SUMMARY: Suspensions of the halophilic organism lysed when subjected to sufficient osmotic shock; this was revealed as a marked fall in optical density. Organisms in the logarithmic phase of growth, grown in media containing m-NaCl, when suspended in NaCl or LiCl solutions with concentrations m or lower lysed when the concentration was below 0·33m: when the organisms were suspended similarly in KCI or NHCI solutions, lysis began at a concentration above 0·8 m. Older organisms were more resistant to lysis. Lysis was little affected by replacement of chloride by other univalent anions, by pH values from 4 to 10 or by previous incubation with 10m-mercuric chloride. Addition of cetyltrimethylammonium bromide (200 μg./ml.) increased resistance to lysis in both NaCI and KCI solutions. Organisms grown in media of NaCI concentrations ranging from 0·5 to 3·0m began to lyse at a NaCI concentration one-third of that present during growth. Organisms suspended in NaCI solutions of one-half the concentration in which they had been grown equilibrated promptly to the new environment; this was shown by a decrease of 50 % in the salt concentration at which lysis then began. When organisms were transferred to salt concentrations higher than that of the growth medium, the osmotic sensitivity was not affected. It is concluded that the osmotic status of these organisms is controlled chiefly by small ions or molecules which leak rapidly from the cells on transfer to dilute environments


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error