Journal article
Antibacterial effect of protamine assayed by impedimetry
Impedimetric measurements were used to assay the antibacterial effect of protamine. A good linear correlation between the impedance detection time and the initial cell counts was obtained (r = 0 . 99, n = 2). As basic peptides may cause clumping of cells, this correlation curve was used when estimating the cell number after protamine treatment, rather than colony counts.
Protamine from salmon killed growing Gram- positive bacteria and significantly inhibited growth of Gram- negative bacteria in Tryptone Soy Broth (TSB) at 25 degrees C. In general Gram-positive bacteria were more sensitive to protamine than Gram-negative bacteria; the minimum inhibitory concentrations (MIG) determined for Gram-positive strains varied from 20 to 1000 mu g ml(-1) and for Gram-negative strains from 500 mu g ml(-1) to more than 4000 mu g ml(-1).
The effect of protamine on non-growing Listeria monocytogenes Scott A suspended in buffer was not lethal as was the effect on growing cells; however, protamine (50-500 mu g ml(-1)) killed the Gram-negative fish spoilage bacteria Shewanella putrefaciens when the live cells were suspended in buffer.
Language: | English |
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Year: | 1995 |
Pages: | 297-303 |
ISSN: | 20565232 and 00218847 |
Types: | Journal article |
DOI: | 10.1111/j.1365-2672.1995.tb05029.x |
ORCIDs: | Gram, Lone |