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International Journal of Molecular... Apr 2023Probiotics provide a range of health benefits. Several studies have shown that using probiotics in obesity treatment can reduce bodyweight. However, such treatments are...
Probiotics provide a range of health benefits. Several studies have shown that using probiotics in obesity treatment can reduce bodyweight. However, such treatments are still restricted. , an epiphytic bacterium, is widely used in a variety of biological applications. However, few studies have investigated the role of spp. in adipocyte differentiation and its molecular mechanisms. Therefore, the objective of this study was to determine the effects of cell-free metabolites of (LSC) on adipogenesis, lipogenesis, and lipolysis in 3T3-L1 adipocytes. The results showed that LSC treatment reduced the accumulation of lipid droplets and expression levels of CCAAT/ enhancer-binding protein-α & β (C/EBP-α & β), peroxisome proliferator-activated receptor-γ (PPAR-γ), serum regulatory binding protein-1c (SREBP-1c), adipocyte fatty acid binding protein (aP2), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), resistin, pp38MAPK, and pErk 44/42. However, compared to control cells, adiponectin, an insulin sensitizer, was elevated in adipocytes treated with LSC. In addition, LSC treatment increased lipolysis by increasing pAMPK-α and suppressing FAS, ACC, and PPAR-γ expression, similarly to the effects of AICAR, an AMPK agonist. In conclusion, is a novel probiotic strain that can be used to treat obesity and its associated metabolic disorders.
Topics: Mice; Animals; Adipogenesis; Lipogenesis; AMP-Activated Protein Kinases; Peroxisome Proliferator-Activated Receptors; Cell Differentiation; Signal Transduction; Obesity; CCAAT-Enhancer-Binding Protein-alpha; Leuconostoc; 3T3-L1 Cells; PPAR gamma
PubMed: 37108530
DOI: 10.3390/ijms24087367 -
Foods (Basel, Switzerland) Dec 2023This review highlights 's promising possibilities as a proficient mannitol producer and its potential implications for sugar reduction, with a focus on its use in... (Review)
Review
This review highlights 's promising possibilities as a proficient mannitol producer and its potential implications for sugar reduction, with a focus on its use in sourdough-based baked good products. Mannitol, a naturally occurring sugar alcohol, has gained popularity in food items due to its low calorie content and unique beneficial qualities. This study summarizes recent research findings and investigates the metabolic pathways and culture conditions that favor increased mannitol production by . Furthermore, it investigates the several applications of mannitol in baked goods, such as its function in increasing texture, flavor and shelf life while lowering the sugar content. Sourdough-based products provide an attractive niche for mannitol integration, as customer demand for healthier and reduced-sugar options increases.
PubMed: 38201124
DOI: 10.3390/foods13010096 -
BMC Biotechnology Feb 2021Levan is a well-known homopolymer of fructose composed predominantly of β-(2, 6) fructofuranosyl linkages in the backbone with occasional β-(2, 1) linkages in the...
BACKGROUND
Levan is a well-known homopolymer of fructose composed predominantly of β-(2, 6) fructofuranosyl linkages in the backbone with occasional β-(2, 1) linkages in the branch chains with varied applications. However, high production cost due to low yield of microbial levan has become a bottleneck for its practical applications. Furthermore, factors affecting the molecular mass of the synthesized levan by Leuconostoc spp. during prolonged cultivation is not fully elucidated.
METHODS
The cultivation condition for Leuconostoc citreum BD1707 to synthesize levan was optimized by single-factor experiments and subsequently with response surface methodology (RSM). The average molecular weight (Mw) of levan synthesized by the strain L.citreum BD1707 under the optimized cultivation conditions was monitored by high-performance size exclusion chromatography (HPSEC). Finally, the enzyme with levan-degrading activity was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).
RESULTS
The levan yield of BD1707 reached 34.86 g/L with a corresponding productivity of 7.47 g/L/d under the optimal cultivation conditions deduced by RSM, i.e., cultivation at 26 °C and 200 rpm for 112 h in tomato juice supplemented with 172 g/L sucrose with an initial pH value of 6.12. The Mw of levan reached a peak value of 2.320 × 10 Da at 6 h of cultivation under the optimized cultivation conditions and then gradually decreased to 8.809 × 10 Da after 120 h of cultivation.
