mass of bacteria

Larry Farrell farrlarr at
Mon Apr 8 09:51:39 EST 2002

Nicholas Landau wrote:

> For what it is worth, Neidhardt et al. do list a figure for the dry weight of a
> single E. coli cell in their microbial physiology text."  The figure they list
> is 2.9 E-13 g.  The do not include any citations for this figure specifically,
> but they do state that it is "an average of many measurements..."  Neidhardt,
> F.C., J. L. Ingraham, and M. Schaecher.  1990.  Physiology of the Bacterial
> Cell.  Sunderland, Mass: Sinauer Associates.

Please note, however, that this is a dry weight and at least half of the weight of
the cell would be water.  Therefore, this weight must be multiplied by at least

> Would you like the mailing address for that egg?
> Incidentally, who said that the largest viruses are larger than the smallest
> bacteria?  I have to admit, I know little about viruses, but I can hardly
> believe that statement is true.  What virus is as large as a bacterium?

Some of the cocci (bacteria) are as small as 0.2 micrometer in diameter, while
smallpox is 0.2-0.3 micrometer x 0.25 micrometer.
Larry D. Farrell, Ph.D.
Professor of Microbiology
Idaho State University

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