scholarly journals Characterization of enterocins produced by Enterococcus mundtii isolated from humans feces

2007 ◽  
Vol 50 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Alessandra Einsfeld Ferreira ◽  
Natália Canal ◽  
Daiana Morales ◽  
Daiane Bopp Fuentefria ◽  
Gertrudes Corção
Keyword(s):  
Molecular Weight ◽  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Storage Test ◽  
Logarithmic Growth Phase ◽  
Primary Metabolite ◽  
Enterococcus Mundtii ◽  
Kinetics Of ◽  
Logarithmic Growth

The aim of this study was to characterize bacteriocins produced by 70 strains of Enterococcus mundtii.Four strains exhibited antibiotic activity towards Listeria innocua, L. monocytogenes, Lactobacillus plantarum, and Salmonella Enteritidis. They remained active under temperatures of up to 121ºC for 20 min, and under pH treatments that varied from 2.0 to 10.0. Antimicrobial activity was maintained during the storage test for 60 days under freezing. The kinetics of production revealed the peak activity of 1600 AU /mL during the logarithmic growth phase and the molecular weight found was approximately 3.0 kDa. The characterization of the products with antimicrobial activity indicated their proteic nature, presenting a typical kinetics of primary metabolite and a molecular weight similar to many purified enterocins.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

scholarly journals Antimicrobial activity and chemical characterization of the bark decoction of cumaru stem

2020 ◽  
Vol 50 (3) ◽  
Author(s):  
Maria Jaiana Gomes Ferreira ◽  
Patrícia Coelho do Nascimento Nogueira ◽  
Flayanna Gouveia Braga Dias ◽  
Larissa Morais Ribeiro da Silva ◽  
Edilberto Rocha Silveira ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Enteritidis ◽  
Chemical Characterization ◽  
Chemical Compounds ◽  
Stem Bark ◽  
Liquid Chromatography Mass Spectrometry ◽  
1H And 13C Nmr ◽  
Gram Positive Bacteria

ABSTRACT: The plant, Amburana cearensis A. C. Smith (Fabaceae), commonly called cumaru, is widespread in the Caatinga cearense, a less known ecosystem in Brazil. A. cearensis is rich in several compounds like protocatechuic acid, tannins, coumarin, flavonoids and phenolic heterosides, such as amburosides A and B, that have been isolated. The aim of this study was to determine the antimicrobial potential and draw the chemical profile of the distinct characteristics of A. cearensis stem bark decoction, for its possible potential as a food conservation agent. The chemical compounds were characterized by one- and two-dimensional 1H and 13C NMR analyses and Liquid Chromatography-Mass Spectrometry (LCMS). The compounds of coumarin, amburosides A and B, and glycosylated (Z)-o-coumaric acid. Using the plaque microdilution technique, the antimicrobial action was tested on Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria monocytogenes. The decoction demonstrated antimicrobial activity on Gram-positive bacteria. This was encouraging because natural antimicrobials are beneficial for food production, as they can inhibit the pathogenic microorganisms and boost the quality of hygiene and cleanliness.

scholarly journals Synthesis and Characterization of Gellan Gum-Pyridoxine Nanoparticle for Treatment of Localized Peripheral Neuropathy

2019 ◽  
Vol 9 (1S4) ◽  
pp. 576-580
Keyword(s):  
Antimicrobial Activity ◽  
Peripheral Neuropathy ◽  
Release Kinetics ◽  
Drug Carrier ◽  
Gellan Gum ◽  
Synthesis And Characterization ◽  
Antioxidant Assay ◽  
Gram Positive Bacteria ◽  
Kinetics Of

Biopolymer has full application as a drug carrier and scaffold in tissue engineering because of its biodegradability and non-toxicity. The present study is focused on novel biopolymer gellan gum as a drug delivery agent. The objective of the study is to synthesize the gellan gum nanoparticle by solvent evaporation emulsification method and characterize it using SEM, DLS, FTIR, and XRD. As pyridoxine is effectively used to treat diabetic peripheral neuropathy, it has been encapsulated with gellan gum and characterized. The antioxidant assay was performed using ABTS reagent, and the activity increases with increasing concentration of nanoparticle. Also, it has significant antimicrobial activity against gram-positive bacteria. Apart from this, the drug release kinetics of the gellan gum- pyridoxine nanoparticle was studied.

