of starch, mono- and disaccharides, fructans, hemicellulose and cellulose were analysed in feed and gastric digesta of horses in relation to acid insoluble ash as a marker indigestible in the stomach. Twenty-four horses were allocated to pasture 24 h/d (PST; n = 4), hay ad libitum (HAY; n = 8), hay ad lib. and oats at 1 g starch/kg body weight (BWT)/meal (OS1; n = 6) and hay ad lib. and oats at 2 g starch/kg BWT/meal (OS2; n = 5). One horse was excluded from the analysis. The horses were fed the ration a minimum of 34 days. Following euthanasia and dissection, digesta was sampled from Pars nonglandularis (PNG) and Pars glandularis (PG). Oat starch concentration in gastric digesta decreased from 309 to 174 g/kg dry matter (DM) in OS1 (44 %-reduction) and from 367 to 261 g/kg DM in OS2 (29 %-reduction) (P < 0.001). Glucose, fructose and sucrose disappeared from gastric digesta distinctly more in PST, HAY and OS1 than in OS2. In PST and HAY, sucrose concentration was completely cleared (P < 0.001). The concentration of fructans was reduced predominantly in PST (84 %-reduction) and HAY (54 %-reduction), mainly in the PNG (P < 0.05). Fructan degradation did not occur in the high-starch diet (OS2). Some evidence for fibre degradation was observed in PST (P < 0.01). Soluble carbohydrates disappear from the stomach dependent on the type of ration, which may lead to changes in the composition of the gastric microbial community and the endogenous response. [ABSTRACT FROM AUTHOR]

• Fructansucrase from Lactiplantibacillus plantarum was characterized as inulosucrase. • The enzyme exhibited low pH optima and dependence on metal ions such as Ca2+. • 1H NMR analysis revealed the enzyme product to be inulin. • Methylation analyses revealed > 80 % β -2,1-linked, and 7 % β -2,1,6-linked Fru f units. • The molecular weight of inulin was relatively lower as assessed by HP- SEC analysis. Fructansucrases produce fructans by polymerizing the fructose moiety released from sucrose. Here, we describe the recombinant expression and characterization of a unique fructansucrase from Lactiplantibacillus plantarum DKL3 that showed low sequence similarity with previously characterized fructansucrases. The optimum pH and temperature of fructansucrase were found to be 4.0 and 35 °C, respectively. Enzyme activity increased in presence of Ca2+ and distinctly in presence of Mn2+. The enzyme was characterized as an inulosucrase (LpInu), based on the production of an inulin-type fructan as assessed by NMR spectroscopy and methylation analysis. In addition to β -2,1-linkages, the inulin contained a few β -2,1,6-linked branchpoints. High-performance size exclusion chromatography with refractive index detection (HPSEC-RI) revealed the production of inulin with a lower molecular weight compared to other characterized bacterial inulin. LpInu and its inulin product represent novel candidates to be explored for possible food and biomedical applications. [ABSTRACT FROM AUTHOR]

Codonopsis polysaccharides (CPs) are the main bioactive ingredients of Codonopsis Radix (CR), the dried roots of Codonopsis pilosula (Franch.) Nannf., which are widely used as an edible traditional Chinese medicine. Increasing evidence indicates that CPs are rich in inulin-type fructans. However, the molecular mechanism of inulin-type fructan synthesis remains unclear in C. pilosula. This study aimed to characterize the function of the Cp1-SST gene in fructan biosynthesis in C. pilosula roots. The results showed that Cp1-SST , a gene encoding sucrose:sucrose 1-fructosyltransferase (1-SST), was highly expressed in the roots and exhibited a similar trend of change in fructan accumulation under drought and cold stress. Subcellular location analysis demonstrated that Cp1-SST was located within the chloroplast. Silencing of the Cp1-SST gene reduced the content of CPs, fructans, and other bioactive ingredients, such as lobetyolin and codonopyrrolidium B, whereas it increased the expression levels of NI , FEH , and the SuSy gene related to fructan accumulation. Surprisingly, overexpression of Cp1-SST in tobacco resulted in the synthesis of fructooligosaccharides with different degrees of polymerization, including 1-kestose, nystose, fructoheptasaccharide, fructo-oligosaccharide DP8, and fructo-oligosaccharide DP9. At the same time, consumption of sucrose, the substrate of the Cp1-SST enzyme, led to nutrient deficiency in the transgenic seedlings and eventually inhibited their growth. Nonetheless, Cp1-SST overexpression significantly enhanced the resistance of the transgenic tobacco to cold stress. Collectively, these findings demonstrate that Cp1-SST is a novel gene that is significant in fructan accumulation and CR quality, and therefore has high agricultural and economic value. • Cp1-SST was located in chloroplast and highly expressed in the roots. • Cp1-SST affected the production of fructooligosaccharides and fructan in C. pilosula. • Reduction of codonopyrrolidium B and lobetyolin was induced by Cp1-SST silencing. • Overexpression of Cp1-SST enhanced the plant resistance to cold stress. [ABSTRACT FROM AUTHOR]

Non-starch polysaccharides exhibit numerous beneficial health effects but compounds belonging to FODMAP (Fermentable Oligo- Di- and Monosaccharides and Polyols) has been recently connected to several gastrointestinal disorders. This review presents integrated literature data on the occurrence and types of fructans and fructooligosaccharids (classified as FODMAPs) as well as their degrading enzymes present in plants. Plants from the family Asteraceae and many monocotyledones, including families Poaceae and Liliaceae, are the most abundant sources of both fructans and fructan-degrading enzymes. So far, vast majority of publications concerning the application of these specific plants in production of bakery products is related to increase of dietary fibre content in these products. However, there is limited research on their effect on FODMAP content and fibre balance. The authors emphasize the possibility of application of enzyme rich plant extract in food production casting light on the new scientific approach to fibre modification. [Display omitted] • Fructans are widely distributed in the plant kingdom as valuable energy source. • Fructans are classified into three main types: inulin, levan and branched group. • Fructan rich plants are valuable source of fructan- modifying enzymes. • Plant fructan-metabolizing enzymes belong to glycoside hydrolase 32 and 68 family. • Enzyme rich plant extract are new valuable approach to fibre modification in food. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (Lolium perenne) is a fructan-accumulating plant constituting one of the most important grassland species with high herbage production, nutritive value and digestibility for grazing cattle. Although fructans were reported to be involved in plant defense acting as antioxidants or stress signals, their contribution in root protection is still to be explored. In roots, atypical defense is provided by the "Root Extracellular Trap" or "RET" at the root-soil interface. The molecular composition and structural organization of the RET are essential to provide root defense against pathogen attacks and abiotic stresses. The RET was reported to be mainly composed of polysaccharides (homogalacturonan, xylogalacturonan, xyloglucan) and proteoglycans such as arabinogalactan proteins (AGPs). Our aim is to characterize the RET composition of L. perenne using cell imaging techniques and a wide range of monoclonal antibodies directed against epitopes from cell wall glycomolecules and to investigate the potential presence of fructans. Interestingly, we found that both mucilage and cell wall surface of border cells were enriched in AGP epitopes. An increased amount of the AGP-containing mucilage was produced by L. perenne root tip in response to both elicitor and osmotic stress. Fructan epitopes were also detected in root cap cells and appeared to be released in the RET under stress conditions. Taken together our findings suggest that AGPs together with fructans are involved in root response of L. perenne to environmental stresses. • The root tip of perennial ryegrass produced border cells of different morphologies. • The root extracellular trap (RET) of perennial ryegrass contained abundant mucilage rich in arabinogalactan protein (AGP). • Fructan epitopes are released within the RET in response to PEG-induced osmotic stress and flagellin 22 elicitation. • Fructans, together with AGPs are promising candidates in root response to environmental stress in perennial ryegrass. [ABSTRACT FROM AUTHOR]

