Accession Number : AD0771469

Title :   The Physiological Bases for Microbial Barotolerance.

Descriptive Note : Technical rept. (Annual) no. 2, 1 Jun-31 Dec 73,


Personal Author(s) : Marquis,Robert E.

Report Date : 29 DEC 1973

Pagination or Media Count : 40

Abstract : Results of experiments to define the ways in which pressure and temperature interact to affect growth of psychrophilic, mesophilic and thermophilic bacteria indicated that barotolerance is greatest at optimal growth temperatures. Below the optimum, pressure and temperature acted antagonistically; while at higher temperatures, they generally acted synergistically to restrict growth. Other experimental results indicated that pressure markedly narrows pH ranges for bacterial growth and, at extreme pH, causes leakage of potassium ions from cells without also causing massive RNA breakdown. The adverse effects of low, but not high, pH under pressure could be partially reversed with divalent cations. It was found also that part of the basis for low growth yields commonly obtained with pressurized cultures is the enhanced sensitivity to metabolic acids that build up in enclosed pressure vessels during growth. (Modified author abstract)

Descriptors :   *Bacteria, *Pressure, Growth(Physiology), Temperature, Barometric pressure, Physiology, Tolerances(Physiology), pH factor, Experimental data

Subject Categories : Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE