Lactobacillus Helveticus
Mostrando 13-24 de 80 artigos, teses e dissertações.
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13. Determinação da microbiota bacteriana de mosto e de dornas na fermentação alcoolica
Samples of concentrated yeast cell suspension diluted before the addition of sulfuric acid, of the same concentrated yeast cell suspension after addition and action of sulfuric acid, of must added to the same concentrated yeast cell suspension collected and of fermented must from the same fermentation tank, were collected between July and December of 1986, a
Publicado em: 1990
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14. Plasmids, Lactic Acid Production, and N-Acetyl-d-Glucosamine Fermentation in Lactobacillus helveticus subsp. jugurti
Two lactobacillus strains, Lactobacillus helveticus subsp. jugurti S13-8 and L. helveticus subsp. jugurti S36-2, were examined for the presence of plasmids. Plasmids of 16.45, 13.03, and 11.83 kilobases (kb) were found in the first, low lactic acid-producing strain; their function is not presently known. A single plasmid species of 13.17 kb was found in the
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15. A Lactobacillus helveticus-Specific DNA Probe Detects Restriction Fragment Length Polymorphisms in This Species
A cloned 2-kb EcoRI fragment (fragment f) from a 34-kb plasmid of Lactobacillus helveticus CNRZ 1094 was shown by dot blot to specifically hybridize to total DNAs of 75 L. helveticus strains. No hybridization was found with L. acidophilus, L. crispatus, L. delbrueckii subsp. bulgaricus, L. delbrueckii subsp. lactis, L. gasseri, or L. intestinalis strains. Wh
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16. Characterization of the Lactobacillus helveticus CNRZ32 pepC gene.
Sequence analysis of the aminopeptidase C gene (pepC) from Lactobacillus helveticus CNRZ32 identified a 1,332-nucleotide open reading frame coding for a polypeptide with motifs characteristic of cysteine proteinases. Homology to the pepC gene appears to be widely distributed among lactic acid bacteria.
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17. Effectiveness of Chemometric Techniques in Discrimination of Lactobacillus helveticus Biotypes from Natural Dairy Starter Cultures on the Basis of Phenotypic Characteristics
Lactobacillus helveticus is the dominant organism in natural starter cultures used for the production of typical Italian cheeses. In this study, 74 L. helveticus strains, isolated from grana and provolone cheese natural whey starters, were distinguished with respect to their origin by using both cell wall protein profiles and chemometric evaluation of some p
American Society for Microbiology.
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18. Genetic Characterization and Physiological Role of Endopeptidase O from Lactobacillus helveticus CNRZ32
A previously identified insert expressing an endopeptidase from a Lactobacillus helveticus CNRZ32 genomic library was characterized. Nucleotide sequence analysis revealed an open reading frame of 1,941 bp encoding a putative protein of 71.2 kDa which contained a zinc-protease motif. Protein homology searches revealed that this enzyme has 40% similarity with
American Society for Microbiology.
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19. Identification and Characterization of Lactobacillus helveticus PepO2, an Endopeptidase with Post-Proline Specificity
A post-proline endopeptidase (PepO2) was detected in cell extracts from a genomic library of Lactobacillus helveticus CNRZ32 by using the synthetic substrate N-acetyl-β-casein-(f203-209)-ρ-nitroanilide in a coupled reaction with aminopeptidase N. Isolates with activity for this substrate contained plasmids with visually indistinguishable restriction profil
American Society for Microbiology.
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20. Molecular Diversity within Lactobacillus helveticus as Revealed by Genotypic Characterization
Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium that is used in the manufacture of Swiss type and long-ripened Italian cheeses, such as Emmental, Grana, and Provolone cheeses. Substantial differences in several technologically important characteristics are found among L. helveticus strains isolated from natural dairy starter
American Society for Microbiology.
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21. Complete nucleotide sequence and characterization of a cryptic plasmid from Lactobacillus helveticus subsp. jugurti.
A small cryptic plasmid, pLJ1, was isolated from Lactobacillus helveticus subsp. jugurti and was cloned into Escherichia coli HB101 by using pBR329 as a vector. Plasmid pLJ1 was 3,292 base pairs long and had single restriction endonuclease sites for PvuII, KpnI, AvaII, Acci, HindIII, and EcoRI. In a maxicell system, pLJ1 produced a protein of about 41 kiloda
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22. Isolation and Characterization of a Slowly Milk-Coagulating Variant of Lactobacillus helveticus Deficient in Purine Biosynthesis
A slowly milk-coagulating variant (Fmc−) of Lactobacillus helveticus CRL 1062, designated S1, was isolated and characterized. Strain S1 possessed all the known essential components required to utilize casein as a nitrogen source, which include functional proteinase and peptidase activities as well as functional amino acid, di- and tripeptide, and oligopept
American Society for Microbiology.
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23. Expression of Six Peptidases from Lactobacillus helveticus in Lactococcus lactis
For development of novel starter strains with improved proteolytic properties, the ability of Lactococcus lactis to produce Lactobacillus helveticus aminopeptidase N (PepN), aminopeptidase C (PepC), X-prolyl dipeptidyl aminopeptidase (PepX), proline iminopeptidase (PepI), prolinase (PepR), and dipeptidase (PepD) was studied by introducing the genes encoding
American Society for Microbiology.
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24. Biodiversity among Lactobacillus helveticus Strains Isolated from Different Natural Whey Starter Cultures as Revealed by Classification Trees
Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium used extensively for manufacturing Swiss type and aged Italian cheese. In this study, the phenotypic and genotypic diversity of strains isolated from different natural dairy starter cultures used for Grana Padano, Parmigiano Reggiano, and Provolone cheeses was investigated by a
American Society for Microbiology.