The Water Relations of Growth and Respiration of Salmonella Oranienburg At 30°C

Christian, J. H. B.

doi:10.1071/bi9550490

Cited by 89 publications

(36 citation statements)

References 3 publications

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“…Similar results, indicating a relationship between K content and medium osmolality, have been reported for E. coli by 0rskov (15) and for S. oranienburg by Christian (9). Both these authors measured K content after resuspending bacteria in a buffer which did not allow growth and whose osmolality was greater than that of the growth medium, so that their experiments indicate the effect of upshock on non-growing cells.…”

Section: Extracellular K Conc (Mm)supporting

confidence: 71%

“…The conclusion that these changes in K content are due to the osmotic pressure difference created by the agents used is supported by experiments with glycerol, which, when added in 0.3 M concentration to the standard medium containing glucose as substrate, had no effect on the [K]i of these bacteria. Glycerol is known to penetrate bacteria readily (8) and has been reported to be without effect on the K content of another Gramnegative organism, Salmonella oranienburg (9). Growth in media of different osmolality has effects in addition to those on * Errors are standard errors of the mean; the figure in parentheses indicates the number of determinations.…”

Section: K and Na Contentmentioning

confidence: 99%

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Cation Transport in Escherichia coli

Epstein

Schultz

1965

The Journal of General Physiology

323

108

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AB ST R AC T Measurement of cellular K and Na concentrations in growingEscherichia coli indicates that the osmolality of the medium is a major determinant of the cell K concentration. In contrast, the cell Na concentration is independent of the medium osmolality and is largely dependent on the Na concentration of the medium. Sudden changes in the osmolality of the medium lead to rapid changes in K content. Washing the cells with solutions of lower osmolality results in a very rapid loss of K, which is greater in more dilute and in cold solutions. A sudden increase in the osmolality of the growth medium produces a rapid uptake of K by a mechanism whose rate is a saturable function of the K concentration of the medium and which appears to involve an exchange of K for cellular H.In previous studies of this series it has been shown that the ionic composition of Escherichia coli is (a) constant in the logarithmic phase of growth, (b) changes as the pH declines in the stationary phase, and (c) returns rapidly to the cation content typical of the logarithmic phase of growth when the stationary phase cells are resuspended in fresh medium (1, 2). In the present study we have sought further evidence on the role of K in this organism, and the mechanism of its movement, by investigating some of the factors which determine the K and Na contents of exponentially growing cells. The results indicate that the osmolality of the medium is a major determinant of the K content of these cells, and that abrupt changes in this osmolality result in rapid changes in the intracellular concentration of this cation. METHODS MediaThe standard medium used in these studies was composed of: Na 2 HPO 4 56 mM, NaH 2 PO 4 14 mM, NaCl 10 mM, NH 4 Cl 10 mM, KCI 2.5 mM, Na 2 SO 4 1 m, MgSO4 0.4 m, FeC13 1.5 pIM, CuSO 4 0.2 /uM, (NH 4 )MoO4 0.15 pM, and glucose 55 mM. After autoclaving, this medium had an osmolality of 260 to 270 mOsM and a pH of 7.15 to 7.20. Media of greater osmolality, prepared by the addition of NaCI, sucrose,

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Section: Extracellular K Conc (Mm)supporting

confidence: 71%

Section: K and Na Contentmentioning

confidence: 99%

Cation Transport in Escherichia coli

Epstein

Schultz

1965

The Journal of General Physiology

323

108

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“…About one-third of the potassium was lost, suggesting that this ion may be of major importance in osmotic regulation of bacterial cells. Evidence supporting this suggestion has also been obtained from potassium accumulation studies with Salmonella oranienburg (Christian, 1955).…”

Section: Discussionsupporting

confidence: 61%

Lysis of Vibrio costicolus by Osmotic Shock

Christian

Ingram

1959

Journal of General Microbiology

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SUMMARY : Suspensions of the halophilic organism Vibrio costicolus 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 0.33 M : when the organisms were suspended similarly in KCl or NH,CI solutions, lysis began at a concentration above 0 . 8~.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 M-mercuric chloride. Addition of cetyltrimethylammonium bromide (200 pg./ml.) increased resistance to lysis in both NaCl and KCl solutions, Organisms grown in media of NaCl concentrations ranging from 0.5 to 3 . 0~ began to lyse a t a NaCl concentration one-third of that present during growth. Organisms suspended in NaCl 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 5 0 % 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.Many types of bacteria lyse when transferred from concentrated growth media to more dilute solutions or to water, and this behaviour is particularly common among halophilic strains. Robinson & Katznelson (1953) noted that the extremely halophilic Pseudomonus salinaria, grown in a medium containing 16 yo (w/v) NaC1, underwent rapid plasmoptysis on transfer to 1 , 2 or 4 yo NaCl and showed some deterioration of structure in 8 % NaC1. However, no attempts appear to have been made to study quantitatively the degree of lysis resulting from osmotic shock. Christian & Ingram (1959) found that the freezing-point depression of heated bacteria was similar to that of their growth medium over a wide range of salt concentra.tions. It was of interest, therefore, to investigate the relationship between the osmotic sensitivity of such organisms and the salt concentration of the environment. This paper describes a technique for measurement of osmotic lysis, and reports the effects of a number of factors on the osmotic sensitivity of a moderate halophile, Vibrio costicolus. METHODS Organism.The test organism was a strain of Vibrio costicolus kindly supMedia. The organism was grown in liquid media containing 0.5% (w/v)

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“…Cells of Salmonella oranienburg respiring in concentrated solutions accumulated much more potassium than in dilute media (Christian, 1955), suggesting that potassium largely controlled the water activity (a,) within the cell. Further, the salmonellas are relatively intolerant of high salt concentrations or low a, (Christian & Scott, 1953) and contain little potassium (Barber, 1931; Christian, 1958), while the staphylococci are very salt tolerant (Maitland & Martyn, 1948;Scott, 1953) and are very rich in potassium (Barber, 1931).…”

Section: Introductionmentioning

confidence: 99%