Effects of Hydrostatic Pressure and Temperature on the Uptake and Respiration of Amino Acids by a Facultatively Psychrophilic Marine Bacterium

Abstract

Studies of pressure and temperature effects on glutamic acid transport and utilization indicated that hydrostatic pressure and low temperature inhibit glutamate transport more than glutamate respiration. The effects of pressure on transport were reduced at temperatures near the optimum. Similar results were obtained for glycine, phenylalanine, and proline. Pressure effects on the transport systems of all four amino acids were reversible to some degree. Both proline and glutamic acid were able to protect their transport proteins against pressure damage. The data presented indicate that the uptake of amino acids by cells under pressure is inhibited, which is the cause of their inability to grow under pressure.

Effect of high pressure and pasteurization on Mycobacterium avium ssp. paratuberculosis in milk

“…This, it was considered, would nullify, to some extent, effects of the clumping phenomenon and make all Map cells equally susceptible to such a process. It was also hoped that as high pressures exert their effect principally on the cytoplasmic membranes of bacteria (Paul and Morita 1971) any contribution to resistance imposed by the thick hydrophobic cell wall of Map would also be reduced.…”

Psychrophilic bacteria.

“…Pressure was found to inhibit the transport of amino acids into a psychrotrophic bacterium (150). Once the amino acids are transported into the cells, the respiratory mechanism needed to produce carbon dioxide from the amino acids does not appear to be inhibited.…”

“…When the temperature is lowered below the optimal growth temperature, the uptake of substrates is decreased (9,92,128,150,152).…”

High hydrostatic pressure extraction of flavonoids from propolis

“…High hydrostatic pressure means cold isostatic superhigh hydraulic pressure that ranges from 100MPa to 800MPa or more. High hydrostatic pressure can cause some structural changes in structurally‐fragile foods, such as cell deformation, cell membrane damage, protein denaturation12–14 and so on. Based on the phase behavior theory, the solubility is greater as the pressure increases 15, 16.…”

“…There have some reports about extraction of flavonoids from propolis,11–22 such as extraction at room temperature, heat reflux extraction, etc. However, there no reports have been on the use of HHPE for the extraction of flavonoids from propolis.…”