Search Constraints

Start Over
Filtering by: Has journal Journal of Nuclear Materials Remove constraint Has journal: Journal of Nuclear Materials Academic Affiliation Microbiology Remove constraint Academic Affiliation: Microbiology Subject Streptococcus Remove constraint Subject: Streptococcus

Search Results

  • Control of acid production and β-galactosidase synthesis in lactic streptococci

    Creator:
    Citti, James Edward
    Abstract:
    The public health and economic significance of rapid acid production by lactic streptococci in controlled dairy fermentations is well known. However, the fast acid-producing characteristic of these organisms is not stable, and cultures of fast organisms have been shown to contain slow cells. These studies were carried out to characterize...
    Resource Type:
    Dissertation
    Full Text:
    MATERIALS AND METHODS 11 Studies on Slow and Fast Acid Production 11 Culture and Isolation of Slow

  • Metabolism of aroma bacteria as related to diacetyl production

    Creator:
    Brown, Ruth Elaine
    Abstract:
    Factors influencing diacetyl production by the aroma bacteria Leuconostoc citrovorum and Streptococcus diacetilactis were investigated. When grown in association with lactic streptococci, L. citrovorum strain 91404 decreased in cell numbers from 10⁸ to 10⁶ over two weeks of daily subculturing in sterile non-fat milk incubated at 21°C. The ability to...
    Resource Type:
    Masters Thesis
    Full Text:
    variety of sources such as green plant materials and raw milk where they find the nutrients required

  • Purification and properties of Streptococcus lactis β-galactosidase

    Creator:
    McFeters, Gordon A.
    Abstract:
    Experiments were carried out to purify and characterize the galactosidase of the Streptococcus lactis 7962. Purification was accomplished using standard procedures; however the lability of the enzyme to numerous treatments limited the techniques that could be used and the amount of active enzyme recovered. Gel filtration revealed that the enzyme...
    Resource Type:
    Dissertation
    Full Text:
    Protection. TABLE OF CONTENTS INTRODUCTION HISTORICAL REVIEW 1 3 MATERIALS AND METHODS 8

  • The inhibitory effect of Streptococcus diacetilactis on the growth of Staphylococcus aureus in milk and vanilla cream filling

    Creator:
    Radich, Ruth Elaine
    Abstract:
    Trypticase-Soy Broth (TSB) was inoculated with Streptococcus diacetilactis, incubated at 21C for 24 hours and centrifuged to remove the cells. When the spent TSB was inoculated with Staphylococcus aureus, it allowed 99.8% less growth than fresh TSB. If the spent TSB were supplemented with 0.08 μg/ml of niacinamide, this inhibition...
    Resource Type:
    Masters Thesis
    Full Text:
    Filling as a Medium for Staphylococci 11 MATERIALS AND METHODS 12 Sources of Cultures 12 Culture

  • Host range and chemical composition of lactic streptococcal bacteriophages

    Creator:
    Henning, David Ralph
    Abstract:
    Comparisons were made of the abilities of Streptococcus lactis, Streptococcus cremoris and Streptococcus diacetilactis bacteriophages to endure various laboratory isolation and storage treatments. Neutralization of Cottage cheese whey containing phages offered no survival advantage over unneutralized samples, refrigeration of neutral and acid whey samples increased the survival of only the...
    Resource Type:
    Dissertation
    Full Text:
    Discussion sections of this thesis. . 10 MATERIALS AND METHODS Bacterial Cultures and

  • Studies on the inhibition of spoilage organisms in Cottage cheese by lactic streptococcus organisms

    Creator:
    Hauser, Bruce Allen
    Abstract:
    A report in the literature suggesting that the use of cottage cheese dressing cultured with S. diacetilactis would afford enhanced flavor and shelf life in the finished product prompted this study to examine reasons for its effectiveness. The method used involved addition of a culture of S. diacetilactis 18-16 to...
    Resource Type:
    Masters Thesis
    Full Text:
    inhibitory property of certain materials against a test organism. The material 26 to be tested is put

  • Antimicrobial resistance and plasmid properties of Leuconostoc and group N Streptococcus

    Creator:
    Orberg, Paulo K.
    Abstract:
    A method for rapid isolation of plasmid DNA from group N streptococci was developed. Chief advantages of the method were simplicity, the utilization of microliter quantities of reagents, and the obtainment of preparations highly enriched for covalently closed circular plasmid DNA. The method was also applied to over 15 Leuconostoc...
    Resource Type:
    Dissertation
    Full Text:
    products, or plant material (11,12). These habitats are shared (29) by dairy streptococci of the group N

  • Pathways and enzymes involved in glucose catabolism by lactic streptococci

    Creator:
    Nandan, Rajiva
    Abstract:
    The enzymes and pathways involved in the catabolism of glucose by several strains of Streptococcus diacetilactis, Streptococcus cremoris, and Streptococcus lactis, commonly called the lactic streptococci, were studied. The presence of aldolase, triosephosphate isomerase and alcohol dehydrogenase in these organisms provided evidence for the operation of the Embden-Meyerhof-Parnas (EMP) pathway...
    Resource Type:
    Dissertation
    Full Text:
    Decarboxylation of Alpha -keto Acids 21 MATERIALS AND METHODS 30 Microbiological Methods 30 Cultures Used 30

  • Genetic homology and exchange in lactic acid streptococci

    Creator:
    Knittel, Martin Dean
    Abstract:
    The dairy industry relies primarily on consistent acid production by the lactic streptococci for the manufacture of certain cheeses and fermented dairy products. Variation in these cultures due to genetic exchange has not been thoroughly investigated. This study was undertaken to determine if genetic homology exists within the lactic group,...
    Resource Type:
    Dissertation
    Full Text:
    undertaking. TABLE OF CONTENTS Page INTRODUCTION 1 HISTORICAL REVIEW 4 METHODS AND MATERIALS 13