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1.
Food Res Int ; 183: 114175, 2024 May.
Article in English | MEDLINE | ID: mdl-38760120

ABSTRACT

Lactose hydrolysed concentrated milk was prepared using ß-galactosidase enzyme (4.76U/mL) with a reaction period of 12 h at 4 °C. Addition of polysaccharides (5 % maltodextrin/ß-cyclodextrin) to concentrated milk either before or after lactose hydrolysis did not result in significant differences (p > 0.05) in degree of hydrolysis (% DH) of lactose and residual lactose content (%). Three different inlet temperatures (165 °C, 175 °C and 185 °C) were used for the preparation of powders which were later characterised based on physico-chemical and maillard browning characteristics. Moisture content, solubility and available lysine content of the powders decreased significantly, whereas, browning parameters i.e., browning index, 5-hydroxymethylfurfural, furosine content increased significantly (p < 0.05) with an increase in inlet air temperature. The powder was finally prepared with 5 % polysaccharide and an inlet air temperature of 185 °C which reduced maillard browning. Protein-polysaccharide interactions were identified using Fourier Transform infrared spectroscopy, fluorescence spectroscopy and determination of free amino groups in the powder samples. Maltodextrin and ß-cyclodextrin containing powder samples exhibited lower free amino groups and higher degree of graft value as compared to control sample which indicated protein-polysaccharide interactions. Results obtained from Fourier Transform infrared spectroscopy also confirmed strong protein-polysaccharide interactions, moreover a significant decrease in fluorescence intensity was also observed in the powder samples. These interactions between the proteins and polysaccharides reduced the maillard browning in powders.


Subject(s)
Furaldehyde , Lactose , Maillard Reaction , Milk , Polysaccharides , Powders , Lactose/chemistry , Polysaccharides/chemistry , Milk/chemistry , Animals , Spectroscopy, Fourier Transform Infrared , Furaldehyde/analogs & derivatives , Furaldehyde/chemistry , beta-Galactosidase/metabolism , beta-Cyclodextrins/chemistry , Hydrolysis , Spray Drying , Temperature , Lysine/chemistry , Lysine/analogs & derivatives , Solubility , Spectrometry, Fluorescence , Milk Proteins/chemistry , Food Handling/methods
2.
Appl Microbiol Biotechnol ; 108(1): 338, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38771321

ABSTRACT

Fucosyl-oligosaccharides (FUS) provide many health benefits to breastfed infants, but they are almost completely absent from bovine milk, which is the basis of infant formula. Therefore, there is a growing interest in the development of enzymatic transfucosylation strategies for the production of FUS. In this work, the α-L-fucosidases Fuc2358 and Fuc5372, previously isolated from the intestinal bacterial metagenome of breastfed infants, were used to synthesize fucosyllactose (FL) by transfucosylation reactions using p-nitrophenyl-α-L-fucopyranoside (pNP-Fuc) as donor and lactose as acceptor. Fuc2358 efficiently synthesized the major fucosylated human milk oligosaccharide (HMO) 2'-fucosyllactose (2'FL) with a 35% yield. Fuc2358 also produced the non-HMO FL isomer 3'-fucosyllactose (3'FL) and traces of non-reducing 1-fucosyllactose (1FL). Fuc5372 showed a lower transfucosylation activity compared to Fuc2358, producing several FL isomers, including 2'FL, 3'FL, and 1FL, with a higher proportion of 3'FL. Site-directed mutagenesis using rational design was performed to increase FUS yields in both α-L-fucosidases, based on structural models and sequence identity analysis. Mutants Fuc2358-F184H, Fuc2358-K286R, and Fuc5372-R230K showed a significantly higher ratio between 2'FL yields and hydrolyzed pNP-Fuc than their respective wild-type enzymes after 4 h of transfucosylation. The results with the Fuc2358-F184W and Fuc5372-W151F mutants showed that the residues F184 of Fuc2358 and W151 of Fuc5372 could have an effect on transfucosylation regioselectivity. Interestingly, phenylalanine increases the selectivity for α-1,2 linkages and tryptophan for α-1,3 linkages. These results give insight into the functionality of the active site amino acids in the transfucosylation activity of the GH29 α-L-fucosidases Fuc2358 and Fuc5372. KEY POINTS: Two α-L-fucosidases from infant gut bacterial microbiomes can fucosylate glycans Transfucosylation efficacy improved by tailored point-mutations in the active site F184 of Fuc2358 and W151 of Fuc5372 seem to steer transglycosylation regioselectivity.