scholarly journals Characterization of uterine heterogeneous nuclear ribonucleic acid and the effect of oestradiol-17β on its synthesis

1978 ◽  
Vol 172 (3) ◽  
pp. 587-593 ◽  
Author(s):  
S Aziz ◽  
J T Knowler
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Early Response ◽  
Oestrogen Treatment ◽  
Size Profile ◽  
Immature Rats ◽  
Nuclear Rna ◽  
Kinetics Of ◽  
Molecular Weight Fractions

An early response to the administration of oestradiol-17 beta to immature rats is a dramatic stimulation in the synthesis of uterine hnRNA (heterogenous nuclear RNA). High-molecular-weight fractions of the hnRNA were purified and subfractionated on poly(U)-Sepharose into fractions that differed in their poly(A) content and their size profile on polyacrylamide gels. Oestrogen treatment of the rats stimulated the synthesis of all three fractions of high-molecular-weight hnRNA, but the kinetics of synthesis, degree of stimulation and size distribution of the newly synthesize RNA differed in each fraction.

scholarly journals Identification of a Novel Prostaglandin F2α Synthase in Trypanosoma brucei

2000 ◽  
Vol 192 (9) ◽  
pp. 1327-1338 ◽  
Author(s):  
Bruno Kilunga Kubata ◽  
Michael Duszenko ◽  
Zakayi Kabututu ◽  
Marc Rawer ◽  
Alexander Szallies ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Protozoan Parasite ◽  
African Trypanosomiasis ◽  
Ovarian Dysfunction ◽  
Logarithmic Growth Phase ◽  
African Trypanosomes ◽  
Its Gene ◽  
Logarithmic Growth

Members of the genus Trypanosoma cause African trypanosomiasis in humans and animals in Africa. Infection of mammals by African trypanosomes is characterized by an upregulation of prostaglandin (PG) production in the plasma and cerebrospinal fluid. These metabolites of arachidonic acid (AA) may, in part, be responsible for symptoms such as fever, headache, immunosuppression, deep muscle hyperaesthesia, miscarriage, ovarian dysfunction, sleepiness, and other symptoms observed in patients with chronic African trypanosomiasis. Here, we show that the protozoan parasite T. brucei is involved in PG production and that it produces PGs enzymatically from AA and its metabolite, PGH2. Among all PGs synthesized, PGF2α was the major prostanoid produced by trypanosome lysates. We have purified a novel T. brucei PGF2α synthase (TbPGFS) and cloned its cDNA. Phylogenetic analysis and molecular properties revealed that TbPGFS is completely distinct from mammalian PGF synthases. We also found that TbPGFS mRNA expression and TbPGFS activity were high in the early logarithmic growth phase and low during the stationary phase. The characterization of TbPGFS and its gene in T. brucei provides a basis for the molecular analysis of the role of parasite-derived PGF2α in the physiology of the parasite and the pathogenesis of African trypanosomiasis.

scholarly journals Molecular characterization of plasmids in Salmonella enteritidis phage types

1993 ◽  
Vol 110 (2) ◽  
pp. 209-216 ◽  
Author(s):  
D. J. Brown ◽  
E. J. Threlfall ◽  
M. D. Hampton ◽  
B. Rowe
Keyword(s):  
Molecular Weight ◽  
Dna Hybridization ◽  
Type Strain ◽  
Salmonella Enteritidis ◽  
Phage Type ◽  
Oligonucleotide Probes ◽  
Phage Types ◽  
Type Strains ◽  
Weight Groups

