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Chemical & Pharmaceutical Bulletin 2022Exopolysaccharides (EPSs) occur widely in natural products made by bacteria, fungi and algae. Some EPSs have intriguing biological properties such as anticancer and...
Exopolysaccharides (EPSs) occur widely in natural products made by bacteria, fungi and algae. Some EPSs have intriguing biological properties such as anticancer and immunomodulatory activities. Our group has recently found that EPSs generated from Leuconostoc mesenteroides ssp. mesenteroides strain NTM048 (NTM048 EPS) enhanced a production of mucosal immunoglobulin A (IgA) of mouse. Herein, we described the synthesis and evaluation of the tetrasaccharide fragments of NTM048 EPS to obtain information about the molecular mechanism responsible for the IgA-inducing activity.
Topics: Biological Products; Carbohydrate Conformation; Leuconostoc; Polysaccharides
PubMed: 35110436
DOI: 10.1248/cpb.c21-00919 -
Journal of Microbiology and... Nov 2021The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic (ETEC) during the...
The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25°C, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera , and were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic (ETEC).
Topics: Brassica; Enterotoxigenic Escherichia coli; Fermentation; Fermented Foods; Food Microbiology; High-Throughput Nucleotide Sequencing; Hydrogen-Ion Concentration; Lactobacillus; Leuconostoc; Microbiota; RNA, Ribosomal, 16S; Temperature; Weissella
PubMed: 34489379
DOI: 10.4014/jmb.2108.08038 -
Journal of Applied Microbiology 2004To develop a multiplex PCR approach for simultaneous detection of Leuconostoc and Carnobacterium and its validation in meat products.
AIMS
To develop a multiplex PCR approach for simultaneous detection of Leuconostoc and Carnobacterium and its validation in meat products.
METHODS AND RESULTS
Two multiplex PCR assays were developed using newly designed 16S rDNA-directed primers adapted to the current taxonomic situation of genera Leuconostoc and Carnobacterium that allow: (i) simultaneous detection of both genera, and members of the nonmotile species of genus Carnobacterium and (ii) identification in a single assay of the nonmotile species C. divergens, C. maltaromicum and C. gallinarum. Sensitivity values of 10(3) and 10(4) CFU g(-1) were determined for multiplex PCR detection of Carnobacterium and Leuconostoc, respectively, following artificially inoculated meat trials. In addition, both multiplex PCR assays were validated in 14 naturally contaminated samples covering nine types of meat products. Results obtained by colony identification were confirmed by PCR detection.
CONCLUSIONS
The methods described in this study provide a rapid and reliable tool for PCR detection of Carnobacterium and Leuconostoc, in meat products, and for colony identification.
SIGNIFICANCE AND IMPACT OF THE STUDY
This multiplex PCR approach will help in the analysis of the spoilage microbiota of refrigerated vacuum-packaged meat product in order to determine the appropriate preservation method.
Topics: Animals; Base Sequence; Chickens; DNA Primers; DNA, Bacterial; Lactobacillaceae; Leuconostoc; Meat Products; Polymerase Chain Reaction; Reproducibility of Results; Sequence Alignment; Swine; Turkeys
PubMed: 15239706
DOI: 10.1111/j.1365-2672.2004.02317.x -
BioMed Research International 2022This study included the role of subsp. cremoris in oral diseases such as periodontitis. . Isolation and identification of subsp. cremoris from a saliva sample of...
This study included the role of subsp. cremoris in oral diseases such as periodontitis. . Isolation and identification of subsp. cremoris from a saliva sample of twenty patients wearing fixed dental prostheses suffering from periodontitis followed by estimating susceptibility generally to the most common antibiotics and specifically to chlorhexidine (CHX) to determine the MIC of CHX and also screening of the strength of biofilm production under aerobic and anaerobic conditions; here, the study included six groups: Group I: screening of biofilm formation under aerobic condition, Group II: screening the MIC of CHX effect on biofilm formation under aerobic condition, Group III: screening of the MIC of CHX effect on preformed biofilm under aerobic condition, Group IV: screening of biofilm formation under anaerobic condition, Group V: screening of MIC of CHX effect on biofilm formation under anaerobic condition, and Group VI: screening of MIC of CHX effect on preformed biofilm under anaerobic condition. . The results showed that about 5 (25%) isolates were identified as subsp. cremoris, while 75% are other isolates. Furthermore, susceptibility results to antibiotic showed the sensitivity to penicillin (100%), azithromycin (100%), ciprofloxacin (100%), tetracycline (100%), gentamicin (100%), doxycycline (100%), vancomycin (100%), ofloxacin (60%), chloramphenicol (80%), ampicillin (80%), and cefoxitin (60%). On the other side, the biofilm production assays revealed that all isolates were moderate biofilm former under the aerobic and anaerobic conditions but for the biofilm treated with MIC of CHX, the current study noticed that the strength of the biofilm became weaker in aerobic and anaerobic conditions; regardless, the strength of the biofilm under anaerobic conditions was higher than in that under aerobic conditions, with no significant differences at ≤ 0.05 depending on the statistical analysis (-test) before and after the treatment with MIC of CHX in aerobic and anaerobic conditions. . The presence of subsp. cremoris in the oral cavity is due to eating foods and vegetables; based on the strength of the biofilm and sensitivity tests, the isolates have less pathogenicity in the oral cavity due to the weakness of the biofilm production and the lack of resistance to antibiotics.
