Phytoplankton and microzooplankton comprise the base and the first link of the marine food web, respectively. These microbes are key drivers of marine carbon and nutrient cycles. Phytoplankton convert atmospheric CO₂ into organic carbon, and microzooplankton consume phytoplankton, packaging phytoplankton carbon into particulate forms that have a variety of fates:...
The mechanisms of substrate recognition by regulatory proteases are not well understood. Presently, two opposing models have arisen to describe E. coil Lon's ability to discriminate between substrates: one suggests the N-terminus involvement while the second suggests the C-terminus involvement. In this project, the role of the C-terminal domain as...
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...
The ability of Streptococcus diacetilactis to inhibit a variety of
food-borne pathogens and spoilage organisms in milk and broth cultures
was demonstrated. Test organisms inhibited included Pseudomonas
and Alcaligenes species, Eschericia coli, Salmonella, Staphylococcus
aureus, Clostridium perfringens and Vibrio parahaemolyticus.
In general, approximately 99.0% and 99.9% inhibition was
observed in...
Roles of lactic acid bacteria in flour pre-ferment and white
bread were investigated. Volatile compounds produced by the
organisms were identified using gas-liquid chromatography (GLC).
Lactic acid bacteria were isolated from domestic commercial
compressed yeast and active dry yeast. Numbers per gram of
sample were 10⁸ to 10⁹ in compressed...
The most frequent cause of insufficient acid production during
fermentation of dairy products is bacteriophage infection of lactic
starter cultures. Previously, efforts to minimize this problem have
dealt primarily with the host range relationships of the viruses and
susceptibility patterns of the lactic streptococci. This study was
undertaken to characterize...
The ability of Propionibacterium shermanii to produce
growth metabolites which were inhibitory to food spoilage
indicator organisms was investigated. Asperqillus niqer,
a Pseudomonas species and Kluyveromyces fraqilis were the
spoilage indicators chosen to represent molds, gram
negative psychrotrophic bacteria and yeasts, respectively.
Supplementation of milk or whey based media was...
The concentrations of iodophor necessary to reduce the activity
of several metabolic enzyme systems 50 percent was used as the
basic approach in attempts to elucidate the mechanism of germicidal
action of iodine. For comparisons, a chlorine-releasing germicide
(Trichlorocide) and a quaternary ammonium compound were also
tested. It was found...