SUMMARYPlasmids in selected type strains of 26 of the Salmonella enteritidis phage types have been characterized by restriction enzyme fingerprinting and by DNA–DNA hybridization with oligonucleotide probes for Salmonella plasmid virulence (Spv) genes. With one exception, the fingerprints of the 38 MDa plasmids studied were homogeneous but there was heterogeneity in the fingerprints of 59 MDa plasmids found in 4 of the type strains. However all 38 MDa and 59 MDa plasmids were related as was a 45 MDa plasmid identified in the type strain of phage type 19. A 3·5 kb fragment homologous to SpvC was conserved in Hind III digests of all 38 MDa and 59 MDa plasmids, and in the related 45 MDa plasmid. In contrast a 65 MDa plasmid found in the type strain of phage type 10 was not related to these three plasmid molecular weight groups and did not carry the SpvC gene.

scholarly journals Isolation and Identification of Lactobacillus plantarum C010 and Growth Kinetics of its Batch Fermentation

2021 ◽  
Author(s):  
Jinyue Dai ◽  
Limin fang ◽  
Manmin Zhang ◽  
Huaili Deng ◽  
Xin Cheng ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Batch Fermentation ◽  
Proteinase K ◽  
Isolation And Identification ◽  
16S Rdna Gene ◽  
Logarithmic Growth Phase ◽  
Gene Sequence Analysis ◽  
Kinetics Of ◽  
Logarithmic Growth ◽  
Chilled Pork

Abstract Chilled pork is pursuit by people due to its delicious and delicate taste, but it is still susceptible to microbial contamination even under refrigerated conditions. Consequently, to explore microbial preservatives for chilled pork, in this study, the specific spoilage organism Pseudomonas koreensis PS1 from spoiled chilled pork as the indicator was used to isolate the bacteriocin-producing lactic acid bacteria from the soils and fresh cow dungs. Among six bacteriocin-producing bacteria from 182 isolates, the strain C010 with higher-yielding, broad-spectrum, subculture stability and protease (pepsin, trypsin and proteinase K) sensitive was selected and identified as Lactobacillus plantarum based on morphological, biochemical and 16S rDNA gene sequence analysis. Simultaneously, the crude bacteriocin of L. plantarum C010 was stable under high temperature and ultraviolet conditions. The kinetics of bacterial growth and bacteriocin production of L. plantarum C010 were analyzed in batch fermentation. Bacteriocin was produced throughout the logarithmic growth phase and the Leudeking-piret model could characterize the synthesis of bacteriocin well. This present study indicates that bacteriocin-producing L. plantarum C010 has promising potentials to control the specific spoilage organism and can be used as the bio-preservative in food.

scholarly journals Characterization of silver nanoparticles and evaluation of their antimicrobial effect on Salmonella

2020 ◽  
Vol 9 (9) ◽  
pp. e103996435
Author(s):  
Luana Virgínia Souza ◽  
Daniela Abrantes Leal ◽  
Tayara Rodrigues da Costa ◽  
Regina Célia Santos Mendonça
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Food Industry ◽  
Salmonella Enteritidis ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Synthesis Methods ◽  
Ag Nps ◽  
Two Populations

Currently, the success of nanotechnology affects several areas of science, medicine, technology and, especially, the food industry. Silver nanoparticles (Ag-NPs) stand out, with their antimicrobial effect. Salmonella is a cause of foodborne diseases and there are reports of resistant serotypes. The use of Ag-NPs is an alternative for bacterial control in foods. The aim of this study was synthesize, characterize and verify the antimicrobial activity of Ag-NPs on serotypes of Salmonella. The  size of Ag-NPs was estimated and it was possible to detect two populations of 4.7 ± 0.09 and 35.7 ± 2.12. The zeta potential was -33.7 ± 11.8 mV indicating good dispersion stability.Ag-NP antimicrobial activity was determined from minimum inhibitory concentration (MIC).The lowest MIC found was 4.7 μg·mL-1 for Salmonella Enteritidis and the highest was 27.7 μg·mL-1 for Salmonella Infantis 1 isolate.The use of Ag-NPs is promising with respect to antimicrobial activity, however, improvements in synthesis methods should be explored in order to make commercial use viable.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

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