Topics: Anti-Bacterial Agents; Humans; Leuconostoc; Periodontitis; Prostheses and Implants
PubMed: 35647195
DOI: 10.1155/2022/8790096 -
Food Microbiology Oct 2023Leuconostoc spp. is often regarded as the flavor producer, responsible for the production of acetoin and diacetyl in dairy cheese. In this study, we investigate seven...
Leuconostoc spp. is often regarded as the flavor producer, responsible for the production of acetoin and diacetyl in dairy cheese. In this study, we investigate seven plant-derived Leuconostoc strains, covering four species, in their potential as a lyophilized starter culture for flavor production in fermented soy-based cheese alternatives. We show that the process of lyophilization of Leuconostoc can be feasible using a soy-based lyoprotectant, with survivability up to 63% during long term storage. Furthermore, the storage in this media improves the subsequent growth in a soy-based substrate in a strain specific manner. The utilization of individual raffinose family oligosaccharides was strain dependent, with Leuconostoc pseudomesenteroides NFICC99 being the best consumer. Furthermore, we show that all investigated strains were able to produce a range of volatile flavor compounds found in dairy cheese products, as well as remove certain dairy off-flavors from the soy-based substrate like hexanal and 2-pentylfuran. Also here, NFICC99 was strain producing most cheese-related volatile flavor compounds, followed by Leuconostoc mesenteroides NFICC319. These findings provide initial insights into the development of Leuconostoc as a potential starter culture for plant-based dairy alternatives, as well as a promising approach for generation of stable, lyophilized cultures.
Topics: Fermentation; Leuconostoc; Dairy Products; Hydrogen-Ion Concentration; Sugars
PubMed: 37567639
DOI: 10.1016/j.fm.2023.104337 -
Journal of Food Protection Jun 2020The presence of lactic acid bacteria can be detrimental when the abundant growth of slime-producing strains (Lactobacillus spp. and Leuconostoc spp.) causes spoilage of...
ABSTRACT
The presence of lactic acid bacteria can be detrimental when the abundant growth of slime-producing strains (Lactobacillus spp. and Leuconostoc spp.) causes spoilage of meat products. Two strains of lactic acid bacteria were isolated from vacuum-packed cooked hams that had been withdrawn from the market for the so-called ropy slime defect and identified as Leuconostoc mesenteroides. In an attempt to define the behavior of ropy slime-producing bacteria, two strains of L. mesenteroides were incubated in de Man Rogosa Sharpe broth at different storage temperatures and conditions of thermal abuse (4, 12, 20, 30, 37, and 44°C). Both strains showed a lack of growth at 44°C, a good level of development at 30 and 37°C, and evident growth ability at low temperatures, with a long stationary phase. In particular, the bacterial concentration at 4°C was >105 CFU mL-1 after more than 120 days of incubation. This study demonstrates that the refrigeration temperature for cooked meat products does not constitute a hurdle for ropy slime producers and their subsequent ability to spoil.
Topics: Food Microbiology; Food Packaging; Humans; Lactobacillus; Leuconostoc; Leuconostoc mesenteroides; Meat; Meat Products; Temperature
PubMed: 31930931
DOI: 10.4315/JFP-19-521 -
PloS One 2013We used combinatorial engineering to investigate the relationships between structure and linkage specificity of the dextransucrase DSR-S from Leuconostoc mesenteroides...
We used combinatorial engineering to investigate the relationships between structure and linkage specificity of the dextransucrase DSR-S from Leuconostoc mesenteroides NRRL B-512F, and to generate variants with altered specificity. Sequence and structural analysis of glycoside-hydrolase family 70 enzymes led to eight amino acids (D306, F353, N404, W440, D460, H463, T464 and S512) being targeted, randomized by saturation mutagenesis and simultaneously recombined. Screening of two libraries totaling 3.6.10(4) clones allowed the isolation of a toolbox comprising 81 variants which synthesize high molecular weight α-glucans with different proportions of α(1→3) linkages ranging from 3 to 20 %. Mutant sequence analysis, biochemical characterization and molecular modelling studies revealed the previously unknown role of peptide (460)DYVHT(464) in DSR-S linkage specificity. This peptide sequence together with residue S512 contribute to defining +2 subsite topology, which may be critical for the enzyme regiospecificity.