CONCLUSION
The levan yield of the strain L.citreum BD1707 could be sufficiently enhanced via cultivation condition optimization. The decrease in molecular mass of the synthesized levan was attributed predominantly to the hydrolytic activity of levansucrase secreted by L.citreum BD1707 during cultivation, with an estimated Mw of 130 KD by SDS-PAGE, while the effect of acid hydrolysis could be nearly neglected.
Topics: Fructans; Fructose; Glucose; Hexosyltransferases; Hydrogen-Ion Concentration; Leuconostoc; Solanum lycopersicum; Molecular Weight; Sucrose; Temperature
PubMed: 33541325
DOI: 10.1186/s12896-021-00673-y -
Foods (Basel, Switzerland) Feb 2019The aim of this study was the characterization and selection of bacterial strains suitable for the production of a "yeast-free" bread. The strains C2.27 and C5.7 were...
The aim of this study was the characterization and selection of bacterial strains suitable for the production of a "yeast-free" bread. The strains C2.27 and C5.7 were selected for their leavening and acidification capabilities and individually used as starters in bread-making tests. Liquid type-II sourdoughs, singly inoculated with the two selected strains, were characterized and employed for bread-making, through the set-up of a biotechnological protocol without the use of baker's yeast as a leavening agent. Aiming to verify the ability of the selected strains to dominate the fermentation process, bacteria and yeasts were isolated from liquid sourdoughs and doughs, genetically characterized and identified. Both the selected strains were suitable for the production of bread, even if C2.27 showed the highest leavening capacity and was able to dominate the dough microbiota. The effects of different salt concentrations on the selected strain performances were also investigated. The applicability of the developed protocol, adapted for the production of the typical Apulian bread, "puccia", and the suitability of the strain C2.27 were confirmed at pilot scale in an industrial bakery. The puccia bread, which was produced with the liquid sourdough fermented with C2.27, without baker's yeast and salt, was similar in appearance to the conventional product containing baker's yeast and was judged positively by a sensory analysis.
PubMed: 30781845
DOI: 10.3390/foods8020070 -
Microorganisms Feb 2023Infectious diseases caused by bacteria are at risk of spreading and prolonging due to antimicrobial resistance. It is, therefore, urgently necessary to develop a more...
Infectious diseases caused by bacteria are at risk of spreading and prolonging due to antimicrobial resistance. It is, therefore, urgently necessary to develop a more effective antibiotic alternative strategy to control pathogen spread. In general, probiotics have been recommended as a substitute for antibiotics that inhibit pathogens. This study was isolated and probiotic characteristics and antibacterial bacterial efficiency against various infection-causing pathogens were determined by different in vitro methods. A 16S rRNA sequence confirmed that the isolated strains belonged to a species of . KCC-57 and KCC-58 produced various extracellular enzymes and fermented different carbohydrates. There was significant tolerance for both strains under the harsh conditions of the gastrointestinal tract (GIT). In addition, KCC-57 and KCC-58 showed significant auto-aggregations and hydrophobicity properties that varied with incubation time. Moreover, the cell-free secondary supernatant (CFS) of KCC-57 and KCC-58 inhibited growth of , , and According to a co-culture study, KCC-57 and KCC-58 were highly competitive for pathogen growth. KCC-57 and KCC-58 showed significant probiotic potential and strong antibacterial activities against different pathogens, suggesting that these strains could be used instead of antibiotics to control infectious pathogens.
PubMed: 36838434
DOI: 10.3390/microorganisms11020469 -
Applied and Environmental Microbiology Oct 2019Fructophilic lactic acid bacteria (FLAB), composed of spp., , and , are unique in that they prefer d-fructose over d-glucose as a carbon source. Strain F192-5, isolated...