Subject(s)
Gastrointestinal Microbiome , Metagenome , Milk, Human , Trisaccharides , alpha-L-Fucosidase , alpha-L-Fucosidase/genetics , alpha-L-Fucosidase/metabolism , Humans , Trisaccharides/metabolism , Milk, Human/chemistry , Lactose/metabolism , Oligosaccharides/metabolism , Mutagenesis, Site-Directed , Infant , Fucose/metabolism
3.
Appl Microbiol Biotechnol ; 108(1): 349, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38809317

ABSTRACT

Galacto-oligosaccharides (GOS) are prebiotic compounds that are mainly used in infant formula to mimic bifidogenic effects of mother's milk. They are synthesized by ß-galactosidase enzymes in a trans-glycosylation reaction with lactose. Many ß-galactosidase enzymes from different sources have been studied, resulting in varying GOS product compositions and yields. The in vivo role of these enzymes is in lactose hydrolysis. Therefore, the best GOS yields were achieved at high lactose concentrations up to 60%wt, which require a relatively high temperature to dissolve. Some thermostable ß-glucosidase enzymes from thermophilic bacteria are also capable of using lactose or para nitrophenyl-galactose as a substrate. Here, we describe the use of the ß-glucosidase BglA from Thermotoga maritima for synthesis of oligosaccharides derived from lactose and cellobiose and their detailed structural characterization. Also, the BglA enzyme kinetics and yields were determined, showing highest productivity at higher lactose and cellobiose concentrations. The BglA trans-glycosylation/hydrolysis ratio was higher with 57%wt lactose than with a nearly saturated cellobiose (20%wt) solution. The yield of GOS was very high, reaching 72.1%wt GOS from lactose. Structural elucidation of the products showed mainly ß(1 → 3) and ß(1 → 6) elongating activity, but also some ß(1 → 4) elongation was observed. The ß-glucosidase BglA from T. maritima was shown to be a very versatile enzyme, producing high yields of oligosaccharides, particularly GOS from lactose. KEY POINTS: • ß-Glucosidase of Thermotoga maritima synthesizes GOS from lactose at very high yield. • Thermotoga maritima ß-glucosidase has high activity and high thermostability. • Thermotoga maritima ß-glucosidase GOS contains mainly (ß1-3) and (ß1-6) linkages.


Subject(s)
Cellobiose , Lactose , Oligosaccharides , Thermotoga maritima , beta-Glucosidase , Thermotoga maritima/enzymology , Thermotoga maritima/genetics , Lactose/metabolism , Cellobiose/metabolism , beta-Glucosidase/metabolism , beta-Glucosidase/genetics , beta-Glucosidase/chemistry , Kinetics , Oligosaccharides/metabolism , Glycosylation , Hydrolysis , Temperature , Enzyme Stability
4.
PLoS One ; 19(5): e0303872, 2024.
Article in English | MEDLINE | ID: mdl-38771780

ABSTRACT

BACKGROUND: Antimicrobial resistance (AMR) is among the top public health concerns in the globe. Estimating the prevalence of multidrug resistance (MDR), MDR index (MDR-I) and extended-spectrum beta-lactamase (ESBL)-producing lactose fermenting Enterobacteriaceae (LFE) is important in designing strategies to combat AMR. Thus, this study was designed to determine the status of MDR, MDR-I and ESBL-producing LFE isolated from the human-dairy interface in the northwestern part of Ethiopia, where such information is lacking. METHODOLOGY: A cross-sectional study was conducted from June 2022 to August 2023 by analyzing 362 samples consisting of raw pooled milk (58), milk container swabs (58), milker's hand swabs (58), farm sewage (57), milker's stool (47), and cow's feces (84). The samples were analyzed using standard bacteriological methods. The antimicrobial susceptibility patterns and ESBL production ability of the LFE isolates were screened using the Kirby-Bauer disk diffusion method, and candidate isolates passing the screening criteria were phenotypically confirmed by using cefotaxime (30 µg) and cefotaxime /clavulanic acid (30 µg/10 µg) combined-disk diffusion test. The isolates were further characterized genotypically using multiplex polymerase chain reaction targeting the three ESBL-encoding- genes namely blaTEM, blaSHV, and blaCTX-M. RESULTS: A total of 375 bacterial isolates were identified and the proportion of MDR and ESBL-producing bacterial isolates were 70.7 and 21.3%, respectively. The MDR-I varied from 0.0 to 0.81 with an average of 0.30. The ESBL production was detected in all sample types. Genotypically, the majority of the isolates (97.5%), which were positive on the phenotypic test, were carrying one or more of the three genes. CONCLUSION: A high proportion of the bacterial isolates were MDR; had high MDR-I and were positive for ESBL production. The findings provide evidence that the human-dairy interface is one of the important reservoirs of AMR traits. Therefore, the implementation of AMR mitigation strategies is highly needed in the area.