Topics: Amino Acid Sequence; Catalysis; Dextrans; Glucans; Glucosyltransferases; Glycosyltransferases; Leuconostoc; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Sequence Data; Mutagenesis, Site-Directed; Mutation; Peptide Fragments; Peptide Library; Protein Engineering; Sequence Homology, Amino Acid; Structure-Activity Relationship; Substrate Specificity
PubMed: 24204991
DOI: 10.1371/journal.pone.0077837 -
Microbiology (Reading, England) Feb 2010Pulsed-field gel electrophoresis analysis of chromosomal single and double restriction profiles of 17 strains belonging to three genera of 'Leuconostocaceae' was done,...
Pulsed-field gel electrophoresis analysis of chromosomal single and double restriction profiles of 17 strains belonging to three genera of 'Leuconostocaceae' was done, resulting in physical and genetic maps for three Fructobacillus, six Leuconostoc and four Weissella strains. AscI, I-CeuI, NotI and SfiI restriction enzymes were used together with Southern hybridization of selected probes to provide an assessment of genomic organization in different species. Estimated genome sizes varied from 1408 kb to 1547 kb in Fructobacillus, from 1644 kb to 2133 kb in Leuconostoc and from 1371 kb to 2197 kb in Weissella. Other genomic characteristics of interest were analysed, such as oriC and terC localization and rrn operon organization. The latter seems markedly different in Weissella, in both number and disposition in the chromosome. Comparisons of intra- and intergeneric features are discussed in the light of chromosome rearrangements and genomic evolution.
Topics: Chromosome Mapping; Chromosomes, Bacterial; DNA Restriction Enzymes; Electrophoresis, Gel, Pulsed-Field; Genetic Variation; Genome, Bacterial; Gram-Positive Bacteria; Leuconostoc; Leuconostocaceae; Physical Chromosome Mapping; Species Specificity
PubMed: 19892761
DOI: 10.1099/mic.0.028308-0 -
The ISME Journal Nov 2013Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was...
Maintenance of a high degree of biodiversity in homogeneous environments is poorly understood. A complex cheese starter culture with a long history of use was characterized as a model system to study simple microbial communities. Eight distinct genetic lineages were identified, encompassing two species: Lactococcus lactis and Leuconostoc mesenteroides. The genetic lineages were found to be collections of strains with variable plasmid content and phage sensitivities. Kill-the-winner hypothesis explaining the suppression of the fittest strains by density-dependent phage predation was operational at the strain level. This prevents the eradication of entire genetic lineages from the community during propagation regimes (back-slopping), stabilizing the genetic heterogeneity in the starter culture against environmental uncertainty.
Topics: Bacteriophages; Cheese; Food Microbiology; Genetic Variation; Genome, Bacterial; Lactococcus lactis; Leuconostoc; Plasmids; RNA, Ribosomal, 16S
PubMed: 23823494
DOI: 10.1038/ismej.2013.108 -
Journal of Dairy Science Feb 2022Exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) is a linear dextran that is built by glucose units via α-1,6 glycosidic bond. The primary objective...
Exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) is a linear dextran that is built by glucose units via α-1,6 glycosidic bond. The primary objective of this study was to investigate the yield of XG5 EPS and its application in set yogurt. In laboratory scale, the culture conditions of XG5 EPS production were optimized using the L9 (3) orthogonal test. Here, the optimized yield of XG5 EPS was 26.02 g/L under the conditions of 100 g/L sucrose, initial pH 7.0, 25°C incubation, and 100 rpm for 36 h in a shaking flask. Based on the optimized parameters of laboratory scale, a pilot fed-batch fermentation was performed in a 50-L bioreactor with an adjusted agitation speed of 20 rpm. The XG5 EPS yield reached 40.07 g/L in fed-batch fermentation, which was 54% higher than that achieved in laboratory scale. In addition, XG5 EPS was added into set yogurt to investigate its effect on the stability of set yogurt. Our data demonstrated that the XG5 EPS improved the water-holding capacity, texture profile, and viscosity of set yogurt during cold storage compared with the controls. In particular, addition of 0.5% XG5 EPS increased the structure of 3-dimensional network of set yogurt, which eventually improved the physical stability of the set yogurt. Overall, this study provided new insights for exploring the pilot scale production and application of dextran.
Topics: Animals; Fermentation; Leuconostoc; Polysaccharides, Bacterial; Yogurt
PubMed: 34998545
DOI: 10.3168/jds.2021-20997