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Food Chemistry Sep 2024The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in...
The wine market has always faced the problem of fraud, including the addition of exogenous sugar solutions to grape musts to increase the final alcohol content. Since in some countries the practice of chaptalization is prohibited (except by adding concentrated must) it is necessary to broaden the analytical techniques that allow the identification of this type of fraud. The aim of this study was to define an NMR-based sugar profile of genuine grape must to set concentration limits for each sugar as parameters of authenticity. Glucose, fructose, together with eleven minor sugars were quantified in 82 genuine Italian grape musts, developing an analytical procedure based on highly selective chemical shift filters followed by TOCSY. Alongside the characteristic myo- and scyllo-inositol, significant contents of mannose, galactose, and trehalose were also found. Otherwise, maltose, rhamnose, arabinose, sucrose and lactose are present in lower concentrations and show great concentration variability.
Topics: Vitis; Magnetic Resonance Spectroscopy; Wine; Sugars; Fruit
PubMed: 38657517
DOI: 10.1016/j.foodchem.2024.139374 -
Bioresources and Bioprocessing Jan 2024The bioconversion of 4-hydroxy-2-keto acid derivatives via aldol condensation of formaldehyde and pyruvate has received substantial attention as potential source of...
The bioconversion of 4-hydroxy-2-keto acid derivatives via aldol condensation of formaldehyde and pyruvate has received substantial attention as potential source of chemicals for production of amino acids, hydroxy carboxylic acids, and chiral aldehydes. We developed an environmentally friendly biocatalyst consisting of a novel thermostable class II pyruvate aldolase from Deinococcus radiodurans with maltose-binding protein (MBP-DrADL), which has specific activity of 46.3 µmol min mg. Surprisingly, MBP-DrADL maintained over 60% of enzyme activity for 4 days at 50 to 65 °C, we used MBP-DrADL as the best candidate enzyme to produce 2-keto-4-hydroxybutyrate (2-KHB) from formaldehyde and pyruvate via aldol condensation. The optimum reaction conditions for 2-KHB production were 50 °C, pH 8.0, 5 mM Mg, 100 mM formaldehyde, and 200 mM pyruvate. Under these optimized conditions, MBP-DrADL produced 76.5 mM (8.94 g L) 2-KHB over 60 min with a volumetric productivity of 8.94 g L h and a specific productivity of 357.6 mg mg-enzyme h. Furthermore, 2-KHB production was improved by continuous addition of substrates, which produced approximately 124.8 mM (14.6 g L) of 2-KHB over 60 min with a volumetric productivity and specific productivity of 14.6 g L h and 583.4 mg mg-enzyme h, respectively. MBP-DrADL showed the highest specific productivity for 2-KHB production yet reported. Our study provides a highly efficient biocatalyst for the synthesis of 2-KHB and lays the foundation for large-scale production and application of high-value compounds from formaldehyde.
PubMed: 38647973
DOI: 10.1186/s40643-024-00727-x -
Bioresources and Bioprocessing Sep 2023Trehalose is a functional sugar that has numerous applications in food, cosmetic, and pharmaceutical products. Production of trehalose from maltose via a single-step...
Trehalose is a functional sugar that has numerous applications in food, cosmetic, and pharmaceutical products. Production of trehalose from maltose via a single-step enzymatic catalysis using trehalose synthase (TreS) is a promising method compared with the conventional two-step process due to its simplicity with lower formation of byproducts. In this study, a cold-active trehalose synthase (PaTreS) from Pseudarthrobacter sp. TBRC 2005 was heterologously expressed and characterized. PaTreS showed the maximum activity at 20 °C and maintained 87% and 59% of its activity at 10 °C and 4 °C, respectively. The enzyme had remarkable stability over a board pH range of 7.0-9.0 with the highest activity at pH 7.0. The activity was enhanced by divalent metal ions (Mg, Mn and Ca). Conversion of high-concentration maltose syrup (100-300 g/L) using PaTreS yielded 71.7-225.5 g/L trehalose, with 4.5-16.4 g/L glucose as a byproduct within 16 h. The work demonstrated the potential of PaTreS as a promising biocatalyst for the development of low-temperature trehalose production, with the advantages of reduced risk of microbial contamination with low generation of byproduct.
PubMed: 38647947
DOI: 10.1186/s40643-023-00681-0 -
Archives of Microbiology Apr 2024A novel Lysinibacillus strain, designated KH24, was isolated from the gut of Siganus fuscescens, a herbivorous fish, which was captured off the coast of Okinawa, Japan....
A novel Lysinibacillus strain, designated KH24, was isolated from the gut of Siganus fuscescens, a herbivorous fish, which was captured off the coast of Okinawa, Japan. Strain KH24 is a rod-shaped, Gram-stain-positive, spore-forming, and motile bacterium that forms off-white colonies. The 16S rRNA gene sequence of strain KH24 showed the highest similarity (97.4%) with Lysinibacillus pakistanensis JCM 18776 and L. irui IRB4-01. Genomic similarities between strain KH24 and Lysinibacillus type strains, based on average nucleotide identity, digital DNA-DNA hybridization (genome-to-genome distance calculation), and average amino acid identity were 70.4-77.7%, 17.1-24.4%, and 69.2-81.2%, respectively, which were lower than species delineation thresholds. Strain KH24 growth occurred at pH values of 5.5-8.5, temperatures of 20-40 °C, and NaCl concentrations of 0-4.0%, and optimally at pH 7.0, 30 °C, and 0%, respectively. Unlike related Lysinibacillus type strains, strain KH24 could assimilate D-glucose, D-fructose, N-acetyl-glucosamine, amygdalin, arbutin, esculin, ferric citrate, salicin, D-cellobiose, D-maltose, D-sucrose, and gentiobiose. Major fatty acids included iso-C (45.8%), anteiso-C (15.1%), iso-C (12.6%), and anteiso-C (10.9%). Menaquinone-7 was the predominant quinone, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and lysophosphatidylethanolamine. Based on its genetic and phenotypic properties, strain KH24 represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus piscis sp. nov. is proposed. The type strain is KH24 (= JCM 36611 = KCTC 43676).
Topics: Animals; RNA, Ribosomal, 16S; Acetylglucosamine; Amino Acids; Amygdalin; DNA
PubMed: 38643446
DOI: 10.1007/s00203-024-03937-1 -
Molecular Biology Reports Apr 2024Post-harvest anthracnose (PHA) of mango is a devastating disease, which results in huge loss to mango producers and importers. Various species of PHA, diverse...
BACKGROUND
Post-harvest anthracnose (PHA) of mango is a devastating disease, which results in huge loss to mango producers and importers. Various species of PHA, diverse pathogenicity, and different resistance towards fungicides make it essential to evaluate the pathogen taxonomic status and biological characterization.
METHODS AND RESULTS
Two strains DM-1 and DM-2 isolated from the fruit of DaQing mango from Vietnam were identified as Colletotrichum fructicola and C. asianum respectively, based on the morphological features, along with the phylogenetic tree of ITS and ApMat combined sequences. The growth status of different Colletotrichum strains under different conditions was analyzed to reveal the biological characteristics. The optimum growth temperature of DM-1 and DM-2 was 28 °C and mycelia grew rapidly in the dark. Both strains could grow in media with pH 4-11, while the optimum pH value was 6. Maltose and soluble starch were the most suitable carbon source for DM-1 and DM-2 respectively, and the peptone was the most suitable nitrogen source for both strains. The lethal temperatures were recorded as 55 °C 5 min for DM-1, and 50 °C 10 min for DM-2.
CONCLUSIONS
To the best of our knowledge, it is the first study reporting the identification of the pathogens: C. fructicola and C. asianum responsible for postharvest fruit anthracnose of mango in Vietnam.
Topics: Mangifera; Colletotrichum; Phylogeny; Vietnam; Plant Diseases
PubMed: 38643317
DOI: 10.1007/s11033-024-09523-4 -
Molecular Metabolism Jun 2024Hepatic glucose metabolism is profoundly perturbed by excessive alcohol intake. miR-141/200c expression is significantly induced by chronic ethanol feeding. This study...
OBJECTIVE
Hepatic glucose metabolism is profoundly perturbed by excessive alcohol intake. miR-141/200c expression is significantly induced by chronic ethanol feeding. This study aimed at identifying the role of miR-141/200c in glucose homeostasis during chronic ethanol exposure.
METHODS
WT and miR-141/200c KO mice were fed a control or an ethanol diet for 30 days, followed by a single binge of maltose dextrin or ethanol, respectively. Untargeted metabolomics analysis of hepatic primary metabolites was performed along with analyses for liver histology, gene expression, intracellular signaling pathways, and physiological relevance. Primary hepatocytes were used for mechanistic studies.
RESULTS
miR-141/200c deficiency rewires hepatic glucose metabolism during chronic ethanol feeding, increasing the abundance of glucose intermediates including G6P, an allosteric activator for GS. miR-141/200c deficiency replenished glycogen depletion during chronic ethanol feeding accompanied by reduced GS phosphorylation in parallel with increased expression of PP1 glycogen targeting subunits. Moreover, miR-141/200c deficiency prevented ethanol-mediated increases in AMPK and CaMKK2 activity. Ethanol treatment reduced glycogen content in WT-hepatocytes, which was reversed by dorsomorphin, a selective AMPK inhibitor, while KO-hepatocytes displayed higher glycogen content than WT-hepatocytes in response to ethanol treatment. Furthermore, treatment of hepatocytes with A23187, a calcium ionophore activating CaMKK2, lowered glycogen content in WT-hepatocytes. Notably, the suppressive effect of A23187 on glycogen deposition was reversed by dorsomorphin, demonstrating that the glycogen depletion by A23187 is mediated by AMPK. KO-hepatocytes exhibited higher glycogen content than WT-hepatocytes in response to A23187. Finally, miR-141/200c deficiency led to improved glucose tolerance and insulin sensitivity during chronic ethanol feeding.
CONCLUSIONS
miR-141/200c deficiency replenishes ethanol-mediated hepatic glycogen depletion through the regulation of GS activity and calcium signaling coupled with the AMPK pathway, improving glucose homeostasis and insulin sensitivity. These results underscore miR-141/200c as a potential therapeutic target for the management of alcohol intoxication.
Topics: Animals; Ethanol; Mice; MicroRNAs; Hepatocytes; Liver; Mice, Knockout; Liver Glycogen; Male; Mice, Inbred C57BL; Glucose
PubMed: 38642890
DOI: 10.1016/j.molmet.2024.101942 -
International Journal of Biological... May 2024The subfamily GH13_16 trehalose synthase (TreS) converts maltose to trehalose and vice versa. Typically, it consists of three domains, but it may contain a C-terminal...
The subfamily GH13_16 trehalose synthase (TreS) converts maltose to trehalose and vice versa. Typically, it consists of three domains, but it may contain a C-terminal extension exhibiting clear sequence features of a maltokinase (MaK). The present in silico study was focused on collection of naturally fused TreS-MaKs and their subsequent detailed bioinformatics analysis. Hence a set of total 3354 unique sequences was compared consisting of 1900 single TreSs, 1426 fused TreS-MaKs and 28 single MaKs. Fused TreS-MaKs were divided into five groups, namely with a standard MaK, with mutations in the maltose-binding site, of the catalytic nucleophile, of the general acid/base and of both catalytic residues. Sequence logos bearing the best conserved sequence regions were prepared for both TreSs and MaKs in an effort to find unique sequence features. In addition, linkers connecting the TreS and MaK parts in the fused enzymes were analysed. This analysis revealed that MaKs in fused enzymes have an extended N-terminal regions compared to single MaKs. Finally, the evolutionary relationships were demonstrated by phylogenetic trees of TreS parts from single TreSs and fused TreS-MaKs from the same organism as well as of single TreSs existing in multiple isoforms in the same organism.
Topics: Glucosyltransferases; Phylogeny; Glucans; Protein Domains; Amino Acid Sequence
PubMed: 38641282
DOI: 10.1016/j.ijbiomac.2024.131680 -
Journal of Molecular Modeling Apr 2024Further understanding of the molecular mechanisms is necessary since it is important for designing new drugs. This study aimed to understand the molecular mechanisms...
