Accession Number : ADA018892

Title :   The Physiological Bases for Microbial Barotolerance.

Descriptive Note : Annual technical rept. 31 Dec 74-31 Dec 75,


Personal Author(s) : Marquis,Robert E.

Report Date : 31 DEC 1975

Pagination or Media Count : 29

Abstract : The inhibition of streptococcal growth by hydrostatic pressure was found to be the result of an increased demand for adenosine triphosphate under pressure coupled with a somewhat diminshed supply. The increased demand seemed to be due to pressure stimulation of membrane adenosine triphosphatase. it was found also that pressure markedly upsets electrolyte balances in organisms such as Streptococcus faecalis but not in organisms such as Escherichia coli or Bacillus licheniformis. Data is presented in this report to suggest that one atmosphere is not the optimal growth pressure for many bacteria, but that growth at 100 atmospheres and a temperature slightly above the optimum is faster and more extensive than is growth at any temperature at one atmosphere. Data is presented also to show that bacterial growth under nonoptimal conditions is highly sensitive to pressure, and that at the low temperatures in natural aquatic environments, pressures as low as 50 atmospheres can have major inhibitory effects on growth of mesophilic or psychrotrophic bacteria. Finally, it was found that high-pressure oxygen stimulates synthesis and excretion of materials that absorb light of 260 nm wavelength and that the toxicity of oxygen may be related to derangements in nucleic acid metabolism. (Author)

Descriptors :   *Hydrostatic pressure, *Bacteria, *Growth(Physiology), Electrolytes(Physiology), Oxygen, Toxicity, Barometric pressure, Microbiology, Streptococcus, Adenosine phosphates, Low pressure, Potassium, Inhibition, Tolerances(Physiology), Escherichia coli, Reaction kinetics, Deep depth, Proteins, Metabolism, Magnesium, Hyperbaric conditions, Rare gases

Subject Categories : Stress Physiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE