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Intricate ecosystem of the human gut microbiome is affected by various environmental factors, genetic makeup of the individual, and diet. Specifically, resistant starch (RS) is indigestible in the small intestine but nourishes the gut microbiota in the colon. Degradation of RS in the gut begins with primary degraders, such as Bifidobacterium adolescentis and Ruminococcus bromii. Recently, new RS degraders, such as Ruminococcoides bili, have been reported. These microorganisms play crucial roles in the transformation of RS into short-chain fatty acids (SCFAs), such as acetate, propionate, and butyrate. SCFAs are necessary to maintain optimal intestinal health, regulate inflammation, and protect against various illnesses. This review discusses the effects of RS on gut and highlights its complex interactions with gut flora, especially the Ruminococcaceae family.
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Here, we investigated the complexation of short chain amylose (SCAs) and palmitic acid (PA), serving as polymeric building blocks that alter the selectivity and directionality of particle growth. This alteration affects the shape anisotropy of the particles, broadening their applications due to the increased surface area. By modifying the concentration of PA, we were able to make spherical, macaron, and disc-shaped particles, demonstrating that PA acts as a structure-directing agent. We further illustrated the lateral and longitudinal stacking kinetics between PA-SCA inclusion complexes during self-assembly, leading to anisotropy. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed the structural difference between the initial and final morphologies of palmitic acid-short chain amylose particles (PA-SCAPs) compared to those of short-chain amylose particle (SCAPs). The presence of PA-SCA inclusion complex in the anisotropic particles was confirmed using nuclear magnetic resonance (NMR) and powder x-ray diffraction (XRD) analysis.
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The fecal microbiota of two healthy adults was cultivated in a medium containing commercial fructooligosaccharides [FOS; 1-kestose (GF2), nystose (GF3), and 1F-fructofuranosylnystose (GF4)]. Initially, the proportions of lactobacilli in the two feces samples were only 0.42% and 0.17%; however, they significantly increased to 7.2% and 4.8%, respectively, after cultivation on FOS. Most FOS-utilizing isolates could utilize only GF2; however, Lacticaseibacillus paracasei strain Lp02 could fully consume GF3 and GF4 too. The FOS operon (fosRABCDXE) was present in Lc. paracasei Lp02 and another Lc. paracasei strain, KCTC 3510T, but fosE was only partially present in the non-FOS-degrading strain KCTC 3510T. In addition, the top six upregulated genes in the presence of FOS were fosABCDXE, particularly fosE. FosE is a ß-fructosidase that hydrolyzes both sucrose and all three FOS. Finally, a genome-based analysis suggested that fosE is mainly observed in Lc. paracasei, and only 13.5% (61/452) of their reported genomes were confirmed to include it. In conclusion, FosE allows the utilization of FOS, including GF3 and GF4 as well as GF2, by some Lc. paracasei strains, suggesting that this species plays a pivotal role in FOS utilization in the human gut.
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Heces , Microbioma Gastrointestinal , Lacticaseibacillus paracasei , Oligosacáridos , beta-Fructofuranosidasa , Humanos , Oligosacáridos/metabolismo , Heces/microbiología , Lacticaseibacillus paracasei/metabolismo , Lacticaseibacillus paracasei/genética , beta-Fructofuranosidasa/metabolismo , beta-Fructofuranosidasa/genética , Adulto , Operón , Trisacáridos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismoRESUMEN
Amylosucrase (ASase) efficiently biosynthesizes α-glucoside using flavonoids as acceptor molecules and sucrose as a donor molecule. Here, ASase from Deinococcus wulumuqiensis (DwAS) biosynthesized more naringenin α-glucoside (NαG) with sucrose and naringenin as donor and acceptor molecules, respectively, than other ASases from Deinococcus sp. The biotransformation rate of DwAS to NαG was 21.3% compared to 7.1-16.2% for other ASases. Docking simulations showed that the active site of DwAS was more accessible to naringenin than those of others. The 217th valine in DwAS corresponded to the 221st isoleucine in Deinococcus geothermalis AS (DgAS), and the isoleucine possibly prevented naringenin from accessing the active site. The DwAS-V217I mutant had a significantly lower biosynthetic rate of NαG than DwAS. The kcat/Km value of DwAS with naringenin as the donor was significantly higher than that of DgAS and DwAS-V217I. In addition, NαG inhibited human intestinal α-glucosidase more efficiently than naringenin.
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Proteínas Bacterianas , Biotransformación , Deinococcus , Flavanonas , Glucósidos , Glucosiltransferasas , Inhibidores de Glicósido Hidrolasas , Flavanonas/metabolismo , Flavanonas/química , Deinococcus/enzimología , Deinococcus/metabolismo , Deinococcus/química , Deinococcus/genética , Glucosiltransferasas/metabolismo , Glucosiltransferasas/química , Glucosiltransferasas/genética , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/metabolismo , Inhibidores de Glicósido Hidrolasas/farmacología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Glucósidos/metabolismo , Glucósidos/química , Simulación del Acoplamiento Molecular , Cinética , alfa-Glucosidasas/metabolismo , alfa-Glucosidasas/químicaRESUMEN
α-Glucan microparticles (GMPs) have significant potential as high-value biomaterials in various industries. This study proposes a bottom-up approach for producing GMPs using four amylosucrases from Bifidobacterium sp. (BASs). The physicochemical characteristics of these GMPs were analyzed, and the results showed that the properties of the GMPs varied depending on the type of enzymes used in their synthesis. As common properties, all GMPs exhibited typical B-type crystal patterns and poor colloidal dispersion stability. Interestingly, differences in the physicochemical properties of GMPs were generated depending on the synthesis rate of linear α-glucan by the enzymes and the degree of polymerization (DP) distribution. Consequently, we found differences in the properties of GMPs depending on the DP distribution of linear glucans prepared with four BASs. Furthermore, we suggest that precise control of the type and characteristics of the enzymes provides the possibility of producing GMPs with tailored physicochemical properties for various industrial applications.
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Bifidobacterium , Glucanos , Guanosina Monofosfato , Tionucleótidos , Glucanos/química , GlucosiltransferasasRESUMEN
Recently, unconventional yeasts have become popular as fermentation starters in the brewing industry due to the growing consumer demand for aromatic diversity. Specifically, Schizosaccharomyces japonicus has been explored as a potential starter culture for beer and wine production because of its distinct brewing characteristics; however, its application in makgeolli fermentation has not been tested. Therefore, in the present study, two Sz. japonicus strains (SZJ-1 and SZJ-2) were isolated from natural sources, and their brewing characteristics for makgeolli fermentation were compared with those of commercial S. cerevisiae strain. Although the tested isolates showed a lower fermentation and carbon source consumption rate than control-, their overall alcohol fermentation characteristics were suitable for makgeolli production. Regarding flavor composition, Sz. japonicus-fermented makgeolli possessed more ester compounds (e.g., 2-phenylethyl acetate, ethyl acetate, and ethyl decanoate) than S. cerevisiae-fermented makgeolli. Therefore, Sz. japonicus can be used as an alternative culture starter in makgeolli fermentation. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01265-6.
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[This corrects the article DOI: 10.1007/s10068-019-00686-6.].
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Resistant starch (RS) reaches the large intestine largely intact, where it is fermented by the gut microbiota, resulting in the production of short-chain fatty acids (SCFAs) that have beneficial effects on the human body. Bifidobacteria are a major species widely used in the probiotic field, and are increased in the gut by RS, indicating their importance in RS metabolism in the intestine. Bifidobacteria have a genetic advantage in starch metabolism as they possess a significant number of starch-degrading enzymes and extraordinary three RS-degrading enzymes, allowing them to utilize RS. However, to date, only three species of RS-degrading bifidobacteria have been reported as single isolates B. adolescentis, B. choerinum, and B. pseudolongum. In this review, we describe recent studies on RS utilization by Bifidobacterium, based on their biochemical characteristics and genetic findings. This review provides a crucial understanding of how bifidobacteria survive in specific niches with abundant RS such as the human gut.
