Peter R. Stewart

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Saccharomyces cerevisiae andCandida parapsilosis were grown aerobically and micro-aerobically in continuous culture and the energetic efficiency (Y ATP) and the maintenance energy requirements compared. The bioenergetic parameters were determined using a gas-balance technique, and from cell yield decrements at low dilution rates. The data show that for(More)
A recently proposed polythetic definition of virus species appears easily applicable to bacteriophages. Criteria for classification of tailed phages are evaluated. Morphology, DNA homology, and serology are the most important criteria for delineation of species, but no single criterion is satisfactory. Dot-blot hybridization and seroneutralization may(More)
Myosin purified from Dictyostelium amoebae has approximately 10% by weight of RNA associated with it, unless specific steps (DEAE cellulose chromatography or RNase digestion) are taken to remove it. This RNA has significant effects on the structural states formed by the myosin at low ionic strength in the presence of Mg2+. Rapid precipitation of RNA-free(More)
Fifteen bacteriophages representative of the serological and lytic groups of the International Typing Set forStaphylococcus aureus were examined for genomic homology by DNA hybridization and by analysis of high resolution thermal denaturation profiles. Phages 11 and 80 α, not part of the set, were also examined. DNA homology measured by filter hybridization(More)
Proton magnetic resonance (PMR) and carbon-13 magnetic resonance (CMR) spectra of intact, unsonicated yeast and rat liver motochondria show differences which may be correlated with the composition of the membranes. High resolution PMR and CMR signals in intact yeast mitochondria have been assigned to regions of fluid lipid-lipid interaction on the basis of(More)
Strains of Staphylococcus aureus, an opportunistic pathogen commonly found on human skin, were exposed to sunlight and UV C radiation, and the lethal and mutational effects measured. Sunlight killed cells with an inactivation constant of 3×10-5 per joule per square metre; UV C was much more lethal, giving an inactivation constant of approximately 0.1 per(More)
The effects of UV-B radiation generated in the laboratory and as a component of sunlight on the viability and particular biochemical activities of the bacterium Staphylococcus aureus have been examined. UV-B radiation progressively inhibits protein synthesis (assayed as 3H-alanine incorporation) and kills cells. Cell respiration, and RNA and DNA synthesis(More)
Membrane biology is notorious for its remarkable, and often strong dependence on the supposedly irrelevant choice of ion pair of background salt solution. While experimentally well known, there has been no progress towards any real theoretical understanding until very recently. We have demonstrated that an important source behind these Hofmeister effects is(More)
Cytochemical and ultrastructural analysis of wild-type cells of Saccharomyces cerevisiac, grown aerobically in a glucose-limited chemostat, shows that cytochrome c peroxidase is localized between the membranes of the cristae, that is, in the intracristal space. This enzyme is thus positioned appropriately within the organelle to act as an alternate terminal(More)