Subject(s)
Anti-Bacterial Agents , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae , Lactose , beta-Lactamases , Humans , Ethiopia , beta-Lactamases/genetics , beta-Lactamases/metabolism , Enterobacteriaceae/genetics , Enterobacteriaceae/drug effects , Enterobacteriaceae/isolation & purification , Enterobacteriaceae/enzymology , Lactose/metabolism , Drug Resistance, Multiple, Bacterial/genetics , Cross-Sectional Studies , Anti-Bacterial Agents/pharmacology , Animals , Microbial Sensitivity Tests , Cattle , Enterobacteriaceae Infections/microbiology , Cefotaxime/pharmacology , Milk/microbiology , Fermentation , Feces/microbiology
5.
Int J Pharm ; 657: 124190, 2024 May 25.
Article in English | MEDLINE | ID: mdl-38701910

ABSTRACT

Lubricants are essential for most tablet formulations as they assist powder flow, prevent adhesion to tableting tools and facilitate tablet ejection. Magnesium stearate (MgSt) is an effective lubricant but may compromise tablet strength and disintegratability. In the design of orodispersible tablets, tablet strength and disintegratability are critical attributes of the dosage form. Hence, this study aimed to conduct an in-depth comparative study of MgSt with alternative lubricants, namely sodium lauryl sulphate (SLS), stearic acid (SA) and hydrogenated castor oil (HCO), for their effects on the tableting process as well as tablet properties. Powder blends were prepared with lactose, sodium starch glycolate or crospovidone as the disintegrant, and a lubricant at different concentrations. Angle of repose was determined for the mixtures. Comparative evaluation was carried out based on the ejection force, tensile strength, liquid penetration and disintegratability of the tablets produced. As the lubricant concentration increased, powder flow and tablet ejection improved. The lubrication efficiency generally decreased as follows: MgSt > HCO > SA > SLS. Despite its superior lubrication efficacy, MgSt is the only lubricant of four evaluated that reduced tablet tensile strength. Tablet disintegration time was strongly determined by tensile strength and liquid penetration, which were in turn affected by the lubricant type and concentration. All the above factors should be taken into consideration when deciding the type and concentration of lubricant for an orodispersible tablet formulation.


Subject(s)
Excipients , Lubricants , Stearic Acids , Tablets , Tensile Strength , Lubricants/chemistry , Stearic Acids/chemistry , Excipients/chemistry , Drug Compounding/methods , Powders/chemistry , Sodium Dodecyl Sulfate/chemistry , Castor Oil/chemistry , Povidone/chemistry , Starch/chemistry , Starch/analogs & derivatives , Lactose/chemistry , Administration, Oral , Solubility , Chemistry, Pharmaceutical/methods
6.
Parasit Vectors ; 17(1): 232, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38769548

ABSTRACT

BACKGROUND: Schistosoma japonicum eggs lodge in the liver and induce a fibrotic granulomatous immune response in the liver of host. Galectin 3 (Gal-3) is a protein implicated in fibrosis in multiple organs. However, the pathology and molecular mechanisms promoting hepatic granuloma formation remain poorly understood. METHODS: To investigate the effect of blocking galectin-receptor interactions by α-lactose on liver immunopathology in mice with S. japonicum infection, C57BL/6 mice were infected with S. japonicum and alpha (α)-lactose was intraperitoneally injected to block the interactions of galectins and their receptors. RESULTS: Compared with S. japonicum-infected mice, there were significantly decreased Gal-3 mRNA and protein expression levels, decreased intensity of Gal-3 fluorescence in the liver, decreased serum ALT and AST levels, decreased egg numbers of S. japonicum in the liver section, attenuated hepatic and spleen pathology, and alleviated liver fibrosis accompanied with decreased protein expression levels of fibrosis markers [α-smooth muscle actin (α-SMA), collagen I, and collagen IV] in the liver of S. japonicum-infected mice blocked galectin-receptor interactions with hematoxylin-eosin staining, Masson's trichrome staining, immunohistochemistry, or Western blot analysis. Compared with S. japonicum-infected mice, blocking galectin-receptor interactions led to increased eosinophil infiltration and higher eosinophil cationic protein (ECP) expression in the liver, accompanied by increased mRNA levels of eosinophil granule proteins [ECP and eosinophil peroxidase (EPO)], IL-5, CCL11, and CCR3 in the liver and decreased mRNA levels of Gal-3 and M2 macrophage cytokines (TGF-ß, IL-10, and IL-4) in the liver and spleen by using quantitative real-time reverse transcription-polymerase chain reaction. In addition, there were increased Beclin1 protein expression and protein expression ratio of LC3B-II/LC3B-I and decreased p62 protein expression and protein expression ratios of phospho-mTOR/mTOR and phospho-AKT/AKT by Western blot; increased double-labeled F4/80+/LC3B+ cells by immunofluorescence staining; increased M1 macrophage polarization in the liver of S. japonicum-infected mice blocked galectin-receptor interactions by flow cytometric analysis and immunofluorescence staining. CONCLUSIONS: Our data found that blockage of galectin-receptor interactions downregulated Gal-3, which in turn led to reduced liver functional damage, elevated liver eosinophil recruitment, promoted macrophage autophagy through the Akt/mTOR signaling pathway, and alleviated liver pathology and fibrosis. Therefore, Gal-3 plays a pivotal role during S. japonicum infection and could be a target of pharmacologic potential for liver fibrosis induced by S. japonicum infection.


