Effect of Viscosity on Bacterial Motility

Abstract

The behavior of a number of motile flagellated bacteria toward viscosity characteristics of their fluid environments was observed. All showed an increase in velocity (micrometers per second) in more viscous solutions. Velocity reached a maximum at a characteristic value, however, and thereafter decreased with higher viscosities. Peritrichously flagellated bacteria had maximum velocities at higher viscosities than polarly flagellated bacteria. Effects of temperature, and possible utilization of chemical constituents in the viscous solutions, were studied and found to be negligible factors under the experimental conditions used. Different agents produced the same phenomenon, thus indicating that there probably were no chemically induced metabolic effects. Loss of available water and the possibility of a variable energy supply to the flagellar propulsive system were considered but are believed minimal. Theoretically derived thermodynamic equations were utilized and suggest that the conformation of the flagellar helix affects efficiency of propulsion. Such a relationship between helix waveform and velocity was experimentally observed with Thiospirillum jenese .

Motility, behavior, and aggregation of Sporosarcina ureae

“…The effects of viscosity on movement, and flagellar regeneration times were similar to those reported for cylindrical organisms [8,9]. Aggregation via flagella-flagella contact has been observed with Pseudomonas marina [10].…”

Response of populations of human faecal bacteria to viscosity in vitro

“…The effect of viscosity on the bacterial populations in the colonic lumen seems not to have been previously considered, although it has been reported (Schneider & Doetsch 1974;Greenberg & Canale-Parola 1977) that viscosity modified the motility of several organisms and, in some cases (Petrino & Doetsch 1978), a positive response to a viscosity gradient ('viscotaxis') was seen. Effects of viscosity on the activity of bacterial and digestive enzymes have also been noted (Ceska 1971;Isaksson ec al.…”

Viscosity has dichotomous effects onBdellovibrio bacteriovorusHD100 predation

“…As an alternative, they suggested low-molecular-weight impurities present in the polymers are responsible as dialyzing the solutions eliminated this phenomenon, i.e., faster bacterial motility. Nevertheless, their explanation does not address the difference seen between linear and branched polymers as enhanced motilities are observed in linear polymer solutions (Shoesmith, 1960;Schneider and Doetsch, 1974 ;Greenberg and Canale-Parola, 1977 ;Ferrero and Lee, 1988) but not in branched polymers solutions, such as DEX or Ficoll (Shoesmith, 1960;Berg and Turner, 1979). Still other groups proposed slight increases in the media viscosity enhance the sheer force generated by the flagella, producing a better forward vector force than in water alone (Schneider and Doetsch, 1974;Greenberg and Canale-Parola, 1977;Ferrero and Lee, 1988).…”

“…It is known that linear polymers, such as PEG, impact the swimming speeds of various microorganisms (Shoesmith, 1960;Schneider and Doetsch, 1974;Greenberg and Canale-Parola, 1977;Ferrero and Lee, 1988). Consequently, we measured the swimming rates for B. bacteriovorus HD100 in the PEG solutions ( Fig.…”