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Filtering by: Creator Woodruff, William C. Remove constraint Creator: Woodruff, William C. Advisor Sandine, William E. Remove constraint Advisor: Sandine, William E.

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  • Growth of lactococci relative to antibiotic and quaternary ammonium compounds

    Creator:
    Valladao, Marilin
    Abstract:
    The work presented in this thesis is concerned with the effect of several antibiotics and quaternary ammonium sanitizers upon growth of lactic acid bacteria. Section I reports the purification of beta-lactamase from Lactococcus cremoris PR-108, by ion exchange chromatography, using the chromogenic substrate pyridine-2-azo-p-dimethylaniline (PADAC) as the enzymatic indicator. Section...
    Resource Type:
    Masters Thesis
    Full Text:
    AMMONIUM CrOUNDS Redacted for PrivacyAbstract approved: William E. Sandine The work presented in this

  • Studies to improve lactic acid bacterial starter cultures

    Creator:
    Khosravi, Lewa
    Abstract:
    Three commercial sausage starter cultures were grown in an internal-pH-controlled medium (PHASE 4) and in a soluble phosphate-buffered medium. The cultures were tested by comparing viable counts before and after freezing at -40 C or freeze-drying and subsequent storage for 3 months in the frozen or dried state. Strains varied...
    Resource Type:
    Dissertation
    Full Text:
    . Stephen Kaattari, Prof. Floyd W. Bodyfelt, Dr. Donald E. Mattson , Dr. William C. Denison and Dr

  • Mechanisms of lactose metabolism by strains of Streptococcus lactis

    Creator:
    Walter, Leslie Alva
    Abstract:
    Rapid acid production by lactic streptococci used in the manufacture of fermented dairy products is essential to the economy of the industry and to the public health of consumers. There remains to developed, however, an adequate laboratory procedure to detect and distinguish between slow and fast strains of these bacteria....
    Resource Type:
    Masters Thesis
    Full Text:
    : MECHANISMS OF LACTOSE METABOLISM BY STRAINS OF STREPTOCOCCUS LACTIS Redacted for Privacy William E. Sandine

  • 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:
    84. l' C, 84. 4°C and 83. 7'C, respectively. These values corresponded to guanine plus cytosine

  • Effect of selected lactic acid bacteria on the growth of food-borne pathogens and spoilage microorganisms in raw milk and milk products

    Creator:
    Al-Zoreky, Nageb
    Abstract:
    Several lactic acid bacteria (LAB) of the Lactococcus, Lactobacillus, Leuconostoc and Pediococcus genera were screened for inhibition of food-borne pathogens and spoilage microorganisms in raw milk and dairy products. Listeria monocytogenes was killed by Lactococcus lactis subsp. lactis and Pediococcus pentosaceus due to their production of bacteriocin-type inhibitors. Staphylococcus aureus...
    Resource Type:
    Dissertation
    Full Text:
    Spoilage Microorganisms in Raw Milk And Milk Products Abstract Approved: Dr. William E

  • Performance of Oregon derived malolactic bacteria : studies on storage stability and their use in the wine industry

    Creator:
    Micheals, Nancy J.
    Abstract:
    Commercial vats of Chardonnay and Pinot Noir were inoculated during yeast fermentation with starter cultures containing 10⁷ - 10⁹ cfu/ml of the malolactic bacteria Leuconostoc oenos Erla and Ey2d in lots ranging from 55 to 4,000 gallons. Chardonnay inoculated with Ey2d completed MLF in an average of 56 days at...
    Resource Type:
    Masters Thesis
    Full Text:
    . Abstract approved: Redacted for Privacy Dr. William E. Sandine Commercial vats of Chardonnay and Pinot

  • Characterization of Oregon-derived malo-lactic bacteria : fermentation properties and storage stability

    Creator:
    Dohman, Thomas Philip
    Abstract:
    Gram positive cocci isolated from Oregon wines were characterized and their relative malate fermentation abilities compared. They were heterofermentative, catalase negative, and facultatively anaerobic. Glucose, fructose, cellobiose, maltose, ribose, trehalose, salicin and esculin were fermented by all strains. Arabinose was fermented weakly but lactose, raffinose, sucrose, xylose, rhamnose, mannose and...
    Resource Type:
    Masters Thesis
    Full Text:
    : Redacted for Privacy Dr. William E. Sandine Gram positive cocci isolated from Oregon wines were

  • Isolation of auxotrophic mutants of Bacillus cereus

    Creator:
    Keng, Jiun Guang
    Abstract:
    Bacillus cereus excretes large amounts of penicillinase into growth media during incubation, hence the widely-used penicillin selection technique for isolating biochemical mutants of bacteria is not applicable to this species. Genetic transfer in B. cereus has not been reported; this is partly due to the lack of an effective isolation...
    Resource Type:
    Masters Thesis
    Full Text:
    pnesence of 6% DES, however, 2x10-3 auxotrophs were obtained with 6464D. trt was found that the mutageni-c

  • Characterization of dairy leuconostocs and method to use Leuconostoc mesenteroides ssp. cremoris to improve milk fermentations

    Creator:
    Levata-Jovanovic, Marina
    Abstract:
    Dairy leuconostocs are frequently used as aroma-producing bacteria in mesophilic cultures used as starters for milk fermentations. Sixty Leuconostoc strains from different culture collections were studied taxonomically for species identification. Based on morphological, physiological and biochemical tests, twenty of these strains were typed as Leuconostoc mesenteroides ssp. cremoris (Leu. cremoris)....
    Resource Type:
    Masters Thesis
    Full Text:
    of diacetyl or acetoin. Addition of citric acid after preincubation (24 hr, 28°C) resulted in

  • Characterization of thermophilic rod and coccus starter strains used in mozzarella cheese manufacture

    Creator:
    Faessler, Patrick Charles
    Abstract:
    The present investigation was undertaken to characterize a number of strains of Lactobacillus bulgaricus and Streptococcus thermophilus intended for use by a commercial starter supply company. Thorough characterization of each culture was required in order to combine compatible strains so that their usefulness in Mozzarella cheese manufacture would be maximized....
    Resource Type:
    Masters Thesis
    Full Text:
    Redacted for Privacy Abstract approved: Dr. William E. Sandine The present investigation was