Subject(s)
Galectin 3 , Liver Cirrhosis , Mice, Inbred C57BL , Schistosoma japonicum , Schistosomiasis japonica , Animals , Schistosomiasis japonica/parasitology , Schistosomiasis japonica/complications , Liver Cirrhosis/parasitology , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Mice , Galectin 3/metabolism , Galectin 3/genetics , Liver/parasitology , Liver/pathology , Liver/metabolism , Female , Lactose/pharmacology , Lactose/analogs & derivatives , Galectins/metabolism , Galectins/genetics
7.
Braz J Microbiol ; 55(2): 1735-1744, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38727922

ABSTRACT

AIMS: To develop and characterize a functional lactose-free ice cream with added ginger and honey, evaluate the survival of Lacticaseibacillus casei CSL3 under frozen storage and the simulated gastrointestinal tract (GIT), as well as antioxidant activity and product acceptability. METHODS AND RESULTS: The survival of Lacticaseibacillus casei CSL3 was evaluated for 180 days, under frozen storage, and GIT at 60 days. At 15 days of storage, proximal composition, antioxidant activity, color, pH, acidity, fusion, density, overrun, and sensory analysis were performed. Ice cream was an effective food matrix for maintaining the viability of CSL3, with concentrations > 7 log CFU g- 1 during storage and GIT. In addition, the analysis showed overrun and prebiotic characteristics through high values of antioxidant activity and phenolic compounds, good acceptability, and purchase intention. CONCLUSIONS: The product has satisfactory market potential (acceptance rate of 95.19% and purchase intention rate > 96%), and it could become another means of inserting probiotics in food.


Subject(s)
Honey , Ice Cream , Lacticaseibacillus casei , Probiotics , Zingiber officinale , Honey/analysis , Zingiber officinale/chemistry , Ice Cream/microbiology , Ice Cream/analysis , Lacticaseibacillus casei/chemistry , Lacticaseibacillus casei/metabolism , Probiotics/chemistry , Humans , Antioxidants/chemistry , Lactose/metabolism , Gastrointestinal Tract/microbiology , Food Storage , Microbial Viability/drug effects
8.
Appl Microbiol Biotechnol ; 108(1): 354, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38819482

ABSTRACT

Whey is a byproduct of dairy industries, the aqueous portion which separates from cheese during the coagulation of milk. It represents approximately 85-95% of milk's volume and retains much of its nutrients, including functional proteins and peptides, lipids, lactose, minerals, and vitamins. Due to its composition, mainly proteins and lactose, it can be considered a raw material for value-added products. Whey-derived products are often used to supplement food, as they have shown several physiological effects on the body. Whey protein hydrolysates are reported to have different activities, including antihypertensive, antioxidant, antithrombotic, opioid, antimicrobial, cytomodulatory, and immuno-modulatory. On the other hand, galactooligosaccharides obtained from lactose can be used as prebiotic for beneficial microorganisms for the human gastrointestinal tract. All these compounds can be obtained through physicochemical, microbial, or enzymatic treatments. Particularly, enzymatic processes have the advantage of being highly selective, more stable than chemical transformations, and less polluting, making that the global enzyme market grow at accelerated rates. The sources and different products associated with the most used enzymes are particularly highlighted in this review. Moreover, we discuss metagenomics as a tool to identify novel proteolytic enzymes, from both cultivable and uncultivable microorganisms, which are expected to have new interesting activities. Finally enzymes for the transformation of whey sugar are reviewed. In this sense, carbozymes with ß-galactosidase activity are capable of lactose hydrolysis, to obtain free monomers, and transgalactosylation for prebiotics production. KEY POINTS: • Whey can be used to obtain value-added products efficiently through enzymatic treatments • Proteases transform whey proteins into biopeptides with physiological activities • Lactose can be transformed into prebiotic compounds using ß-galactosidases.


Subject(s)
Protein Hydrolysates , Whey Proteins , Whey Proteins/metabolism , Protein Hydrolysates/metabolism , Protein Hydrolysates/chemistry , Prebiotics , Humans , Whey/chemistry , Whey/metabolism , Lactose/metabolism , beta-Galactosidase/metabolism , beta-Galactosidase/genetics
9.
Bioorg Chem ; 147: 107395, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38705105

ABSTRACT

Fluorination of carbohydrate ligands of lectins is a useful approach to examine their binding profile, improve their metabolic stability and lipophilicity, and convert them into 19F NMR-active probes. However, monofluorination of monovalent carbohydrate ligands often leads to a decreased or completely lost affinity. By chemical glycosylation, we synthesized the full series of methyl ß-glycosides of N,N'-diacetylchitobiose (GlcNAcß(1-4)GlcNAcß1-OMe) and LacdiNAc (GalNAcß(1-4)GlcNAcß1-OMe) systematically monofluorinated at all hydroxyl positions. A competitive enzyme-linked lectin assay revealed that the fluorination at the 6'-position of chitobioside resulted in an unprecedented increase in affinity to wheat germ agglutinin (WGA) by one order of magnitude. For the first time, we have characterized the binding profile of a previously underexplored WGA ligand LacdiNAc. Surprisingly, 4'-fluoro-LacdiNAc bound WGA even stronger than unmodified LacdiNAc. These observations were interpreted using molecular dynamic calculations along with STD and transferred NOESY NMR techniques, which gave evidence for the strengthening of CH/π interactions after deoxyfluorination of the side chain of the non-reducing GlcNAc. These results highlight the potential of fluorinated glycomimetics as high-affinity ligands of lectins and 19F NMR-active probes.


Subject(s)
Disaccharides , Wheat Germ Agglutinins , Disaccharides/chemistry , Disaccharides/chemical synthesis , Wheat Germ Agglutinins/chemistry , Wheat Germ Agglutinins/metabolism , Halogenation , Molecular Structure , Acetylglucosamine/chemistry , Acetylglucosamine/metabolism , Lactose/analogs & derivatives
10.
Cryo Letters ; 45(2): 134-138, 2024.
Article in English | MEDLINE | ID: mdl-38557992

ABSTRACT

BACKGROUND: Examining semen cryopreservation in Calomys laucha offers valuable insights for reproductive research and species conservation. OBJECTIVE: To determine the most effective sugar for the cryopreservation of C. laucha semen. MATERIALS AND METHODS: Using 36 epididymides from C. laucha, semen samples were diluted in a 3% skimmed milk medium supplemented with one of four sugars (glucose, fructose, lactose, or sucrose) at a concentration of 0.3 M. These mixtures underwent a conditioning phase at 37 degree C for 10 min, cooled to -80 degree C for another 10 min, and were subsequently stored in liquid nitrogen. RESULTS: Upon thawing, samples treated with lactose and glucose solutions show superior sperm motility, achieving 8.2% and 10.0% respectively, in contrast to the fructose (2.0%) and sucrose (4.1%) mixtures. Furthermore, samples preserved in glucose registered the highest sperm penetration rates, reaching 44.9%. CONCLUSION: Our findings suggest that a cryopreservation medium containing 0.3 M glucose can contribute to the safeguarding C. laucha rodent semen. https://doi.org/10.54680/fr24210110612.


Subject(s)
Semen Preservation , Semen , Animals , Male , Cryopreservation , Lactose , Rodentia , Sperm Motility , Glucose/pharmacology , Fructose , Sucrose/pharmacology , Spermatozoa , Cryoprotective Agents
11.
Microb Cell Fact ; 23(1): 112, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38622596

ABSTRACT

BACKGROUND: Filamentous fungi have long been recognized for their exceptional enzyme production capabilities. Among these, Trichoderma reesei has emerged as a key producer of various industrially relevant enzymes and is particularly known for the production of cellulases. Despite the availability of advanced gene editing techniques for T. reesei, the cultivation and characterization of resulting strain libraries remain challenging, necessitating well-defined and controlled conditions with higher throughput. Small-scale cultivation devices are popular for screening bacterial strain libraries. However, their current use for filamentous fungi is limited due to their complex morphology. RESULTS: This study addresses this research gap through the development of a batch cultivation protocol using a microbioreactor for cellulase-producing T. reesei strains (wild type, RutC30 and RutC30 TR3158) with offline cellulase activity analysis. Additionally, the feasibility of a microscale fed-batch cultivation workflow is explored, crucial for mimicking industrial cellulase production conditions. A batch cultivation protocol was developed and validated using the BioLector microbioreactor, a Round Well Plate, adapted medium and a shaking frequency of 1000 rpm. A strong correlation between scattered light intensity and cell dry weight underscores the reliability of this method in reflecting fungal biomass formation, even in the context of complex fungal morphology. Building on the batch results, a fed-batch strategy was established for T. reesei RutC30. Starting with a glucose concentration of 2.5 g l - 1 in the batch phase, we introduced a dual-purpose lactose feed to induce cellulase production and prevent carbon catabolite repression. Investigating lactose feeding rates from 0.3 to 0.75 g (l h) - 1 , the lowest rate of 0.3 g (l h) - 1 revealed a threefold increase in cellobiohydrolase and a fivefold increase in ß -glucosidase activity compared to batch processes using the same type and amount of carbon sources. CONCLUSION: We successfully established a robust microbioreactor batch cultivation protocol for T. reesei wild type, RutC30 and RutC30 TR3158, overcoming challenges associated with complex fungal morphologies. The study highlights the effectiveness of microbioreactor workflows in optimizing cellulase production with T. reesei, providing a valuable tool for simultaneous assessment of critical bioprocess parameters and facilitating efficient strain screening. The findings underscore the potential of microscale fed-batch strategies for enhancing enzyme production capabilities, revealing insights for future industrial applications in biotechnology.


Subject(s)
Cellulase , Hypocreales , Trichoderma , Cellulase/metabolism , Lactose/metabolism , Reproducibility of Results , Biotechnology , Trichoderma/metabolism
12.
Food Microbiol ; 121: 104487, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38637064

ABSTRACT

Streptococcus thermophilus is a bacterium widely used in the production of yogurts and cheeses, where it efficiently ferments lactose, the saccharide naturally present in milk. It is also employed as a starter in dairy- or plant-based fermented foods that contain saccharides other than lactose (e.g., sucrose, glucose). However, little is known about how saccharide use is regulated, in particular when saccharides are mixed. Here, we determine the effect of the 5 sugars that S. thermophilus is able to use, at different concentration and when they are mixed on the promoter activities of the C-metabolism genes. Using a transcriptional fusion approach, we discovered that lactose and glucose modulated the activity of the lacS and scrA promoters in a concentration-dependent manner. When mixed with lactose, glucose also repressed the two promoter activities; when mixed with sucrose, lactose still repressed scrA promoter activity. We determined that catabolite control protein A (CcpA) played a key role in these dynamics. We also showed that promoter activity was linked with glycolytic flux, which varied depending on saccharide type and concentration. Overall, this study identified key mechanisms in carbohydrate metabolism - autoregulation and partial hierarchical control - and demonstrated that they are partly mediated by CcpA.


Subject(s)
Glucose , Lactose , Lactose/metabolism , Glucose/metabolism , Carbohydrate Metabolism , Glycolysis , Streptococcus thermophilus/genetics , Streptococcus thermophilus/metabolism , Sucrose/metabolism
13.
Sci Rep ; 14(1): 7852, 2024 04 03.
Article in English | MEDLINE | ID: mdl-38570624

ABSTRACT

CsqR (YihW) is a local transcription factor that controls expression of yih genes involved in degradation of sulfoquinovose in Escherichia coli. We recently showed that expression of the respective gene cassette might be regulated by lactose. Here, we explore the phylogenetic and functional traits of CsqR. Phylogenetic analysis revealed that CsqR had a conserved Met25. Western blot demonstrated that CsqR was synthesized in the bacterial cell as two protein forms, 28.5 (CsqR-l) and 26 kDa (CsqR-s), the latter corresponding to start of translation at Met25. CsqR-s was dramatically activated during growth with sulfoquinovose as a sole carbon source, and displaced CsqR-l in the stationary phase during growth on rich medium. Molecular dynamic simulations revealed two possible states of the CsqR-s structure, with the interdomain linker being represented by either a disordered loop or an ɑ-helix. This helix allowed the hinge-like motion of the N-terminal domain resulting in a switch of CsqR-s between two conformational states, "open" and "compact". We then modeled the interaction of both CsqR forms with putative effectors sulfoquinovose, sulforhamnose, sulfoquinovosyl glycerol, and lactose, and revealed that they all preferred the same pocket in CsqR-l, while in CsqR-s there were two possible options dependent on the linker structure.


Subject(s)
Escherichia coli Proteins , Escherichia coli , Escherichia coli/genetics , Escherichia coli/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Phylogeny , Lactose/metabolism , Escherichia coli Proteins/metabolism
14.
Int J Pharm ; 656: 124116, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38615803

ABSTRACT

Inhalation of pharmaceutical aerosol formulations is widely used to treat respiratory diseases. Spatially resolved thermal characterization offers promise for better understanding drug release rates from particles; however, this has been an analytical challenge due to the small particle size (from a few micrometers down to nanometers) and the complex composition of the formulations. Here, we employ nano-thermal analysis (nanoTA) to probe the nanothermal domain of a pharmaceutical aerosol formulation containing a mixture of fluticasone propionate (FP), salmeterol xinafoate (SX), and excipient lactose, which is widely used to treat asthma and chronic obstructive pulmonary disease (COPD). Furthermore, atomic force microscopy-infrared spectroscopy (AFM-IR) and AFM force measurements are performed to provide nanochemical and nanomechanical information to complement the nanothermal data. The colocalized thermal and chemical mapping clearly reveals the surface heterogeneity of the drugs in the aerosol particles and demonstrates the contribution of the surface chemical composition to the variation in the thermal properties of the particles. We present a powerful analytical approach for in-depth characterization of thermal/chemical/morphological properties of dry powder inhaler particles at micro- and nanometer scales. This approach can be used to facilitate the comparison between generics and reference inhalation products and further the development of high-performance pharmaceutical formulations.


Subject(s)
Aerosols , Dry Powder Inhalers , Fluticasone , Lactose , Microscopy, Atomic Force , Particle Size , Powders , Salmeterol Xinafoate , Fluticasone/chemistry , Fluticasone/administration & dosage , Salmeterol Xinafoate/chemistry , Salmeterol Xinafoate/administration & dosage , Lactose/chemistry , Microscopy, Atomic Force/methods , Excipients/chemistry , Administration, Inhalation , Bronchodilator Agents/administration & dosage , Bronchodilator Agents/chemistry , Spectrophotometry, Infrared/methods , Chemistry, Pharmaceutical/methods , Surface Properties
15.
Biomater Adv ; 160: 213849, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38599041

ABSTRACT

Spheroids derived from human mesenchymal stem cells (hMSCs) are of limited use for cartilage regeneration, as the viability of the cells progressively decreases during the period required for chondrogenic differentiation (21 days). In this work, spheroids based on hMSCs and a lactose-modified chitosan (CTL) were formed by seeding cells onto an air-dried coating of CTL. The polymer coating can inhibit cell adhesion and it is simultaneously incorporated into spheroid structure. CTL-spheroids were characterized from a morphological and biological perspective, and their properties were compared with those of spheroids obtained by seeding the cells onto a non-adherent surface (agar gel). Compared to the latter, smaller and more viable spheroids form in the presence of CTL as early as 4 days of culture. At this time point, analysis of stem cells differentiation in spheroids showed a remarkable increase in collagen type-2 (COL2A1) gene expression (~700-fold compared to day 0), whereas only a 2-fold increase was observed in the control spheroids at day 21. These results were confirmed by histological and transmission electron microscopy (TEM) analyses, which showed that in CTL-spheroids an early deposition of collagen with a banding structure already occurred at day 7. Overall, these results support the use of CTL-spheroids as a novel system for cartilage regeneration, characterized by increased cell viability and differentiation capacity within a short time-frame. This will pave the way for approaches aimed at increasing the success rate of procedures and reducing the time required for tissue regeneration.


Subject(s)
Cell Differentiation , Chitosan , Chondrogenesis , Lactose , Mesenchymal Stem Cells , Spheroids, Cellular , Chitosan/pharmacology , Chitosan/chemistry , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/cytology , Humans , Cell Differentiation/drug effects , Chondrogenesis/drug effects , Spheroids, Cellular/drug effects , Spheroids, Cellular/cytology , Lactose/pharmacology , Lactose/chemistry , Cell Survival/drug effects , Cells, Cultured , Collagen Type II/metabolism , Collagen Type II/genetics
16.
Front Endocrinol (Lausanne) ; 15: 1386510, 2024.
Article in English | MEDLINE | ID: mdl-38665263

ABSTRACT

In hypothyroid patients needing large doses of levothyroxine (L-T4) (>1.7-2 µg/kg/day) to reach euthyroidism, lactose intolerance (LI) needs to be excluded, owing to the high prevalence in the population. If LI is present, a lactose-free diet decreases the rate of L-T4 malabsorption. However, an increased requirement of L-T4 is described in patients with LI, which can be beneficially treated using lactose-free L-T4 formulation. The lactose-free liquid L-T4 formulation is able to circumvent LI malabsorption leading to the normalization of thyroid-stimulating hormone (TSH) in patients with subclinical hypothyroidism and long-term stable TSH levels.


Subject(s)
Hypothyroidism , Lactose Intolerance , Thyroxine , Humans , Lactose Intolerance/drug therapy , Thyroxine/therapeutic use , Thyroxine/pharmacokinetics , Hypothyroidism/drug therapy , Hypothyroidism/metabolism , Lactose , Female , Malabsorption Syndromes/drug therapy , Malabsorption Syndromes/metabolism , Male , Middle Aged , Thyrotropin/blood , Thyrotropin/metabolism , Adult
17.
Int J Pharm ; 658: 124150, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38663645

ABSTRACT

This study investigates decompression and ejection conditions on tablet characteristics by comparing compact densities and tensile strengths made using regular rigid dies and custom-built die systems that enable triaxial decompression. Die-wall pressure evolution during decompression and ejection stresses did not meaningfully impact the density and tensile strength of the materials tested: microcrystalline cellulose, crystalline lactose monohydrate, and mannitol. Furthermore, the apparent differences in tensile strength between rectangular cuboids and cylindrical compacts are unrelated to decompression and ejection conditions, but rather a consequence of their shapes and of the test configurations. This suggests that elastic and plastic deformations that may occur during decompression and ejection are not significantly influenced by die-wall pressure evolution. We thus conclude that while triaxial decompression and constraint-free ejection may allow the production of defect-free compacts for materials that otherwise are defect prone using a rigid die, they seem to pose no benefits when the materials already produce defect-free compacts using a rigid die.


