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Biomedical subjects

T H Melville

Publications and source records attributed to T H Melville.

At least 19 recordsLinked to original sources
PubMed1981

Mixed culture studies of Streptococcus mitis and oral enterococci.

Strains of Streptococcus mitis and oral enterococci were grown in mixed culture in 0.5% peptone, 1.0% peptone and 1.0% peptone supplemented with 0.5% glucose. In all three media the enterococci inhibited the S. mitis strains. The inhibition was strongest in the glucose supplemented broths, probably due to pH toxicity. Inhibition in the unsupplemented broths was not similarly caused, but no other inhibitory factors could be isolated from these culture.

Culture Media↗
PubMed1979

Inhibitory activity of Streptococcus mitis against oral bacteria.

The antagonistic properties of three strains of Streptococcus mitis were investigated. They were found to inhibit a wide range of oral bacteria; Gram-positive and Gram-negative, facultative and anaerobic species being susceptible. The S. mitis strains were shown to be producing hydrogen peroxide, this being partially responsible for the aerobic inhibitory activity. A second inhibitory factor(s) was also produced, aerobically and anaerobically, although this could not be isolated. A limited characterization of this factor was undertaken using plate cultures.

Actinomycetaceae↗
PubMed1978

The influence of certain growth conditions on the phosphatase activity of Streptococcus mutans grown in batch and continuous culture.

Acid phosphatase activity was detected in Streptococcus mutans strain NCTC 10832, and both acid and alkaline phosphatase in strains 2M2 and K1R. In batch culture, activity was maximal by mid exponential phase for 2M2 and at the end of this phase for NCTC 10832. Alkaline, but not acid, phosphatase activity of 2M2 and K1R increased when the inorganic phosphate in the medium was low; this was considered due, at least partly, to inducible or derepressible enzymes. In continuous culture, acid phosphatase activity of NCTC 10832 varied with the sugar substrate. The activity was increased by cell disruption and the degree of this increase for cells grown on different sugars parallelled the amounts of extracellular, insoluble polysaccharide produced on those sugars. Activity was highest for glucose-grown whole cells and for sucrose-grown disrupted cells.

Acid Phosphatase↗