Inulin consumption in both humans and animal models is recognized for its prebiotic action with the most consistent change that lies in enhancing the growth and functionality of Bifidobacterium bacteria, as well as its effect on host gene expression and metabolism. Further, inulin-type fructans are utilized in the colon by bacterial fermentation to yield short-chain fatty acids (SCFAs), which play important role in its biological effects both locally inside the gut and in systemic actions. The gut symbiosis sustained by inulin supplementation among other dietary fibers exerts preventive and/or therapeutic options for many metabolic disorders including obesity, type 2 diabetes mellitus, cardiometabolic diseases, kidney diseases and hyperuricemia. Although, gastrointestinal negative effects due to inulin consumption were reported, such as gastrointestinal symptoms in humans and exacerbated inflammatory bowel disease (IBD) in mice. This comprehensive review aims to present the whole story of how inulin functions as a prebiotic at cellular levels and the interplay between physiological, functional and immunological responses inside the animal or human gut as influenced by inulin in diets, in context to its structural composition. Such review is of importance to identify management and feed strategies to optimize gut health, for instance, consumption of the tolerated doses to healthy adults of 10 g/day of native inulin or 5 g/day of naturally inulin-rich chicory extract. In addition, inulin-drug interactions should be further clarified particularly if used as a supplement for the treatment of degenerative diseases (e.g., diabetes) over a long period. The combined effect of probiotics and inulin appears more effective, and more research on this synergy is still needed. [Display omitted] • Inulin-gut microbiota interactions exert health benefits to the host. • Inulin dietary fiber consumption has a positive role in gut homeostasis and immunity. • Dietary inulin-based plans are potential preventative/therapeutic for metabolic disorders. • The synergy between inulin and prebiotics, probiotics or drugs should be considered. • Inulin and its derivatives are effective as adjuvants in vaccine preparations. [ABSTRACT FROM AUTHOR]

The present work reported the extraction, purification and characterization of an inulin fructan from Codonopsis pilosula (CPW1) and its application in stabilization of selenium nanoparticles (SeNPs). The morphology, stability, and stabilization mechanism of CPW1 stabilized SeNPs (CPW1-Se) were explored, and the results showed that the SeNPs were amorphous state, with size of 54–79 nm, and kept stable within 15 days due to the interaction between SeNPs and the hydroxyl groups on the surface of CPW1. Moreover, the effects on proliferation and apoptosis of CPW1-Se to both normal cells (293T) and liver cancer cells (Huh-7 and HepG2) were evaluated systematically by using the CCK8 assay, plate clone formation assay, flow cytometry and western blot. The results indicated that CPW1-Se possessed selective anti-hepatoma activities without side effects on normal cells, which exhibited strong potential application in liver cancer treatments. [ABSTRACT FROM AUTHOR]

Agave fructans are natural reserve carbohydrates in agave plants. These polysaccharides are composed of blends of fructose polymers with different degrees of polymerization (DP). Today, agave fructans have begun to be used as functional ingredients in various food products due to their technological properties and their favorable impact on health. Agave fructans are healthy ingredients that promote the growth of beneficial bacteria, regulate serum glucose, lessen health problems associated with obesity and overweight, favor calcium absorption, and promote chemoprotective, immunomodulatory, and antioxidant effects. This manuscript summarizes studies on the nutrition and health impacts of agave fructan consumption, followed by a summary of the most relevant food applications and the development of functional foods. Scientific findings suggest that agave fructans can be used to treat and prevent different diseases, including colorectal cancer, overweight, obesity, diabetes, and osteoporosis, and have brain protection properties. These studies will accelerate the development of new functional food products to satisfy consumers' demands and expectations. The development of new products requires detailed knowledge of the physicochemical properties, interactions, and limitations of agave fructans as techno-functional ingredients. Agave fructans are ingredients that improve flavor, color, texture, sweetness, and sensory attributes. Their high solubility and compatibility with different foods make agave fructans ideal ingredients for several applications, including encapsulation and snack products, baked goods, dairy products, beverages, and fruit preserves. • The health and food applications on agave fructans are overviewed. • Agave fructans help to improve food quality and sensory attributes. • Agave fructans can be supplemented for disease prevention. [ABSTRACT FROM AUTHOR]

Yacon roots contain remarkable amounts of prebiotic fructans and rare antioxidant phenolics. Plant-based foods present a short shelf-life. In the case of yacon, fresh storage causes rapid depolymerization of fructans. Therefore, many attempts to extend yacon roots shelf-life have been made over the last years. This review aims at presenting the effect of processing methods on yacon roots health-promoting compounds, such as fructooligosaccharides, inulin and phenolics. Additionally, yacon-based products health-promoting properties, such as antioxidant enzymes activity, lipid peroxidation inhibition and other metabolic parameters that reflect intestinal health, are presented. An overview of the impact of processing on health-promoting compounds retention/concentration is shown. Yacon-based products with higher values of health-promoting properties are pointed out. Innovations have been incorporated in the main methods used for processing yacon along the years, namely drying and blanching, such as the use of vacuum, foam-mat drying, use of salts and acids in the blanching solution, and combination between blanching and drying. Results show that fructan retention was superior when using hot air drying preceded by blanching with salts and acids. Phenolic content in solids was higher when using spray drying. Phenolic content in liquids was higher when using blanching combined with lactobionic acid addition to the juice. In addition, yacon-based products, especially flours, promote intestinal health by means of affecting metabolic parameters like microbial counts, short-chain fatty acids content, antioxidant enzymes expression and postprandial glycemic response. • Yacon roots contain high amounts of prebiotic inulin-type fructans and rare phenolics. • The best fructan retention is achieved by drying preceded by blanching with salts and acids. • The highest phenolic content in solids is achieved by spray drying. • The highest phenolic content in liquids is achieved by blanching combined with acid addition. • The yacon-based products with best health-promoting properties are flours. [ABSTRACT FROM AUTHOR]

Kombucha is prepared by fermenting sugared green or black tea with a symbiotic culture of bacteria and yeast (SCOBY). Some of the bacteria within the SCOBY are known to form exopolysaccharides (EPS) from sucrose. However, it is yet unknown whether water-soluble EPS are formed in kombucha, and if so, which specific EPS are present. Therefore, different kombucha samples were prepared by fermentation of green and black tea with SCOBYs from different manufacturers. Subsequently, the EPS were isolated and characterized by using various chromatographic methods, partial enzymatic hydrolyses and NMR spectroscopy. It was demonstrated that levans with a varying degree of branching at position O 1 (4.3–7.9 %) are present, while only trace amounts of glucans were detected. Furthermore, levans isolated from kombucha had a comparably low molecular weight and the content of levan within the kombucha samples varied from 33 to 562 mg levan/L kombucha. Therefore, our study demonstrated that levans are the main EPS type in kombucha and that levan amounts and structures varied when different starter cultures and ingredients were used. Furthermore, we provide a comprehensive data set on the structural variability of levans from kombucha. [ABSTRACT FROM AUTHOR]