Subject(s)
Cellulose , Excipients , Lactose , Mannitol , Tablets , Tensile Strength , Cellulose/chemistry , Lactose/chemistry , Mannitol/chemistry , Excipients/chemistry , Technology, Pharmaceutical/methods , Pressure , Drug Compounding/methods , Chemistry, Pharmaceutical/methods
18.
Bioprocess Biosyst Eng ; 47(6): 919-929, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38644439

ABSTRACT

The growing need in the current market for innovative solutions to obtain lactose-free (L-F) milk is caused by the annual increase in the prevalence of lactose intolerance inside as well as the newborn, children, and adults. Various configurations of enzymes can yield two distinct L-F products: sweet (ß-galactosidase) and unsweet (ß-galactosidase and glucose oxidase) L-F milk. In addition, the reduction of sweetness through glucose decomposition should be performed in a one-pot mode with catalase to eliminate product inhibition caused by H2O2. Both L-F products enjoy popularity among a rapidly expanding group of consumers. Although enzyme immobilization techniques are well known in industrial processes, new carriers and economic strategies are still being searched. Polymeric carriers, due to the variety of functional groups and non-toxicity, are attractive propositions for individual and co-immobilization of food enzymes. In the presented work, two strategies (with free and immobilized enzymes; ß-galactosidase NOLA, glucose oxidase from Aspergillus niger, and catalase from Serratia sp.) for obtaining sweet and unsweet L-F milk under low-temperature conditions were proposed. For free enzymes, achieving the critical assumption, lactose hydrolysis and glucose decomposition occurred after 1 and 4.3 h, respectively. The tested catalytic membranes were created on regenerated cellulose and polyamide. In both cases, the time required for lactose and glucose bioconversion was extended compared to free enzymes. However, these preparations could be reused for up to five (ß-galactosidase) and ten cycles (glucose oxidase with catalase).


Subject(s)
Enzymes, Immobilized , Glucose Oxidase , Lactose , Milk , beta-Galactosidase , beta-Galactosidase/metabolism , beta-Galactosidase/chemistry , Milk/chemistry , Lactose/metabolism , Lactose/chemistry , Glucose Oxidase/chemistry , Glucose Oxidase/metabolism , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Animals , Aspergillus niger/enzymology , Glucose/metabolism , Glucose/chemistry , Catalase/metabolism , Catalase/chemistry , Membranes, Artificial
19.
Int J Pharm ; 657: 124122, 2024 May 25.
Article in English | MEDLINE | ID: mdl-38621619

ABSTRACT

The aim of this study was to investigate how the propensity for aerosolisation in binary adhesive mixtures was affected by the drug load, and to determine whether these findings could be linked to different blend states. Binary blends of two different lactose carriers, each with varying size and morphology, were prepared together with budesonide. In vitro aerosolisation studies were conducted at four different pressure drops, ranging from 0.5 to 4 kPa, utilising a Next Generation Impactor. Several dispersion parameters were derived from the relationship between the quantity of dispersed API and the pressure drop. The evolution of the parameters with drug load was complex, especially at low drug loads. While similar responses were observed for both carriers, the range of drug load that could be used varied significantly. The choice of carrier not only influenced the capacity for drug loading but also affected the spatial distribution of the API within the mixture, which, in turn, affected its aerosolisation propensity. Thus, the drug dispersion process could be linked to different configurations of the lactose carrier and budesonide in the blends, i.e. blend states. In conclusion, the study suggests that the concept of blend states can provide an explanation for the complex dispersion process observed in adhesive blends.


Subject(s)
Adhesives , Aerosols , Budesonide , Drug Carriers , Lactose , Budesonide/chemistry , Budesonide/administration & dosage , Lactose/chemistry , Administration, Inhalation , Adhesives/chemistry , Drug Carriers/chemistry , Particle Size , Chemistry, Pharmaceutical/methods
20.
Arch Pharm Res ; 47(4): 325-340, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38561494

ABSTRACT

Sialyllactoses (SLs) primarily include sialylated human milk oligosaccharides (HMOs) and bovine milk oligosaccharides (BMOs). First, the safety assessment of 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL) revealed low toxicity in various animal models and human participants. SLs constitute a unique milk component, highlighting the essential nutrients and bioactive components crucial for infant development, along with numerous associated health benefits for various diseases. This review explores the safety, biosynthesis, and potential biological effects of SLs, with a specific focus on their influence across various physiological systems, including the gastrointestinal system, immune disorders, rare genetic disorders (such as GNE myopathy), cancers, neurological disorders, cardiovascular diseases, diverse cancers, and viral infections, thus indicating their therapeutic potential.


Subject(s)
Lactose/analogs & derivatives , Milk, Human , Milk , Oligosaccharides , Humans , Oligosaccharides/chemistry , Oligosaccharides/metabolism , Animals , Milk/chemistry , Milk, Human/chemistry , Milk, Human/metabolism , Cattle
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