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Soybean isoflavone aglycones (SIAs) have many biological activities but are poorly water-soluble in the human body. Glycosylation provides structural diversity to SIAs and can alter their physicochemical properties, including water solubility. An alpha-linked glucosylation of SIA was achieved using amylosucrase from Deinococcus geothermalis. A total of 13 alpha-linked glucosyl SIAs were obtained, and their colors in solution were confirmed. The structures of the isolated compounds were identified by mass spectrometry and multidimensional nuclear magnetic resonance spectroscopy. The amylosucrase transglycosylation formed new isoflavone glycosides with alpha glycosidic bonds at C-7 and/or C-4' of SIAs, followed by the production of isoflavone glycosides with alpha (1 â 6) glycosidic bonds. The products with a glucosyl moiety attached to the C-4' of SIAs were found to be more water-soluble than their counterparts attached to the C-7 and/or beta-linkages. This study suggests a strategy for the synthesis of bioactive compounds with enhanced water solubility through alpha-linked glucosylation.
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Glucósidos , Isoflavonas , Glucósidos/química , Glucosiltransferasas/química , Glicósidos/química , Isoflavonas/química , Glycine max , GlicosilaciónRESUMEN
The 4-α-glucanotransferase (4-α-GTase or amylomaltase) is an essential enzyme in maltodextrin metabolism. Generally, most bacterial 4-α-GTase is classified into glycoside hydrolase (GH) family 77. However, hyperthermophiles have unique 4-α-GTases belonging to GH family 57. These enzymes are the main amylolytic protein in hyperthermophiles, but their mode of action in maltooligosaccharide utilization is poorly understood. In the present study, we investigated the catalytic properties of 4-α-GTase from the hyperthermophile Pyrococcus sp. ST04 (PSGT) in the presence of maltooligosaccharides of various lengths. Unlike 4-α-GTases in GH family 77, GH family 57 PSGT produced maltotriose in the early stage of reaction and preferred maltose and maltotriose over glucose as the acceptor. The kinetic analysis showed that maltotriose had the lowest KM value, which increased amylose degradation activity by 18.3-fold. Structural models of PSGT based on molecular dynamic simulation revealed two aromatic amino acids interacting with the substrate at the +2 and +3 binding sites, and the mutational study demonstrated they play a critical role in maltotriose binding. These results clarify the mode of action in carbohydrate utilization and explain acceptor binding mechanism of GH57 family 4-α-GTases in hyperthermophilic archaea.
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Amylosucrase from Neisseria polysaccharea (NpAS) synthesizes α-1,4 glucan polymer from sucrose. In this study, we coated various botanical sources of raw starch with an α-glucan layer generated by NpAS to improve physicochemical properties. Field-emission scanning electron microscopy demonstrated that all surfaces of the starch granules were successfully coated via the NpAS reaction. X-ray diffraction analysis revealed that the crystallinity decreased and the crystal pattern changed to C-type as an amylose layer formed around the surface of the starch granules. Based on rapid viscosity and differential scanning calorimetry analyses, the gelatinization resistance of the α-glucan-coated starch increased owing to decreased viscosity and increased melting temperature. Therefore, the α-glucans coated the starches by enzymatic reactions of various botanical sources; these have applicability in the food and starch industries owing to various physicochemical properties such as enhanced thermostability. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01113-z.
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Resistant starch (RS) in the diet reaches the large intestine and is fermented by the gut microbiota, providing beneficial effects on human health. The human gut bacterium FMB-CY1 was isolated and identified as a new species closest to Ruminococcus bromii. Ruminococcus sp. FMB-CY1 completely degraded RS including commercial RS types 2, 3, and 4, and generated glucose and maltose; however, it did not assimilate glucose. Genome analysis revealed 15 amylolytic enzymes (Amy) present in FMB-CY1. The evolutionary trees revealed that the Amys were well divided each other. All Amys (4, 9, 10, 12, and 16) containing cohesin and/or dockerin and scaffolding proteins known to be involved in constituting the amylosome, were identified. A new species of Ruminococcus, strain FMB-CY1, was considered to have the ability to form amylosomes for the degradation of RS. This new RS-degrading Ruminococcus species provides insights into the mechanism(s) underlying RS degradation in the human gut. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-01027-2.