Fructophilic lactic acid bacteria (FLAB), composed of spp., , and , are unique in that they prefer d-fructose over d-glucose as a carbon source. Strain F192-5, isolated from the peel of a satsuma mandarin and identified as , grows well on d-fructose but poorly on d-glucose and produces mainly lactate and acetate, with trace amounts of ethanol, from the metabolism of d-glucose. These characteristics are identical to those of obligate FLAB. However, strain F192-5 ferments a greater variety of carbohydrates than known FLAB. Comparative analyses of the genomes of strain F192-5 and reference strains of revealed no signs of specific gene reductions, especially genes involved in carbohydrate transport and metabolism, in the genome of F192-5. The bifunctional alcohol/acetaldehyde dehydrogenase gene () is conserved in strain F192-5 but is not transcribed. This is most likely due to a deletion in the promoter region upstream of the gene. Strain F192-5 did, however, ferment d-glucose when transformed with a plasmid containing the allochthonous gene. F192-5 is an example of a pseudo-FLAB strain with a deficiency in d-glucose metabolism. This unique phenotypic characteristic appears to be strain specific within the species This might be one of the strategies lactic acid bacteria use to adapt to diverse environmental conditions. Obligate fructophilic lactic acid bacteria (FLAB) lack the metabolic pathways used in the metabolism of most carbohydrates and differ from other lactic acid bacteria in that they prefer to ferment d-fructose instead of d-glucose. These characteristics are well conserved at the genus or species level. F192-5 shows similar growth characteristics. However, the strain is metabolically and genomically different from obligate FLAB. This is an example of a strain that evolved a pseudo-FLAB phenotype to adapt to a fructose-rich environment.
Topics: Alcohol Dehydrogenase; Aldehyde Oxidoreductases; Bacterial Proteins; Citrus; Fructose; Leuconostoc
PubMed: 31399409
DOI: 10.1128/AEM.01077-19 -
International Journal of Molecular... Mar 2021Alternansucrase (ALT, EC 2.4.1.140) is a glucansucrase that can generate α-(1,3/1,6)-linked glucan from sucrose. Previously, the crystal structure of the first...
Alternansucrase (ALT, EC 2.4.1.140) is a glucansucrase that can generate α-(1,3/1,6)-linked glucan from sucrose. Previously, the crystal structure of the first alternansucrase from NRRL B-1355 was successfully elucidated; it showed that alternansucrase might have two acceptor subsites (W675 and W543) responsible for the formation of alternating linked glucan. This work aimed to investigate the primary acceptor subsite (W675) by saturated mutagenesis using ABK-1 alternansucrase (ALT). The substitution of other residues led to loss of overall activity, and formation of an alternan polymer with a nanoglucan was maintained when W675 was replaced with other aromatic residues. Conversely, substitution by nonaromatic residues led to the synthesis of oligosaccharides. Mutations at W675 could potentially cause ALT to lose control of the acceptor molecule binding via maltose-acceptor reaction-as demonstrated by results from molecular dynamics simulations of the W675A variant. The formation of α-(1,2), α-(1,3), α-(1,4), and α-(1,6) linkages were detected from products of the W675A mutant. In contrast, the wild-type enzyme strictly synthesized α-(1,6) linkage on the maltose acceptor. This study examined the importance of W675 for transglycosylation, processivity, and regioselectivity of glucansucrases. Engineering glucansucrase active sites is one of the essential approaches to green tools for carbohydrate modification.
Topics: Enzyme Activation; Glycosylation; Glycosyltransferases; Hydrolysis; Kinetics; Leuconostoc; Models, Molecular; Protein Binding; Protein Conformation; Protein Engineering; Structure-Activity Relationship; Substrate Specificity
PubMed: 33810084
DOI: 10.3390/ijms22063229 -
Journal of Applied Glycoscience 2023Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with...
Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with α-(1→2)-branches and are generated by bacteria. DDE was isolated from (formerly known as sp. M-73) 40 years ago, although the amino acid sequence of the enzyme has not been determined. Herein, we found a gene for this enzyme based on the partial amino acid sequences from native DDE and characterized the recombinant enzyme. DDE had a signal peptide, a glycoside hydrolase family 65 domain, a carbohydrate-binding module family 35 domain, a domain (D-domain) similar to the C-terminal domain of glucodextranase, and a transmembrane region at the C-terminus. Recombinant DDE released glucose from α-(1→2)-branched α-glucans produced by strains B-1299, S-32, and S-64 and showed weak hydrolytic activity with kojibiose and kojitriose. No activity was detected for commercial dextran and B-1355 α-glucan, which do not contain α-(1→2)-linkages. The removal of the D-domain decreased the affinity for α-(1→2)-branched α-glucans but not for kojioligosaccharides, suggesting that D-domain plays a role in α-glucan binding. Genes for putative dextranases, oligo-1,6-glucosidase, sugar-binding protein, and permease were present in the vicinity of the DDE gene, and as a result these gene products may be necessary for the use of α-(1→2)-branched glucans. Our findings shed new light on how actinobacteria utilize polysaccharides produced by lactic acid bacteria.
PubMed: 37033117
DOI: 10.5458/jag.jag.JAG-2022_0013 -
Foods (Basel, Switzerland) Jul 2022Soybean whey is a kind of agricultural by-product enriched with nutritional value but with low utilization. The extracellular polysaccharides secreted by lactic acid...
Soybean whey is a kind of agricultural by-product enriched with nutritional value but with low utilization. The extracellular polysaccharides secreted by lactic acid bacteria during the fermentation possess a variety of structural characteristics and beneficial properties. In this study, an exopolysaccharide (EPS) was isolated from 1.2461 after fermentation in optimized soybean whey-enriched 10% sucrose at 37 °C for 24 h. The water-soluble EPS-1 was obtained by DEAE-52 anion exchange chromatography, and the structural characterization of EPS-1 was investigated. The EPS-1 was homogeneous with an average molecular weight of 4.712 × 10 Da and consisted mainly of glucose. Nuclear magnetic resonance (NMR) spectrum and flourier transform infrared (FT-IR) spectrum indicated that the EPS-1 contained →3)-α-D-Glcp-(1→ and →6)-α-D-Glcp-(1→ residues. The rheological properties of EPS-1 under the conditions of changing shear rate, concentration, temperature and coexisting ions showed its pseudoplastic fluid behaviors. In addition, the EPS-1 exhibited certain scavenging activity on the ABTS radical and chelating activity on metal ions at relatively high concentrations. Furthermore, EPS-1 with a certain concentration was confirmed to have significant protective effects on yeast cell injury induced by hydrogen peroxide. This study reported the structural characteristics of exopolysaccharide from 1.2461 and provides a basis for its potential application in the field of functional foods.
PubMed: 35954049
DOI: 10.3390/foods11152283 -
Applied and Environmental Microbiology Dec 2015A levan-producing strain, BD1707, was isolated from Tibetan kefir and identified as Leuconostoc citreum. The effects of carbon sources on the growth of L. citreum BD1707...
A levan-producing strain, BD1707, was isolated from Tibetan kefir and identified as Leuconostoc citreum. The effects of carbon sources on the growth of L. citreum BD1707 and levan production in tomato juice were measured. The changes in pH, viable cell count, sugar content, and levan yield in the cultured tomato juice supplemented with 15% (wt/vol) sucrose were also assayed. L. citreum BD1707 could synthesize more than 28 g/liter of levan in the tomato juice-sucrose medium when cultured at 30°C for 96 h. Based on the monosaccharide composition, molecular mass distribution, Fourier transform infrared (FTIR) spectra, and nuclear magnetic resonance (NMR) spectra, the levan synthesized by L. citreum BD1707 was composed of a linear backbone consisting of consecutive β-(2→6) linked d-fructofuranosyl units, with an estimated average molecular mass of 4.3 × 10(6) Da.
Topics: Culture Media; Food Microbiology; Fructans; Hydrogen-Ion Concentration; Leuconostoc; Solanum lycopersicum; Magnetic Resonance Spectroscopy; Microbial Viability; Molecular Weight; Spectroscopy, Fourier Transform Infrared; Sucrose; Temperature; Tibet; Time Factors
PubMed: 26682858
DOI: 10.1128/AEM.02944-15