[Display omitted] • CHCA-BA is an optimal matrix for analyzing inulin extracts in plants by MALDI-MRMS. • Chicory inulin powder is an appropriate inulin standard for quantifying DP 9–22. • MALDI-MRMS can rapidly and reliably quantify each DP of inulin in plants. • The DP range length ranked as follows: elephant garlic > globe artichoke > Jerusalem artichoke > yacón. • The inulin content ratio, relative to globe artichoke, is 1:2:3 for yacón, elephant garlic and Jerusalem artichoke. Inulin, a polysaccharide characterized by a β-2,1 fructosyl-fructose structure terminating in a glucosyl moiety, is naturally present in plant roots and tubers. Current methods provide average degrees of polymerization (DP) but lack information on the distribution and absolute concentration of each DP. To address this limitation, a reproducible (CV < 10 %) high throughput (<2 min/sample) MALDI-MRMS approach capable of characterizing and quantifying inulin molecules in plants using matched-matrix consisting of α-cyano-4-hydroxycinnamic acid butylamine salt (CHCA-BA), chicory inulin-12C and inulin-13C was developed. The method identified variation in chain lengths and concentration of inulin across various plant species. Globe artichoke hearts, yacón and elephant garlic yielded similar concentrations at 15.6 g/100 g dry weight (DW), 16.8 g/100 g DW and 17.7 g/100 g DW, respectively, for DP range between 9 and 22. In contrast, Jerusalem artichoke demonstrated the highest concentration (53.4 g/100 g DW) within the same DP ranges. Jerusalem artichoke (DPs 9–32) and globe artichoke (DPs 9–36) showed similar DP distributions, while yacón and elephant garlic displayed the narrowest and broadest DP ranges (DPs 9–19 and DPs 9–45, respectively). Additionally, qualitative measurement for all inulin across all plant samples was feasible using the peak intensities normalized to Inulin-13C, and showed that the ratio of yacón, elephant garlic and Jerusalem was approximately one, two and three times that of globe artichoke. This MALDI-MRMS approach provides comprehensive insights into the structure of inulin molecules, opening avenues for in-depth investigations into how DP and concentration of inulin influence gut health and the modulation of noncommunicable diseases, as well as shedding light on refining cultivation practices to elevate the beneficial health properties associated with specific DPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • DP of fructan is one of the most crucial factors in deciding its properties. • Production of fructan with designed DP by transgenic plants is emphasized. • Biosynthesis of tailor-made fructan is a more promising approach than extraction. • Enzymes and variants used for the synthesis of different fructans are summarized. Fructan, a widespread functional polysaccharide, has been used in the food, pharmaceutical, cosmetic, and material production fields because of its versatile physicochemical properties and biological activities. Inulin from plants and levan from microorganisms are two of the most extensively studied fructans. Fructans from different plants or microorganisms have inconsistent molecular weights, and the molecular weight of fructan affects its properties, functions, and applications. Recently, increasing attention has been paid to the production and application of fructans having various molecular weights, and biotechnological processes have been explored to produce tailor-made fructans from sucrose. This review encompasses the introduction of extraction, enzymatic transformation, and fermentation production processes for fructans with diverse molecular weights. Notably, it highlights the enzymes involved in fructan biosynthesis and underscores their physiological effects, with a special emphasis on their prebiotic properties. Moreover, the applications of fructans with varying molecular weights are also emphasized. [ABSTRACT FROM AUTHOR]

Fructans have long been known with their role in protecting organisms against various stress factors due to their ability to induce controlled dehydration and support membrane stability. Considering the vital importance of such features in cryo-technologies, this study aimed to explore the cryoprotective efficacy of fructans in mammalian cell systems where structurally different fructan polymers were examined on in vitro cell models derived from organs such as the liver, frequently used in transplantation, osteoblast, and cord cells, commonly employed in cell banking, as well as human seminal fluids that are of vital importance in assisted reproductive technology. To gain insights into the fructan/membrane interplay, structural differences were linked to rheological properties as well as to lipid membrane interactions where both fluorescein leakage from unilamellar liposomes and membrane integrity of osteoblast cells were monitored. High survival rates obtained with human endothelial, osteoblast and liver cells for up to two months clearly showed that fructans could be considered as effective non-permeating cryoprotectants, especially for extended periods of cryopreservation. In trials with human seminal fluid, short chained levan in combination with human serum albumin and glycerol proved very effective in preserving semen samples across multiple patients without any morphological abnormalities. [Display omitted] [ABSTRACT FROM AUTHOR]

Fructans are water-soluble polymers of fructose in which fructose units are linked by β-(2 → 1) and/or β-(2 → 6) linkages. In plants, they are synthesized in the vacuole but have also been reported in the apoplastic sap under abiotic stress suggesting that they are involved in plasmalemma protection and in plant-microbial interactions. However, the lack of fructan-specific antibodies currently prevents further study of their role and the associated mechanisms of action, which could be elucidated thanks to their immunolocalization. We report the production of two monoclonal antibodies (named BTM9H2 and BTM15A6) using mice immunization with antigenic compounds prepared from a mixture of plant inulins and levans conjugated to serum albumin. Their specificity towards fructans with β-(2 → 1) and/or β-(2 → 6) linkage has been demonstrated by immuno-dot blot tests on a wide range of carbohydrates. The two mAbs were used for immunocytolocalization of fructans by epifluorescence microscopy in various plant species. Fructan epitopes were specifically detected in fructan-accumulating plants, inside cells as well as on the surface of root tips, confirming both extracellular and intracellular localizations. The two mAbs provide new tools to identify the mechanism of extracellular fructan secretion and explore the roles of fructans in stress resistance and plant-microorganism interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

Fructans, are carbohydrates defined as fructose-based polymers with countable degree of polymerization (DP) ranging so far from DP3 to DP60. There are different types of fructans depending on their molecular arrangement. They are categorized as linear inulins and levans, neoseries of inulin and levan, branched graminans, and highly branched neofructans, so called agavins (Agave carbohydrates). It is worth to note that agavins are the most recently described type of fructans and they are also the most complex ones. The complexity of these carbohydrates is correlated to their various isomers and degree of polymerization range, which is correlated to their multifunctional application in industry and human health. Here, we narrate the story of the agavins' discovery. This included their chemical characterization, their benefits, biotechnological applications, and drawbacks over human health. Finally, a perspective of the study of agavins and their interactions with other metabolites through metabolomics is proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

Levansucrases (LSs) synthesize levan, a β2-6-linked fructose polymer, by successively transferring the fructosyl moiety from sucrose to a growing acceptor molecule. Elucidation of the levan polymerization mechanism is important for using LSs in the production of size-defined products for application in the food and pharmaceutical industries. For a deeper understanding of the levan synthesis reaction, we determined the crystallographic structure of Bacillus subtilis LS (SacB) in complex with a levan-type fructooligosaccharide and utilized site-directed mutagenesis to identify residues involved in substrate binding. The presence of a levanhexaose molecule in the central catalytic cavity allowed us to identify five substratebinding subsites (-1, +1, +2, +3, and +4). Mutants affecting residues belonging to the identified acceptor subsites showed similar substrate affinity (Km) values to the wildtype (WT) Km value but had a lower turnover number and transfructosylation/hydrolysis ratio. Of importance, compared with the WT, the variants progressively yielded smaller-sized low-molecular-weight levans, as the affected subsites that were closer to the catalytic site, but without affecting their ability to synthesized high-molecular-weight levans. Furthermore, an additional oligosaccharide-binding site 20 Å away from the catalytic pocket was identified, and its potential participation in the elongation mechanism is discussed. Our results clarify, for the first time, the interaction of the enzyme with an acceptor/product oligosaccharide and elucidate the molecular basis of the nonprocessive levan elongation mechanism of LSs. [ABSTRACT FROM AUTHOR]

Levan, a β-2,6-glycosidic linked fructan, is a promising alternative for the inulin dominated fructan market. Although levan is already used in some cosmetic products, the commercial availability of the fructan is still limited. Here we show that Gluconobacter japonicus LMG 1417 is a potent levan-forming organism and a promising platform for the industrial production of levan. The levansucrase LevS1417, which is produced by G. japonicus LMG 1417 and secreted by a signal-peptide-independent pathway, exhibited extraordinary high activity (4726 ± 821 U mg−1 at 50 °C). A cell-free levan production based on the supernatant of the investigated strain led to a final levan yield of 157.9 ± 7.6 g L−1. The amount of secreted levansucrase was more than doubled by plasmid-mediated homologous overproduction of LevS1417 in G. japonicus LMG 1417. Accordingly, the space-time yield of cell-free levan production was doubled using the plasmid-bearing mutant. • Gluconobacter japonicus LMG 1417 was identified as a highly efficient levan producer. • The organism produced and secreted a highly active levansucrase (LevS1417). • LevS1417 exhibited extremely high activity (V max > 4500 U mg−1 at 50 °C). • The supernatant of LMG 1417 was used for high-yield cell-free levan production. • Homologous overexpression of LevS1417 doubled the space-time-yield of the process. [ABSTRACT FROM AUTHOR]