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A putative type II pullulanase gene, pulP, was identified in Bifidobacterium adolescentis P2P3. PulP possesses an α-amylase domain at the N-terminus and a pullulanase type I domain at the C-terminus, as well as three carbohydrate-binding modules (one CBM25 and two CBM41s) between them. The native PulP and four truncated mutant recombinant proteins (PulPΔCΔP, PulPΔP, PulPΔAΔC, and PulPΔA), in which each of the two catalytic domains and/or the CBMs were deleted, were produced in Escherichia coli and their specific properties were characterized. The removal of either catalytic domain abolished the corresponding catalytic activity of the wild-type enzyme. Deletion of the C-terminal domain resulted in a drastic decrease in the optimal temperature and thermostability, indicating that the pullulanase domain might be related to the temperature dependency of the enzyme. In addition, the elimination of the CBMs in the mutant proteins led to a loss of binding affinity toward raw substrates as well as the loss of their hydrolysis activities compared to the wild-type enzyme. HPAEC and TLC analyses proved that PulP and its mutants could hydrolyze α-glucans into maltotriose as their main product. These results suggest that PulP may play an important role in α-glucan metabolism in B. adolescentis P2P3.
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Proteínas Bacterianas/metabolismo , Bifidobacterium adolescentis/metabolismo , Microbioma Gastrointestinal/fisiología , Glicósido Hidrolasas/metabolismo , Almidón Resistente/metabolismo , Almidón/metabolismo , Metabolismo de los Hidratos de Carbono/fisiología , Catálisis , Escherichia coli/metabolismo , Glucanos/metabolismo , Hidrólisis , Proteínas Recombinantes/metabolismo , alfa-Amilasas/metabolismoRESUMEN
Diverse flavonoid glycosides are present in the plant kingdom. Advanced technologies have been utilized to synthesize glycosyl flavonoids which exhibit good physicochemical characteristics. Previously, novel isoquercitrin (IQ) mono-, di-, and tri-glucosides (IQ-G1', IQ-G2', and IQ-G3'; atypical IQ-Gs (IQ-Gap)) were synthesized through the reaction of amylosucrase. Here, the regio-selective transglycosylation yields were predicted using response surface methodology for three variables (glucose donor (sucrose; 100-1500 mM), glucose acceptor (IQ; 100-400 µM), and pH (5.0-8.8)) using 1 unit/mL of enzyme at 45 °C; then, the optima were verified according to the experimental responses. Acidity (pH 5.0) was a major contributor for IQ-G1' production (> 50%), and high sucrose concentration (1500 mM) limited IQ-G3' production (< 15%). Low sucrose concentration (100 mM) at pH 7.0 promoted higher glycosyl IQ production (> 30%). Time-course production of IQ-Gap showed an exponential growth with different rates. IQ-Gap was stable under the simulated intestinal conditions compared with typical IQ-Gs. Digestive stable IQ-Gap can be effectively synthesized by modulating reaction conditions; thereby, atypical glycosyl products may contribute to the elucidation of nutraceutical potential of flavonoid glycosides. KEY POINTS: â¢Predictions of RSM were validated for the regio-selective IQ-Gap production. ⢠Time course changes of IQ-Gap indicate non-processive glycosylation of DGAS. ⢠IQ-Gap exceed typical IQ-G in digestive stability at simulated intestinal condition.
