Biochemical determination of bacterial morphology and the geometry of cell division

Previc, Edward

doi:10.1016/s0022-5193(70)80010-8

Cited by 57 publications

(39 citation statements)

References 37 publications

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“…In this way, cells are able to achieve a steady-state SA/V over time without requiring a SA/V sensing system. Interestingly, in the 1970’s several papers suggested (Previc, 1970; Pritchard, 1974) that increases in cell size upon nutritional upshift could be the result of the measured mismatch (Sud and Schaechter, 1964) between the increases in volume and wall synthesis following upshift, a suggestion much in line with our current thinking. More broadly, homeostatic mechanisms similar to the “relative rates” model could be applicable beyond SA synthesis, and potentially beyond bacteria, to describe other processes where the rate of some output scales with volume, similar to mechanisms that have been proposed for eukaryotic systems determining the size and shape of cells and organelles (Chan and Marshall, 2012; Levy and Heald, 2012).…”

Section: Discussionsupporting

confidence: 71%

Relative Rates of Surface and Volume Synthesis Set Bacterial Cell Size

Harris

Theriot

2016

Cell

218

413

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Summary Many studies have focused on the mechanisms underlying length and width determination in rod-shaped bacteria. Here, we focus instead on cell surface area to volume ratio (SA/V), and demonstrate that SA/V homeostasis underlies size determination. We propose a model whereby the instantaneous rates of surface and volume synthesis both scale with volume. This model predicts that these relative rates dictate SA/V and that cells approach a new steady-state SA/V exponentially, with a decay constant equal to the volume growth rate. To test this, we exposed diverse bacterial species to sublethal concentrations of a cell wall biosynthesis inhibitor and observed dose-dependent decreases in SA/V. Furthermore, this decrease was exponential and had the expected decay constant. The model also quantitatively describes SA/V alterations induced by other chemical, nutritional, and genetic perturbations. We additionally present evidence for a surface material accumulation threshold underlying division, sensitizing cell length to changes in SA/V requirements.

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Section: Discussionsupporting

confidence: 71%

Relative Rates of Surface and Volume Synthesis Set Bacterial Cell Size

Harris

Theriot

2016

Cell

218

413

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“…Other orientations of wall polymers are also compatible with helical growth. Unfortunately current evidence concerning the orientation of the glycans on the cell surface is inadequate to resolve this issue (11)(12)(13)(14)(15)(16)(17)(18).…”

Section: Discussionmentioning

confidence: 99%

Helical growth of Bacillus subtilis: a new model of cell growth.

Mendelson¹

1976

Proc. Natl. Acad. Sci. U.S.A.

102

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A multiple mutant of Bacillus subtifis that grows in an unusual double-helix morphology was studied. Construction of models led to the assumption that cell surface elongation must proceed in a helical path in this mutant. The observation that all newly formed double-helix clones propagated, after spore outgrowth in fluid culture, consisted of closed-circular structures suggested that double-helix structures are tension-restricted forms. It There is currently very little known concerning the forces and regulatory mechanisms that govern bacterial shape and the relationship of shape to growth. The overly simplistic view that shape-determination emanates directly from the molecular architecture of the cell wall has not been substantiated. Instead a more realistic view now seems to be emerging in which the interaction of forces and structures is recognized as contributing to shape-determination (1). We recently isolated a multiplemutant of Bacillus subtilis that grows in an unusual pattern of amazing complexity. In the course of building models to help visualize these structures, and to analyse the constraints under which they grow, a new theory of cell organization was developed. The basis of this theory is that the cell surface components in rod-shaped cells are organized in a helical pattern. The addition of new cell surface, during growth, follows this helical organization. The relationship of a helical cell surface organization to the helical clones observed will be explored.MATERIALS AND METHODS The helix-producing mutant was isolated from cultures of B. subtilis 168 that carry the div IV-BJ, ura, and met B' markers (2). This strain had been exposed to nitrosoguanidine prior to the isolation of div IV-BJ and presumably carries additional mutation(s) concerned with the helical growth property. Repeated attempts by Dr. W. P. Segel to purify the helix-producing strain led to the isolation of Strain BiS, a smooth colony derivative that produces colonies containing a high percentage of helical cells when grown on tryptose blood agar base medium supplemented with 20,og/ml of uracil (Difco, Detroit, Mich.).Spores of BiS produced by growth on potato agar were used in the experiments reported here. It should be noted' that regardless of growth conditions helical-clones are always found to give rise to some straight cells. The following fluid medium was found to support the growth of helical-clones following spore outgrowth of BIS: Bacto tryptose, 10 g; Bacto beef extract, 3 g; NaCl, 5 g; per liter supplemented with 20 ,.g/ml of uracil. Only 10% or less of BiS spores produce helical growth initially upon outgrowth in this medium.Light microscopy techniques were previously described (3). Clone contour lengths were measured from micrographs using a graphics calculator (Numonics Corp., North Wales, Pa.) connected to a PdP8e computer (Digital Equipment Corp., Maynard, Mass.) (3).Model building employed two, 3-inch (7.62 cm) diameter galvanized cylindrical pipe elbows joined to produce a 6-jointed structure which ca...

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“…The turgor pressure, which is due to the stress in the cell wall, is defined as the hydrostatic pressure across the cell wall that compensates for the difference in water activity between the cytoplasm and the suspending medium so that the electrochemical potential of water is the same on both sides. Alternative theories of cell growth and development (15,16,20) predict different patterns of fluctuations in internal osmotic pressure during the cell cycle. It therefore is important to know both the magnitude and the variability of the turgor pressure from cell to cell within a growing bacterial culture and how they change with physiological conditions.…”

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confidence: 99%

Nephelometric determination of turgor pressure in growing gram-negative bacteria

Koch¹,

Pinette²

1987

J Bacteriol

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Gas vesicles were used as probes to measure turgor pressure in Ancylobacter aquaticus. The externally applied pressure required to collapse the vesicles in turgid cells was compared with that in ceUs whose turgor had been partially or totally removed by adding an impermeable solute to the external medium. Since gram-negative bacteria do not have rigid cell walls, plasmolysis is not expected to occur in the same way as it does in the cells of higher plants. Bacterial cells shrink considerably before plasmolysis occurs in hyperosmotic media. The increase in pressure required to collapse 50% of the vesicles as external osmotic pressure increases is less than predicted from the degree of osmotically inducible shrinkage seen with this organism or with another gram-negative bacterium. This feature complicates the calculation of the turgor pressure as the difference between the collapse pressure of vesicles with and without sucrose present in thb medium. We propose a new model of the relationship between turgor pressure and the cell wall stress in gram-negative bacteria based on the behavior of an ideal elastic container when the pressure differential across its surface is decreased. We developed a new curve-fitting technique for evaluating bacterial turgor pressure measurements.

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Biochemical determination of bacterial morphology and the geometry of cell division

Cited by 57 publications

References 37 publications

Relative Rates of Surface and Volume Synthesis Set Bacterial Cell Size

Relative Rates of Surface and Volume Synthesis Set Bacterial Cell Size

Helical growth of Bacillus subtilis: a new model of cell growth.

Nephelometric determination of turgor pressure in growing gram-negative bacteria

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