PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 404390

A simple quantitative assay for bacterial motility.

L A Segel·I Chet·Y Henis
View original source ↗Export metadata ↓

Abstract

It is argued that the average motility of bacterial populations should be identified with a diffusivity parameter. A simple capillary assay for quantifying this parameter is described, and some results obtained by using this procedure are presented. It is concluded that the assay combine speed and simplicity of operation with sufficient accuracy to make it a valuable tool in the assessment of motility.

Explore related subjects

Bacterial Physiological PhenomenaMethodsMovementPseudomonas fluorescensTime FactorsJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L A Segel, I Chet, Y Henis. 1977. A simple quantitative assay for bacterial motility.. https://doi.org/10.1099/00221287-98-2-329

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Rapid assessment of bacterial viability by flow cytometry.

The ability of a flow cytometer to rapidly assess microbial viability was investigated using three vital stains: rhodamine 123 (Rh123); 3,3'-dihexyloxacarbocyanine iodide [DiOC6(3)] and fluorescein diacetate (FDA). Rh123 was found to clearly differentiate viable from non-viable bacteria. The methodology for staining bacteria with this dye was optimised. Rh123 was shown to stain and discriminate several different species of viable bacteria although this was not universal. Viable cells of Bacillus subtilis were found to stain better with FDA than with Rh123. The results demonstrate the ability of flow cytometry to rapidly detect and estimate the viability of bacterial populations.

Bacterial Physiological Phenomena↗
PubMed1992

Bacterial motility and chemotaxis.

Bacteria swim using the only rotary motor identified in biology. The membrane bound motor uses the gradient of protons set up across the cytoplasmic membrane to drive the rotation of a semi-rigid protein helix, the flagellum. Free-swimming bacteria randomly change direction every few seconds, but if a gradient is encountered the direction-changing frequency can be biased to move the bacterium in a favourable direction. Bacteria respond to changes in chemical concentration, oxygen levels, pH, the intensity or wavelength of light, temperature and in some cases even the Earth's magnetic field and integrate the signals to move towards or maintain the cells in optimum conditions for growth and division. They also adapt to the changes, leaving them free to respond to any subsequent stimuli. Therefore bacteria have something akin to a primitive nervous system, with a sensory system which can respond and adapt to changes and integrate physical and chemical signals. Chemotaxis and motility are involved in infection, both positive (rhizobia) and negative (pathogens) and an understanding of the unique nature of motility and chemotaxis in bacteria may make it possible to control infection. This review will give a brief general overview of current knowledge of bacterial motility and chemotaxis but for more detailed analysis readers are referred to some more specific recent reviews.

Bacterial Physiological Phenomena↗