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Deinococcus , Glucósidos , Glucosiltransferasas , Quercetina/análogos & derivadosRESUMEN
Amylosucrase (ASase, E.C. 2.4.1.4) is a powerful transglycosylation enzyme that can transfer glucose from sucrose to the hydroxyl (-OH) group of various compounds. In this study, recombinant ASases from Deinococcus geothermalis (DgAS) and Bifidobacterium thermophilum (BtAS) were used to synthesize biosurfactants based on the computational analysis of predicted docking simulations. Successful predictions of the binding affinities, conformations, and three-dimensional structures of three surfactants were computed from receptor-ligand binding modes. DgAS and BtAS were effective in the synthesis of biosurfactants from glyceryl caprylate, glyceryl caprate, and polyglyceryl-2 caprate. The results of the transglycosylation reaction were consistent for both ASases, with glyceryl caprylate acceptor showing the highest concentration, as confirmed by thin layer chromatography. Furthermore, the transglycosylation reactions of DgAS were more effective than those of BtAS. Among the three substrates, glyceryl caprylate glycoside and glyceryl caprate glycoside were successfully purified by liquid chromatography-mass spectrometry (LC-MS) with the corresponding molecular weights.
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Eco-friendly conductive polymer nanocomposites have garnered attention as an effective alternative for conventional conductive nanocomposites. Here, we report the fabrication and optimization of flexible, self-standing, and conductive bacterial cellulose/poly(3,4-ethylene dioxythiophene) (BC/PEDOT) nanocomposites using the vapor phase polymerization (VPP) method. Eco-friendly bacterial cellulose (BC) is used as a flexible matrix, and the highly conductive PEDOT polymer is introduced into the BC matrix to achieve electronic conductivity. We demonstrate that vapor phase polymerized BC/PEDOT composites exhibit more than 10 times lower sheet resistance (18 Ω/square) compared to solution polymerized BC/PEDOT (188 Ω/square). The resultant BC/PEDOT fabricated could be bent up to 100 times and completely rolled up without a notable decrease in electronic performance. Moreover, bent BC/PEDOT films enable operation of a green light-emitting diode (LED) light, indicating the flexibility and stability of conductive BC/PEDOT films. Overall, this study suggests a strategy for the development of eco-friendly, flexible, and conductive nanocomposite films.
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Compuestos Bicíclicos Heterocíclicos con Puentes/química , Celulosa/química , Nanopartículas/química , Polímeros/química , Biomasa , Celulosa/metabolismo , Conductividad Eléctrica , Electrodos , Gluconacetobacter xylinus/metabolismo , Luz , Microscopía Electrónica de Rastreo , Nanocompuestos/química , Polimerizacion , PoliestirenosRESUMEN
Many attempts have been made to obtain natural products with certain glycosidic linkages for improvement of their chemo-physical characteristics. Amylosucrase from Deinococcus geothermalis (DGAS; EC.4.2.1.4) is able to transglycosylate natural products. A model compound, isoquercitrin (IQ; quercetin-3-O-glucoside), was employed for producing new IQ glucosides (IQ-Gs). Treatment of IQ with DGAS produced monoglucoside (IQ-G1'), diglucosides (IQ-G2' and IQ-G2â³), and triglucoside (IQ-G3). Structural analysis by mass and nuclear magnetic resonance spectrometry revealed that three of the four IQ-Gs were unreported new compounds possessing α-1,2-, α-1,4-, and/or α-1,6-glucosidic linkages at the 3-O-glucosyl moiety of IQ. IQ-G2' and IQ-G3 were dominantly produced at pH 5.0 and 7.2 and 1500 and 100 mM sucrose, respectively (yields of total IQ-Gs: 50-97%). Kinetic studies indicated that the production rate was dependent on buffer/pH and sucrose concentration. The diverse transglycosylations were verified with a molecular docking simulation. This study sheds light on methods for simple glycodiversification of natural products using DGAS, which can synthesize diversely branched glycosides by modulating reaction conditions.
