This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Novotny, C. Articles by Brinton, C. C. Search for Related Content PubMed PubMed Citation Articles by Novotny, C. Articles by Brinton, C. C., Jr.

 Previous Article  |  Next Article 

J Bacteriol. 1969 June; 98(3): 1294-1306
Copyright © 1969 American Society for Microbiology. All Rights Reserved.

Mechanical Removal of F Pili, Type I Pili, and Flagella from Hfr and RTF Donor Cells and the Kinetics of Their Reappearance

^a Department of Biophysics and Microbiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213

ABSTRACT

The effect of mechanical agitation (blending) on the removal of F pili, type I pili, and flagella from Hfr (high-frequency recombinant) and resistance transfer factor (RTF) fi⁺Escherichia coli cells was studied by electron microscopy. The reduction in number and length of appendages was measured as a function of blendor speed under standard conditions of temperature, medium, cell density, and blendor configuration. F pili and flagella were removed within the same narrow range of blendor speeds. Type I pili were removed within a higher and broader range of speeds. The speed which reduced the average length of type I pili to 50% was 3.5 times the speed which reduced the average length of F pili to 50%. None of the speeds employed inhibited cell growth, viability, or the ability to produce cell appendages. The kinetics of reappearance of F pili and type I pili after removal by blending were also different. F pili grew out very rapidly, reaching 50% of their full length in 30 sec and their full length in 4 to 5 min. The number of attached F pili per cell also increased rapidly, reaching a constant value in 4 to 5 min. After 5 min, F pilus lengths were distributed around a modal value of about 1.2 µm, and the numbers of F pili per cell were distributed according to a Poisson distribution, with an average of 1.0 per cell. These reappearance kinetics, length distributions, and number distributions are consistent with a model of F-pilus outgrowth in which new F pili appear at random locations on the cell surface at an average rate of about once every 4 min, grow to their characteristic length in about 4 min, and then separate from the cell. F pili which had separated could absorb to the cells, leading to the presence of two classes of F pili on cells: those in the process of natural out-growth and those attached by absorption. Type I pili increased in length much more slowly than did F pili, although the fraction of cells having visible type I pili increased very rapidly after blending because of the large number of type I pili per cell. The fraction of flagellated cells increased even more slowly, reaching only 30% of the unblended fraction in 30 min. The application of blending spectra and reappearance kinetics to the identification of cell functions with surface structures is discussed.

¹ Present address: Department of Medical Microbiology, College of Medicine, University of Vermont, Burlington, Vt. 05401.

This article has been cited by other articles:

• Sherburne, C. K., Lawley, T. D., Gilmour, M. W., Blattner, F. R., Burland, V., Grotbeck, E., Rose, D. J., Taylor, D. E. (2000). The complete DNA sequence and analysis of R27, a large IncHI plasmid from Salmonella typhi that is temperature sensitive for transfer. Nucleic Acids Res 28: 2177-2186 [Abstract] [Full Text]