β-D-fructofuranosyl glycosidases are enzymes that produce health-beneficial fructooligosaccharides from natural fructans. In a recent issue of JBC, Kashima et al. identified a novel α-D-fructofuranosyl-active enzyme, αFFase1, from the caries-associated bacterium Bifidobacterium dentium. αFFase1 reversibly forms a potential prebiotic also found in caramel, difructose dianhydride I, via intramolecular condensation of the substrate inulobiose. Kashima et al. elegantly combine NMR, X-ray crystallography, and molecular dynamics to describe an original mechanism for the reversible reactions catalyzed by αFFase1 that establishes the new glycoside hydrolase family GH172. [ABSTRACT FROM AUTHOR]

Fructans, such as inulin and fructooligosaccharides (FOS), have several effects on human health owing to their prebiotic character, including anti-microbial and anti-cancer effects, and to their influence on the absorption of minerals, which is very important in childhood and adolescence. Our aim was to review the role of some fructans in the absorption of vitamins and minerals in children and adolescents. We conducted a narrative review of the absorption of nutrients with fructans. We collected quantitative data for our thematic analysis, which was performed using the electronic databases Medline, Lilacs, Web of Science, and Scopus from January 2000 and January 2019. This review comprises a total of 10 articles. Few studies were found regarding the use of prebiotics and nutrient absorption in children. Studies on calcium, iron, magnesium, and vitamin D were the most prevalent. Some studies reported that FOS appears to increase calcium uptake in the gut and stimulates the growth of bifidobacterium in the colon, reducing iron intake by enteric pathogens, and increasing the absorption of these minerals. Others reported an improvement in the absorption of vitamin D and E with inulin. Consumption of fructans improves the health of the microbiota, altering the absorption of some nutrients. [ABSTRACT FROM AUTHOR]

Polygonatum sibiricum is an edible plant species in China known for its abundant polysaccharides. However, correlations between its analytical methods and fine structure have not been established. This is usually due to incomplete cleavage of the glycosidic linkages and instability of hydrolysis. In this study, a new optimal acid hydrolysis method for monosaccharide composition (2 M H 2 SO 4 for 1 h) and methylation analysis (2 mol TFA hydrolysis at 100 °C for 1 h) was developed for characterization of inulin-type fructans, resulting in significantly improved monosaccharide recovery and providing more reliable methylation data. The effectiveness of this method was demonstrated through its application to the study of polysaccharide from P. sibiricum (IPS-70S). The results showed that IPS-70S with a molecular weight of 3.6 kDa is an inulin-type fructans consisting of fructose and glucose in a molar ratio of 27:1. Methylation and NMR analysis indicated that IPS-70S contains →2)-Fru f -(6 → or →2)-Fru f -(1 → with branching →1,6)-Fru f -(2 → and terminates in Glc p -(1 → or Fru f -(2→. In conclusion, optimal acid hydrolysis applicable to the specific polysaccharides contribute to its structurally characterized. The newly optimized acid hydrolysis method for monosaccharide composition and methylation analysis offers a reliable and effective approach to the structural characterization of inulin-type fructans from P. sibiricum. Providing reliable basis for the overall work of NMR analysis and structural analysis, which have potential significance in the field of polysaccharides structural characterization. [Display omitted] [ABSTRACT FROM AUTHOR]

Platycodon grandiflorum (PG) has been widely applied as a conductant drug by ancient and modern traditional Chinese medicine practitioners during long-term clinical practice. However, determining how to guide other medicines to the targeted lungs in traditional Chinese medicine (TCM) prescription remains unclear. An ethanol soluble fraction (Fr. B) was obtained by macroporous resin and 75 % ethanol precipitate. The components were unambiguously determined as fructooligosaccharides and small molecule weight (M w) fructans according to HILIC-ESI−-MS/MS, MS/MS and 1/2D NMR. We discovered that the Fr. B possesses the lung-oriented guidance and targetability by activating Golgi apparatus and endoplasmic reticulum (Golgi-ER) transport system. Rab21, a highly expressed transmembrane protein in the lungs, was found to be the core-affinity target of Fr. B which physically colocalized with the Golgi-ER and directly interacted with Rab21 to accelerate the uptake of extracellular therapeutic substances. The lung-oriented guidance and targetability of Fr. B was validated by the transient knockdown and overexpression of Rab21 considering dynamic observations of colocalization interactions among Fr. B, extracellular substances, and the Golgi-ER. Together, our results delineate a potential mechanism of Fr. B toward lung-oriented guidance and targetability via a direct targeting affinity of Rab21 and resulting collective stimulation of key Golgi-ER transport effectors for the acceleration of extracellular substances into the lungs. [Display omitted] [ABSTRACT FROM AUTHOR]

Levan is an enzymatically synthesized fructose polymer with widely reported structural heterogeneity depending on the producing levansucrase, the reaction conditions employed for its synthesis and the characterization techniques. We studied here the specific properties of levan produced by recombinant levansucrase from B. subtilis 168 (Bs -SacB), often characterized as a bimodal distribution, that is, a mixture of low and high molecular weight levan. We found significant differences between both levans in terms of the already reported molecular weight, size and morphology using different analytical methods. The low molecular weight levan consists of a non-uniform polymer ranging from 50 to 230 kDa, synthesized through a non-processive mechanism that can spontaneously form spherical nanoparticles in the reaction medium. In contrast, high molecular weight levan is a uniform polymer, most probably synthesized through a processive mechanism, with an average molecular weight of 30,750 kDa and a poorly defined nano-structure. This is the first report exploring differences in morphology between low and high molecular weight levans. Our findings demonstrate that only the low molecular weight levan forms spherical nanoparticles in the reaction medium and that high molecular weight levan is mainly composed of a 33,000 kDa fraction with a microgel behavior. [Display omitted] [ABSTRACT FROM AUTHOR]

Several lactic acid bacteria are able to produce water-soluble and water-insoluble homoexopolysaccharides (HoEPS) from sucrose. In this study, structures of all HoEPS which were fermentatively produced by Leuconostoc mesenteroides subsp. dextranicum NRRL B-1121 and B-1144, Leuconostoc mesenteroides subsp. mesenteroides NRRL B-1149, B-1438 and B-1118, Leuconostoc suionicum DSM 20241, and Liquorilactobacillus satsumensis DSM 16230 were systematically analyzed. Monosaccharide analysis, methylation analysis, NMR spectroscopy, size-exclusion chromatography, and different enzymatic fingerprinting methods were used to obtain detailed structural information. All strains produced water-soluble dextrans and/or levans as well as water-insoluble glucans. Levans showed different degrees of branching and high molecular weights, whereas dextrans had comparable structures and broader size distributions. Fine structures of water-soluble HoEPS were analyzed after endo -dextranase and endo -levanase hydrolysis. Water-insoluble glucans were composed of different portions of 1,3-linkages (5 to 40 %). Hydrolysis with endo -dextranase and endo -mutanase yielded further information on block sizes and varying fine structures. Overall, clear differences between HoEPS yields and structures were observed. [Display omitted] [ABSTRACT FROM AUTHOR]