CONTEXT
Further understanding of the molecular mechanisms is necessary since it is important for designing new drugs. This study aimed to understand the molecular mechanisms involved in the design of drugs that are inhibitors of the α-glucosidase enzyme. This research aims to gain further understanding of the molecular mechanisms underlying antidiabetic drug design. The molecular docking process yielded 4 compounds with the best affinity energy, including γ-Mangostin, 1,6-dimethyl-ester-3-isomangostin, 1,3,6-trimethyl-ester-α-mangostin, and 3,6,7-trimethyl-ester-γ-mangostin. Free energy calculation with molecular mechanics with generalized born and surface area solvation indicated that the 3,6,7-trimethyl-γ-mangostin had a better free energy value compared to acarbose and simulated maltose together with 3,6,7-trimethyl-γ-mangostin compound. Based on the analysis of electrostatic, van der Waals, and intermolecular hydrogen interactions, 3,6,7-trimethyl-γ-mangostin adopts a noncompetitive inhibition mechanism, whereas acarbose adopts a competitive inhibition mechanism. Consequently, 3,6,7-trimethyl-ester-γ-mangostin, which is a derivative of γ-mangostin, can provide better activity in silico with molecular docking approaches and molecular dynamics simulations.
METHOD
This research commenced with retrieving protein structures from the RCSB database, generating the formation of ligands using the ChemDraw Professional software, conducting molecular docking with the Autodock Vina software, and performing molecular dynamics simulations using the Amber software, along with the evaluation of RMSD values and intermolecular hydrogen bonds. Free energy, electrostatic interactions, and Van der Waals interaction were calculated using MM/GBSA. Acarbose, used as a positive control, and maltose are simulated together with test compound that has the best free energy. The forcefields used for molecular dynamics simulations are ff19SB, gaff2, and tip3p.
Topics: alpha-Glucosidases; Hypoglycemic Agents; Acarbose; Maltose; Molecular Docking Simulation; Molecular Dynamics Simulation; Esters; Xanthones
PubMed: 38634946
DOI: 10.1007/s00894-024-05934-z -
Food Chemistry Aug 2024Street foods are often of poor nutritional quality with high sugar content, in which the overconsumption of sugar is associated with obesity. However, sugar content...
Street foods are often of poor nutritional quality with high sugar content, in which the overconsumption of sugar is associated with obesity. However, sugar content information on local street foods is scarce. Thus, the individual and total sugar contents of 94 types of street foods in Malaysia were analysed. Compared to snacks and main meals, desserts contained the highest amounts of sugar, sucrose, fructose, glucose, and maltose. Sucrose was predominant in 90% desserts, 79.3% snacks, and 68.6% main meals. Most desserts (93.3%) contained medium to high sugar content (≥5 g to >15 g/100 g), while 82.9% main meals and 65.5% snacks had low sugar content. When comparing the sugar contents of 39 foods with other local databases, 58.3% main meals, 55.6% desserts, and 33.3% snacks contained either significantly (p < 0.05) higher or lower sugar contents. Consumers can identify low and high-sugar foods, and policymakers can review health priorities to combat obesity.
Topics: Malaysia; Humans; Snacks; Sugars; Nutritive Value; Food Analysis; Obesity; Dietary Sugars
PubMed: 38631211
DOI: 10.1016/j.foodchem.2024.139288 -
Food Science and Biotechnology Jun 2024This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The...
This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The color parameter results showed that heating time from 1 to 5 h led to brown color, which was consistent with the observed increased in browning intensity. Fourier transform infrared spectroscopy results verified that four carbohydrates reacted with CPP to produce Maillard conjugates. Fluorescence spectroscopy showed that the Maillard reaction changed the tertiary structure of CPP by decreasing the intrinsic fluorescence intensity and surface hydrophobicity compared with the CPP-carbohydrate mixture. At the same time, the Maillard reaction effectively improved the emulsifying properties, reducing power and DPPH radical scavenging activity of CPP. Furthermore, this study also found that glucose and fructose improved CPP more than maltose and dextran. Therefore, monosaccharides have good potential in modifying CPP via the Maillard reaction.
PubMed: 38623432
DOI: 10.1007/s10068-023-01463-2