Volume 47, Issue 2
February 1958, pages 55-113
pp 55-69 February 1958
pp 70-77 February 1958
The dehydrogenase activities of susceptible and sulfanilamide-resistant strains ofB. subtilis grown in peptone or semi-synthetic media have been studied with glucose, glycerol, calcium lactate, sodium pyruvate and ethyl alcohol as substrates. The resistant strain showed a marked decrease in dehydrogenase activities with all the substrates.
The behaviour of the cell-free extracts of susceptible or resistant strains was comparable to those of the corresponding intact cells, indicating that decreased dehydrogenase activities of the resistant strain may not be due to alteration in cell-wall permeability.
pp 78-86 February 1958
The factors governing the activity of endo-cellular PME fromF. vasinfectum as efficiency of extractants, substrate concentration, pH and temperature are reported. The enzyme resembles other mold PME in others. The significance of these observatinos in discussed.
pp 87-96 February 1958
The effect of aureomycin at levels of 2, 5, 20 and 50 parts per million was observed in the case of about 50 bacterial spp. isolated from marine sources.
Seventy per cent. of the bacteria were sensitive to 5 p.p.m. or lesser concentration of the antibiotic. The cocci were more resistant than the Gramnegative rods while sensitivity to aureomycin varied greatly in theBacillus. The lag period before visible growth occurred on agar slopes at room temperature usually varied from 1/2 to 4 days.
Plate counts of fresh fish slime on aureomycin containing agar showed a reduction to 1/3rd at 2 p.p.m. and to 1/25th at 5 p.p.m. level. In the case of the sea-water the count was reduced to 1/5th at 2 p.p.m. and to 1/20th at 5 p.p.m. levels.
The probable implication of these observations on the use of aureomycin in ices and in “initial dips” for preservation of fish is discussed.
pp 97-101 February 1958
pp 102-113 February 1958