Levans of different structures and molecular weights (MW) can display various techno-functional and health-promoting properties. In the present study, selected levans were produced by the transfructosylation of sucrose catalyzed by levansucrases from Bacillus amyloliquefaciens and Gluconobacter oxydans , and their structural, techno-functional and anti-inflammatory properties were investigated. NMR and methylation/GC analysis confirmed the structure of β-(2, 6) levans. The structural characterization led to the classification of levans as high MW (HMW, ≥100 kDa), low MW (LMW, ≤20 kDa) and mix L/HMW ones. Levan with higher MW had more linear fructosyl units with fewer reducing ends and branching residues. LMW levan showed the highest foaming capacity and stability while HMW levan had the highest emulsion stability. HMW and mix L/HMW levans showed comparable water and oil-holding capacities, which were higher than LMW. HMW and mix L/HMW levans were found to have gelling properties at low concentrations. The rheological behaviour of HMW levan-based gel was a more viscous-like gel, while that of mix L/HMW levan-based one showed more elastic solid like-gel. The temperature also influenced the rheology of levan, showing that the mix L/HMW levan gel network was the most thermal stable as its viscoelasticity remained constant at the highest temperature (75 °C). Studies on the biological activity of levans of HMW and LMW revealed in-vitro anti-inflammatory properties as they significantly reduced the production of LPS-triggered pro-inflammatory cytokines in differentiated Caco-2 cells. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A new PAD electrode management improves signal stabilization for fructans quantification. • PAD turn-off in column wash-regeneration phases avoids gold surface oxidation. • PAD signal stability allows the useful application of ISTD to data normalization. • CL determined opposite results in the growth parameters of chicory leaf and roots. • CL improves fructan content in chicory roots. A new electrode management, within the HPAEC-PAD systems, was proposed to measure inulin-type fructans in chicory roots, grown under two lighting periods: 12 h (T-12 h) and 24 h continuous lighting (T-24 h-CL), with the same daily light integral (DLI). The amperometric cell turn-off (PAD-Off) after elution of carbohydrate of interest, allowed the stabilization of the PAD response, avoiding excessive electrode surface oxidation. The enhanced signal stability allowed the application of fucose as internal standard (ISTD) for data normalization, improving the correctness of linear calibration curves and the quantification of fructans in the case study of chicory plants. T-24 h-CL decreased FW and DW of chicory leaves while increasing these parameters in roots. Fructans amount in chicory roots was significantly higher in the T-24-CL photoperiod. The accuracy of prebiotics quantification by PAD-Off emphasized significant differences between light treatments. CL can improve the yield and quality of chicory roots. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fermentable oligo-, di-, mono-saccharides and polyols (FODMAPs) are prevalent in daily foods like fruits, vegetables, dairy, and grains. • FODMAP intake is consistent regardless of health status. • Only lactose, among FODMAPs, correlates with IBS symptoms. • Individual FODMAP components affect the gut differently. • Understanding FODMAPs can guide dietary recommendations. The present systematic review and meta-analysis summarized data on habitual intake of oligo-, di-, mono-saccharides and polyols from 71 studies (n = 138,653 subjects) using random-effects model. In the general population, overall habitual intake of total FODMAPs is 19.86 (95 % CI: 18.12, 21.6) g/d. No differences were observed on habitual intake of individual constituents of designated FODMAPs between healthy and those who are suffering with functional gastrointestinal disease and other GI disorders. Multiple meta-regression adjusted with macronutrient components showed that IBS-SSS score is positively correlated with lactose (R2 = 77.78 %, P = 0.006) and total FODMAPs (R2 = 78.48 %, P = 0.0052), but not other individual constituents of designated FODMAPs e.g. fructans, GOS, and total polyols. Macronutrient components such as fat (in 6 out of 6 models) and carbohydrate (in 5 out of 6 models) were positively associated with IBS-SSS score. Our findings add insight on current knowledge of FODMAPs habitual intake in the general population and showed that individual FODMAPs such as lactose and other macronutrient components (fat and carbohydrate) as a constituent significantly related to symptom severity. [ABSTRACT FROM AUTHOR]

• Presence of fructosyltransferases correlates with fructan production in Haloarchaea. • Haloarchaea from three different continents were tested for fructanogenic traits. • Fructan production by Archaea was shown for the first time. • Archaeal fructans were characterized via NMR as branched levans and inulins. • Archaeal fructans warrant novel physicochemical properties and applications. Fructans are fructose-based oligo- and polysaccharides derived from sucrose that occur in a plethora of Eubacteria and plants. While fructan-producing (fructanogenic) Eubacteria are abundant in hypersaline environments, fructan production by Archaea has never been reported before. Exopolysaccharides accumulated by various Archaea from the Halobacteria class (belonging to the genera of Halomicrobium, Haloferax and Natronococcus) originating from different locations on Earth were structurally characterized as either levans or inulins with varying branching degrees (10%–16%). Thus, we show for the first time in the literature that fructans are produced in all three domains of life, including Archaea. This proof of concept will not only provide insight into Archaeal glycans and evolution but it may also open new frontiers for innovative strategies to overcome the ever-increasing threat of excessive salinization. [ABSTRACT FROM AUTHOR]

Prebiotic effects of Agave salmiana fructans at five different doses were evaluated by the growth of Bifidobacterium , Lactobacillus , and Clostridium strains and SCFA production in the cecum and proximal colon of healthy Wistar rats. Mucosal integrity, bacterial proliferation, and inflammatory response were also examined. Growth of Bifidobacterium and Lactobacillus strains was improved by 12.5% doses of fructans in both cecum and proximal colon tissues, and a significant decrease of Clostridium (P < 0.05) was observed. Increases in mucosal thickness, proliferation, and cell adhesion were mainly observed in the cecum. High concentration of butyric acid and total SCFA were contained in the 12.5% doses. This study provides direct evidence of the prebiotic effects of Agave salmiana fructans, demonstrating that a diet supplemented with a 12.5% dose of fructans promotes major growth of probiotic bacteria and could be used as a potential prebiotic ingredient under the conditions used in this study. Taken together, these results further indicate the significance of Agave salmiana fructans as a prebiotic ingredient in the regulation and prevention of gastrointestinal diseases, as well as for the design of functional foods. • Prebiotic activity and inflammatory response of Agave salmiana fructans were studied. • The study was performed with healthy rats during 35 days. • The growth of Bifidobacterium and Lactobacillus was monitored by PCR real-time. • Mucosal thickness and cell adhesion combine knowledge of prebiotic effect. [ABSTRACT FROM AUTHOR]

• Fructans are versatile homopolymers with an enormous potential in a wide variety of industrial sectors. • Levansucrases produce fructans of diverse molecular weight, polydispersity and branching ratio. • Traditional and novel strategies to control levan molecular weight are reviewed. • Protein interactions, chemical modifications and protein engineering effects on levan biosynthesis are discussed. • An in-depth analysis of the distinctive structural hallmarks of bacterial levansucrases is provided. The physicochemical properties and biological activity of levan, a generic term given to oligo- and polysaccharides consisting of fructose units linked predominantly by β(2-6) bonds, are attributable to both its size and structural complexity. Branching in β(2-1) contributes to diversify levan structures and properties. There is a broad spectrum of applications for levan and accordingly it has been the subject of several comprehensive reviews. A thorough analysis focused on the product specificity of enzymes from the Glycoside-Hydrolase family 68 that synthesize levan is however missing. We analyze here traditional and novel strategies to manipulate bacterial levansucrases in favor of the generation of low- or high-molecular weight levan, including site directed mutagenesis and chemical engineering. A comparison of highly variable structural elements of levansucrases is presented in the context of their capacity to synthesize saccharides of different sizes, employing the levansucrases from Bacillus subtilis and Bacillus megaterium as references. [ABSTRACT FROM AUTHOR]