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Proteínas Bacterianas , Glicósidos , Proteínas Bacterianas/metabolismo , Deinococcus , Glucosiltransferasas/metabolismo , Glicosilación , Cinética , Simulación del Acoplamiento Molecular , Quercetina/análogos & derivadosRESUMEN
Amylosucrase (ASase, EC.4.2.1.4) is well-known for its distinguishable property of transglycosylation of many flavonoids and phenolics. Quercetin has diverse biological functions, however, its use is limited due to poor solubility and bioavailability. ASase derived from Deinococcus geothermalis (DGAS) showed conditional preference for producing unusual quercetin glucosides (QGs). DGAS produced a variety of QGs including quercetin monoglucosides (QG1), diglucosides (QG2 and QG2'), and triglucoside from quercetin and sucrose. The newly synthesized QG2' was recognized as a novel quercetin isomaltoside with an α-1,6 linkage branched at the -OH of C4' in quercetin by mass and nuclear magnetic resonance spectra. With a higher conversion yield from quercetin to QGs (60-92%), the optimum conditions for producing QG2' were examined under various pH and sucrose concentrations by response surface methodology. QG2' was predominantly produced under acidic conditions (pH 5.0) and at high sucrose concentrations (1000-1500â¯mM). In contrast, QG1 was generated as an intermediate of consecutive glycosylation. Kinetic evaluations indicated that considerable differences of transglycosylation velocities were caused by the pH and buffer salts of the reaction, which had a 3.9-fold higher overall performance (kcat/K'm) of generating QG2' at pH 5 compared to at pH 7. A rationale of unusual transglycosylations was demonstrated with a molecular docking simulation. Taken together, our study demonstrated that ASase can be used to synthesize unusually branched flavonoid glycosides from flavonol aglycones with clear patterns by modulating reaction conditions.
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Proteínas Bacterianas/metabolismo , Deinococcus/enzimología , Glucosiltransferasas/metabolismo , Glicósidos/metabolismo , Quercetina/metabolismo , Proteínas Bacterianas/química , Glucosiltransferasas/química , Glicósidos/química , Glicosilación , Concentración de Iones de Hidrógeno , Cinética , Simulación del Acoplamiento Molecular , Estructura Molecular , Quercetina/química , Solubilidad , Sacarosa/metabolismoRESUMEN
The coffee diterpene kahweol may contribute to the anti-obesity effects of coffee but its physiological effects have yet to be elucidated. Caenorhabditis elegans is used as an animal model in obesity research because its lipid metabolism is conserved in humans. The goal was to investigate kahweol's effects on lipid metabolism in C. elegans. Kahweol at 120 µM reduced fat accumulation by 17% compared to the control, which was associated with a reduced food intake. Kahweol did not reduce fat in eat-2 mutants, which have a disrupted pharynx contraction rate, suggesting that the fat-lowering effects of kahweol were dependent on food intake. Lipid metabolism-related gene homologues of tubby protein (tub-1), enoyl-CoA hydratase (ech-1.1), adipose triglyceride lipase (atgl-1), insulin/insulin-like growth receptor (daf-2), and forkhead box O transcription factor (daf-16) were also associated with changes in food intake by kahweol. Therefore, kahweol's fat-lowering effects are due to a reduction of food intake in C. elegans.
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Caenorhabditis elegans/efectos de los fármacos , Caenorhabditis elegans/fisiología , Diterpenos/farmacología , Animales , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Ingestión de Alimentos/efectos de los fármacos , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismoRESUMEN
Butein, a flavonoid found in annatto seeds and lacquer trees, may be used for many health benefits, including the prevention of obesity. However, its anti-obesity effects are not completely understood; in particular, the effects of butein on the regulation of lipid metabolism have not been explained. Thus, the goal of the current study was to determine the effects of butein on lipid metabolism in Caenorhabditis elegans, which is a multi-organ nematode used as an animal model in obesity research. Butein at 70 µM reduced triglyceride content by 27% compared to the control without altering food intake and energy expenditure. The reduced triglyceride content by butein was associated with the downregulation of sbp-1, fasn-1, and fat-7, the lipogenesis-related homologs of sterol regulatory element-binding proteins, fatty acid synthase and stearoyl-CoA desaturase, respectively. Furthermore, fat-7 and skn-1, a homolog of nuclear respiratory factors, were identified as genetic requirements for butein's effects on triglyceride content in C. elegans. The effects of butein on sbp-1 and fasn-1 were dependent on skn-1, but the downregulation of fat-7 was independent of skn-1. These results suggest that the inhibitory effects of butein on lipogenesis are via SKN-1- and FAT-7-dependent pathways in C. elegans.