Highlights • FOS can be purified by a selective chemical method using phenyl boronic acid. • PBAc react selectively with glucose and fructose to change their polarity. • Only the free fructose pyranose conformer can react with PBAc. • Free furanose and pyranose α-glucose conformers may react with PBAc. • NMR reveals five different glucose-PBAc extraction complexes. Abstract Prebiotic fructooligosaccharides (FOS) are currently obtained by enzymatic reaction with fructosyltransferases (FTFs) using sucrose as both donor and acceptor. In these reactions glucose results as the most abundant by-product, arising from each fructosyl transfer event and, together with fructose, because of the inherent hydrolytic activity of the FTFs. As FOS are mainly used as prebiotic in nutraceutical foods, the reduction or total elimination of monosaccharides is required. In this work the selective elimination of monosaccharides from a synthetic FOS mixture was achieved through the selective complexation of glucose and fructose with phenyl boronic acid (PBAc) followed by ethyl-acetate extraction. The process was applied to a complex mixture of FOS obtained in an enzymatic synthesis reaction containing 40% glucose, 15.8% fructose and 35% of FOS, elimination of the sugars was achieved through 3:1 molar reactions, resulting in a levan-type FOS product with 97% purity. [ABSTRACT FROM AUTHOR]

This study focused on kinetics of levan yield by Bacillus subtilis M, in a 150 L stirred tank bioreactor under controlled pH conditions. The optimized production medium was composed of (g/L): commercial sucrose 100.0, yeast extract 2.0, K 2 HPO 4 3.0 and MgSO 4 ⋅7H 2 O 0.2; an increase in both carbohydrates consumption and cell growth depended on increasing the size of the stirred tank bioreactor from 16 L to 150 L. The highest levansucrase production (63.4 U/mL) and levan yield of 47 g/L was obtained after 24 h. Also, the specific levan yield (Y p/x) which reflects the cell productivity increased with the size increase of the stirred tank bioreactor and reached its maximum value of about 29.4 g/g cells. These results suggested that B. subtilis M could play an important role in levan yield on a large scale in the future. Chemical modifications of B. subtilis M crude levan (CL) into sulfated (SL), phosphorylated (PL), and carboxymethylated levans (CML) were done. The difference in CL structure and its derivatives was detected by FT-IR transmission spectrum. The cytotoxicity of CL and its derivatives were evaluated by HepGII, Mcf-7 and CaCo-2. In general most tested levans forms had no significant cytotoxicity effect. In fact, the carboxymethylated and phosphrylated forms had a lower anti-cancer effect than CL. On the other hand, SL had the highest cytotoxicity showing SL had a significant anti-cancer effect. The results of cytotoxicity and cell viability were statistically analyzed using three-way ANOVA. Image 1 • Scaling up of Bacillus subtilis M levan was done in 150 L fermenter. • It was chemically modified by sulfation, phosphorylation and carboxmethylation. • Cytotoxicity was done on Bacillus subtilis M levan and its derivatives. [ABSTRACT FROM AUTHOR]

While it is well known that the nature of the applied electric field and the heterogeneity of the tissue can influence the impact of PEF treatment on the plant tissues found in plant-based foods, few studies have investigated the influence of PEF on plant structures that are made up of multiple structurally similar organs. The aim of this study was to understand the effect of pulsed electric fields (PEF), at different electric field strengths (0, 0.3, 0.7 and 1.2 kV/cm) and specific energy (7, 21 and 52 kJ/kg), on a multilayered plant material, with bunching onion bulb tissues being used as a model system. The present study found that carbohydrates leakage was an appropriate index to assess PEF induced damage and that plasmolysis of epidermal cells was a good indicator of plasma membrane integrity after PEF. In addition, electric field strength had a greater impact on the cell integrity than specific energy applied. While other studies have shown that different cell types have different sensitivities to PEF, using plasmolysis as an indicator of cell damage, this study clearly showed that the same PEF treatment conditions had a greater effect on the epidermal cells of the outer scales compared to the inner scales. Hence, while different plant cell types vary in their sensitivities to PEF the spatial location of the same cell type within a complex plant material made up of multiple similar organs, i.e. an onion bulb, can also influence how cells respond to the PEF treatment. Despite PEF induced disruption at the cellular level being detected by carbohydrate leakage, the epidermal cell plasmolysis test and by cryo-scanning electromicroscopy (cryo-SEM), no gross structural changes at the organ level were observed using cryo-SEM or fluorescence microscopy. This study also reports for the first time that PEF treatment can enhance fructan leakage from onion bulbs, which means that PEF treatments have the potential to manipulate the fructan contents of some plant-based foods. Unlabelled Image • Electric field strength had a greater impact on cell membrane permeability than specific energy input. • The effect of PEF treatment on epidermal cells increased from the outer to inner scale leaves. • The effect of PEF on the same tissue type depended on the location of the tissue within the same bulb. • Increasing the electric field strength increased fructan leakage. [ABSTRACT FROM AUTHOR]

Highlights • Inulin content is greatly affected during breadmaking. • Polymerization degree of the inulins determines their hydrolysis susceptibility. • Low invertase activity yeasts are recommended for making inulin enriched gluten free breads. Abstract Inulin can improve the nutritional quality of gluten free (GF) bread and have a prebiotic activity. However, breadmaking might frustrate the enrichments efforts due to inulin loss. In this study we aimed at studying the inulin enrichment of GF bread. Two different yeasts [having normal (Y1) or reduced (Y2) invertase activity] were used to leaven the breads enriched with five marketed inulins, which differed for the degree of polymerization (DP) and the manufacturer. Inulin replaced 10% of the rice flour and had low, intermediate or high DP, which ranged from 2 to 20; ≈20; ≥20, respectively. Fructan hydrolysis occurred during leavening of Y1-GF breads, reaching losses up to 40% after baking, depending on the diverse DP of the inulin-forming fructans. Inulin loss was less relevant in Y2-GF breads (up to 5% after baking) than Y1-GF breads. Crumb texture was not negatively influenced by inulin presence, even if this was high (e.g., Y2-GF breads). Information collected within this study may provide further insight to better optimize a GF bread formulation in view of inulin enrichment. [ABSTRACT FROM AUTHOR]

Highlights • Two onion cultivars differ in fructan content and composition in the harvested bulb. • Fructan accumulation and enzymatic activities were examined throughout development. • Fructan accumulation were almost the same in two cultivars before bulb formation. • Varietal differences in the bulb were apparent only 2 or 3 weeks before harvest. • Fructan degradation enzymes would be involved in the varietal differences. Abstract Onion (Allium cepa L.) produces a fructose-based oligosaccharide (fructan) in the bulb as the major reserve carbohydrate. We previously found varietal differences in fructan quantity in the harvested bulbs; 'Kita-momiji 2000' accumulated a high level of fructans with a high degree of polymerization, while 'Pole Star' had low amounts and accumulated mainly monosaccharides and sucrose. In this study, we examined fructan accumulation and enzymatic activities involved in the fructan metabolic pathway in more detail in both aerial and subterranean tissues that were harvested throughout onion development. Analyses of fructan levels in the two cultivars revealed that levels in fructan accumulation were almost the same in aerial and basal leaves before bulb formation, but fructan levels differed significantly in the late stage after bulb formation; varietal differences in fructan content in the harvested bulb were apparent only during the 2 or 3 weeks before harvest. At an early developmental stage, fructan levels in 'Pole Star' were equivalent to those in 'Kita-momiji 2000', indicating that 'Pole Star' can synthesize highly polymerized fructans. In analyses of enzymatic activities, 'Pole Star' had high activity for synthesizing fructan after bulb formation compared to 'Kita-momiji 2000' and also greater potential for degrading sucrose and fructan before bulb formation, leading to less sucrose accumulation both in aerial and basal leaves. These results suggest that high activities for fructan degradation enzymes in 'Pole Star' cause less fructan accumulation in the bulb than in 'Kita-Momiji 2000' because this cultivar cannot sustain high levels of sucrose, the starting substrate for fructan synthesis. [ABSTRACT FROM AUTHOR]

Highlights • Bacterial levan in situ analyzed by enzymatic hydrolysis for the first time. • Levan content estimated from the sugars released by levanase/exoinulinase action. • Possible interference of plant and bacterial origin identified and corrected. • An endoinulinase treatment introduced to detect the presence of interfering inulin. • Applicability demonstrated for levan in wheat and fava bean dough matrices. Abstract Levans and inulins are fructans with mainly β-(2→6) and β-(2→1) linkages, respectively. Levans are produced by many lactic acid bacteria, e.g. during sourdough fermentation. Levans have shown prebiotic properties and may also function as in situ -produced hydrocolloids. So far, levan contents have been measured by acid hydrolysis, which cannot distinguish levans from e.g. inulins. In order to develop a specific analysis for levan in food matrices, a Paenibacillus amylolyticus endolevanase was combined with exoinulinase for levan hydrolysis. A separate endoinulinase treatment was used to detect the possible presence of inulin. Interfering sugars were removed by a pre-wash with aqueous ethanol. Levan content was estimated from fructose and glucose released in the hydrolysis, with a correction made for the residual fructose and glucose-containing sugars. The method was validated using wheat model doughs spiked with commercial Erwinia levan, and tested by analyzing levan content in Leuconostoc mesenteroides DSM 20343-fermented fava bean doughs. [ABSTRACT FROM AUTHOR]

Highlights • Deficit irrigation neither influenced sprouting nor the accumulation of fructans. • Top-to-bottom redistribution of fructans occurred in onion bulb prior to sprouting. • Fructans redistribution could be a predictive marker for onion dormancy-break. • Ethylene and 1-MCP may regulate eco-dormancy; but not endo-dormancy. Abstract Continuous supply of high quality onion bulbs to meet year-round demand is dependent on maintaining dormancy and bulb quality during storage. Sprouting impacts negatively on the storage quality of onion bulbs. Ethylene supplementation has previously been revealed to inhibit sprout growth in stored onion bulbs. Fructans content, especially those at higher degree of polymerisation (DP), are reported to positively correlate with delayed sprouting. However, little is known about the impact of pre-harvest irrigation regimes on fructans accumulation and redistribution in relation to onion bulb dormancy and quality in store. Across two seasons, onion plants of cultivars 'Red Baron' and 'Sherpa' were subjected to full irrigation (FI) (100% replenishment of crop evapotranspiration) or deficit irrigation (DI) (50% of FI treatment) from bulb initiation to harvest. Bulbs were harvested at full maturity and stored at 1 °C for five months. Bulbs were treated with or without 1-MCP (1 μL L−1) for 24 h before storage under continuous ethylene supplementation (10 μL L−1) or air. DI had no effect on dormancy-break, sprout emergence, total fructans content and total sugar content. In contrast, ethylene delayed sprout emergence and suppressed sprout growth; added 1-MCP enhanced this effect. The concentration of DP3-8 fructans were higher in top and bottom sections compared to the baseplate. Before sprout emergence, fructans of DPs 7–8 were no longer present in the top and bottom wedges, while they accumulated in the baseplate; irrespective of pre- or postharvest treatments. This redistribution of fructans within the bulb suggested a transition in dormancy state and could be used as a predictive marker for sprouting in stored onion bulbs. [ABSTRACT FROM AUTHOR]

Abstract Regrowth after defoliation is an essential mechanism of plant tolerance to grazing. In grasses, non-structural carbohydrates (NSC) contained in tiller bases constitute a major substrate for regrowth after defoliation. Using a multi-specific approach, the present study aimed at testing the effect of grazing intensity on NSC concentration in tiller bases. We selected five grazing-tolerant grass species (Agrostis stolonifera , Cynosurus cristatus , Hordeum secalinum, Lolium perenne and Poa trivialis) and collected plants in a grassland subjected to two cattle grazing intensities (intensive versus moderate) for years. We measured NSC concentrations (starch, fructans, sucrose, glucose and fructose) in tiller bases. We found that fructan and sucrose concentrations before the grazing season (April) were higher under intensive than moderate grazing. By contrast, no significant effect of the grazing intensity on these NSC concentrations in tiller bases remained at the end of the grazing season (October). These results suggest that the level of reserves available before the onset of disturbance caused by grazing as well as the reserve replenishment capacity during the grazing season are modified by the intensity of grazing. Highlights • Response of NSC concentrations to grazing intensity was measured for 5 grass species. • Before grazing season, fructan and sucrose concentrations were higher under intensive grazing. • After grazing season, there was no effect of grazing intensity on most NSCs. • Grazing intensity affects both formation and replenishment of NSC reserves. [ABSTRACT FROM AUTHOR]

Abstract In order to understand the effects of sugar metabolism on drought resistance in wheat, two wheat cultivars with different levels of drought resistance were used in this study. We investigated the accumulation pattern of water-soluble carbohydrates (WSC) and expression profiles of twelve fructan metabolism-related genes in peduncle (PED), penultimate (PEN), and lower internode (LOW) stem tissues under drought stress. LH7, a higher drought-resistance cultivar, contained a higher stem dry weight and higher content of WSC in PED, PEN, and LOW tissues, while XN979, a lower drought-resistance cultivar, contained lower values. The tissues from LOW internodes had the highest WSC content, while PED had the lowest. The mRNA levels of genes encoding fructan synthesis-related enzymes, sucrose: sucrose 1-fructosyltransferase (1-SST), sucrose: fructan 6-fructosyltransferase (6-SFT), and fructan: fructan 1- fructosyltransferase (1-FFT) showed higher expression levels at early time points following stress, whilst the genes encoding degradation-related enzymes, fructan exohydrolases (1-FEH), and invertase (INV), showed higher expression at a later time point. Compared with XN979, LH7 showed higher expression levels of genes encoding fructan synthesis-related enzymes at all growth stages, whilst the expression of 1-FEH-W3 , 6-FEH , and INV 3 were higher at a later stage; these expression levels would benefit fructan accumulation and remobilization at early and later stages, respectively. Drought stress induced most of fructan metabolism related genes expression level decreasing in LH7 PED, but enhancing in LH7 LOW part at early time points following stress. The results confirm that there are complex, coordinated expression patterns of fructan synthesis- and degradation-related genes in stems under drought stress. In summary, 1–SST-A2 , 6-SFT, 1-FFT-A , 1-FEH-W3 , 6-FEH , and INV 3 play important roles in fructan accumulation. In addition, higher expression of genes related to fructan synthesis and degradation occurs during early and later stages of drought stress, respectively, enhancing the drought resistance of wheat cultivar LH7. [ABSTRACT FROM AUTHOR]

β(2 → 1)-β(2 → 6) branched graminan-type fructans (GTFs) and β(2 → 1) linear fructans (ITFs) possess immunomodulatory properties and protect human intestinal barrier function, however the mechanisms underlying these effects are not well studied. Herein, GTFs and ITFs effects with different degree of polymerization (DP) values on tight junctions (TJs) genes CLDN - 1 , - 2 and - 3 , CDH1 , OCLN and TJP1 were studied in Caco-2 gut epithelial cells, under homeostatic and inflammatory conditions. Also, cytokine production in dendritic cells (DCs) was studied. Higher DP fructans decreased the expression of the pore forming CLDN - 2. Higher DP GTFs enhanced CLDN - 3 , OCLN , and TJP - 1. Fructans prevented mRNA dysregulation of CLDN - 1 , - 2 and - 3 induced by the barrier disruptors A23187 and deoxynivalenol in a fructan-type dependent fashion. The production of pro-inflammatory cytokines MCP-1/CCL2, MIP-1α/CCL3 and TNFα by DCs was also attenuated in a fructan-type dependent manner and was strongly attenuated by DCs cultured with medium of Caco-2 cells which were pre-exposed to fructans. Our data show that specific fructans have TJs and DCs modulating effects and contribute to gut homeostasis. This might serve to design effective dietary means to prevent intestinal inflammation. [Display omitted] • Higher DP fructans decrease expression of the intestinal tight junction protein claudin-2. • Only graminan-type fructans prevent DON-induced dysregulation of claudin-1. • Graminan-type fructans attenuate pro-inflammatory cytokines in dendritic cells. • Cell culture medium from gut cells exposed to the studied fructans attenuates inflammatory responses in dendritic cells. • Graminan- and inulin-type fructans might contribute to prevention of intestinal inflammation. [ABSTRACT FROM AUTHOR]

Based on stimuli in the biological milieu, macrophages can undergo classical activation into the M1 pro-inflammatory (anti-cancer) phenotype or to the alternatively activated M2 anti-inflammatory one. Drug-free biomaterials have emerged as a new therapeutic strategy to modulate macrophage phenotype. Among them, polysaccharides polarize macrophages to M1 or M2 phenotypes based on the surface receptors they bind. Levan, a fructan, has been proposed as a novel biomaterial though its interaction with macrophages has been scarcely explored. In this study, we investigate the interaction of non-hydrolyzed and hydrolyzed Halomonas levan and its sulfated derivative with human macrophages in vitro. Viability studies show that these levans are cell compatible. In addition, RNA-sequencing analysis reveals the upregulation of pro-inflammatory pathways. These results are in good agreement with real time-quantitative polymerase chain reaction that indicates higher expression levels of C-X-C Motif Chemokine Ligand 8 and interleukin-6 genes and the M2-to-M1 reprogramming of these cells upon levan treatment. Finally, cytokine release studies confirm that hydrolyzed levans increase the secretion of pro-inflammatory cytokines and reprogram IL-4-polarized macrophages to the M1 state. Overall findings indicate that Halomonas levans trigger a classical macrophage activation and pave the way for their application in therapeutic interventions requiring a pro-inflammatory phenotype. [Display omitted] [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether the gastroprotective effects of three types of bacterial levans are correlated with their prebiotic-associated anti-inflammatory/antioxidant potentials. Three levans designated as LevAE, LevP, and LevZ were prepared from bacterial honey isolates; purified, and characterized using TLC, NMR, and FTIR. The anti-inflammatory properties of levan preparations were assessed in LPS-stimulated RAW 264.7 cell lines, while their safety and gastroprotective potentials were assessed in Wistar rats. The three levans significantly reduced ulcer number (22.29–70.05 %) and severity (31.76–80.54 %) in the ethanol-induced gastric ulcer model compared to the control (P < 0.0001/each), with the highest effect observed in LevAE and levZ (200 mg/each) (P < 0.0001). LevZ produced the highest levels of glutathione; catalase activity, and the lowest MDA levels (P = 0.0001/each). The highest anti-inflammatory activity was observed in LevAE and levZ in terms of higher inhibitory effect on IL-1β and TNF-α production (P < 0.0001 each); COX2, PGE2, and NF-κB gene expression. The three levan preparations also proved safe with no signs of toxicity, with anti-lipidemic properties as well as promising prebiotic activity that directly correlated with their antiulcer effect. This novel study highlights the implication of prebiotic-mediated systemic immunomodulation exhibited by bacterial levans that directly correlated with their gastroprotective activity. • Three types of levans were prepared from honey bacterial isolates and characterized. • The three levans significantly reduced ulcer number/severity in gastric ulcer model. • Prepared levans inhibited the inflammatory cascade on the transcriptional level. • All levans showed promising anti-lipidemic properties with no signs of toxicity. • The gastroprotective effect of prepared levans was largely prebiotic-specific. [ABSTRACT FROM AUTHOR]

Saccharomyces paradoxus , a native microorganism of the aguamiel, was used successfully for endoinulinase synthesis for agave fructooligasaccharide (FOS) production. We optimized the fermentation parameters to maximize the enzyme synthesis, and we performed enzyme kinetics studies to achieve agave fructans hydrolysis. The results showed that under constant operating conditions (pH 7.7, 40 °C, 175 rpm of agitation, and 0.005 VVM of aeration) results in the production of an enzymatic extract with 49.57 mg/L. This enzymatic extract, when mixed with an agave fructans solution containing 37.8 g/L, allowed us to obtain products with 18% more FOS content the original concentration. The mass spectrum plot shows that the hydrolyzed product contains FOS with a degree of polymerization from 5 to 9 hexose units. These results are promising because they show FOS production from agave and confirm that importance of using native strains in the design of directed fermentation processes. [ABSTRACT FROM AUTHOR]

Saline and hypersaline environments make up the largest ecosystem on earth and the organisms living in such water-restricted environments have developed unique ways to cope with high salinity. As such these organisms not only carry significant industrial potential in a world where freshwater supplies are rapidly diminishing, but they also shed light upon the origins and extremes of life. One largely overlooked and potentially important feature of many salt-loving organisms is their ability to produce fructans, fructose polymers widely found in various mesophilic Eubacteria and plants, with potential functions as storage carbohydrates, aiding stress tolerance, and acting as virulence factors or signaling molecules. Intriguingly, within the whole archaeal domain of life, Archaea possessing putative fructan biosynthetic enzymes were found to belong to the extremely halophilic class of Halobacteria only, indicating a strong, yet unexplored link between the fructan syndrome and salinity. In fact, this link may indeed lead to novel strategies in fighting the global salinization problem. Hence this review explores the unknown world of fructanogenic salt-loving organisms, where water scarcity is the main stress factor for life. Within this scope, prokaryotes and plants of the saline world are discussed in detail, with special emphasis on their salt adaptation mechanisms, the potential roles of fructans and fructosyltransferase enzymes in adaptation and survival as well as future aspects for all fructanogenic salt-loving domains of life. [ABSTRACT FROM AUTHOR]

Background: Inulin-type fructans used in formula have been shown to promote microbiota composition and stool consistency closer to those of breastfed infants and to have beneficial effects on fever occurrence, diarrhea, and incidence of infections requiring antibiotic treatment in infants.Objectives: The primary study aim was to explore whether prophylactic supplementation with prebiotic fructans is able to influence the frequency of infectious diseases in kindergarten children during a winter period. A secondary objective was to ascertain the effect on the intestinal microbiota.Methods: 142 boys and 128 girls aged 3-6 y were randomly allocated to consume 6 g/d fructans or maltodextrin for 24 wk. At baseline, stool samples were collected for microbiota analysis and anthropometric measurements were made. During the intervention period diagnoses were recorded by physicians, whereas disease symptoms, kindergarten absenteeism, dietary habits, and stool consistency were recorded by parents. Baseline measurements were repeated at wk 24.Results: In total 219 children finished the study. Both the relative abundance of Bifidobacterium (P < 0.001) and that of Lactobacillus (P = 0.014) were 19.9% and 7.8% higher, respectively, post data normalization, in stool samples of children receiving fructans as compared with those of controls at wk 24. This was accompanied by significantly softer stools within the normal range in the prebiotic group from wk 12 onwards. The incidence of febrile episodes requiring medical attention [0.65 ± 1.09 compared with 0.9 ± 1.11 infections/(24 wk × child), P = 0.04] and that of sinusitis (0.01 ± 0.1 compared with 0.06 ± 0.25, P = 0.03) were significantly lower in the prebiotic group. The number of infectious episodes and their duration reported by parents did not differ significantly between the 2 intervention groups.Conclusions: Prebiotic supplementation modified the composition of the intestinal microbiota and resulted in softer stools in kindergarten-aged children. The reduction in febrile episodes requiring medical attention supports the concept of further studies on prebiotics in young children. This trial was registered at clinicaltrials.gov as NCT03241355. [ABSTRACT FROM AUTHOR]