Initiation of Germination of Bacterial Spores by Hydrostatic Pressure

Abstract

S U M M A R YHydrostatic pressure initiated germination of bacterial spores in nutrientfree media. Those spores which were most dormant towards chemical germinants at I atmosphere pressure were also the most resistant to germination by pressure treatment. Germination by high pressure treatment was characterized by temperature and pH optima, like germination at atmospheric pressure. Germination initiated by pressure was inhibited by metabolic poisons and was potentiated by low concentrations of various nutrients including some of those which are normally germinative (at higher concentrations) at atmospheric pressure. In particular, L-alanine and closely related a-amino acids, but not their breakdown products, potentiated germination initiated by pressure. Study of potentiation by D-alanine (which strongly inhibits germination initiated by L-alanine at I atmosphere pressure) revealed that high pressures caused an increase in the rate of racemization of alanine by spores. Germination by pressure probably resulted from acceleration of some germination reaction which is normally negligibly slow at a pressure of I atmosphere, and also from an increase in permeability of some barrier within the spore to L-alanine and related a-amino acids.

Germination of Spores of Clostridium bifermentans by Certain Amino Acids, Lactate and Pyruvate in the Presence of Sodium or Potassium Ions

“…This alleviation of the specific requirements for germination was also apparent with regard to the requirement for inorganic ions. Alleviation of specific requirements for amino acids has been observed with Bacillus cereus in the presence of inosine or at high atmospheric pressures (Gould & Sale, 1970) and with B. megaterium after heating (Levinson & Hyatt, I 962). However, as germination of Bacillus spores can usually be initiated by any one of several amino acids, the germinative properties of mixtures of amino acids have been little studied, although in the presence of L-alanine there was no stimulation of the germination rate of B. subtilis var.…”

Exploration of the Effects of High Hydrostatic Pressure on Microbial Growth, Physiology and Survival: Perspectives from Piezophysiology

“…48) Pressures of 100-300 MPa activate the nutrient receptors whereas higher pressures of 500-800 MPa release the Ca 2þ -DPA depot. 46,49,50) The results of these studies give new insight into the mechanism of spore germination as well as contributions to food processing technology by high-pressure treatment. Table 2 lists the occurrence of yeast physiology and survival under high hydrostatic pressure.…”

“…45) Spores of Bacillus species are germinated by a variety of stimuli including nutrients, some chemicals and mechanical treatments such as abrasion and high pressure. [46][47][48] Nutrients trigger the receptors GerA, GerB and GerK in the inner membrane of the spore, followed by release of the Ca 2þ -dipicolinic acid (DPA) depot and activation of enzymes CwlJ and SleB. 48) Pressures of 100-300 MPa activate the nutrient receptors whereas higher pressures of 500-800 MPa release the Ca 2þ -DPA depot.…”

Alpha‐Hydroxy Acids as Co‐Germinants for Some Clostridial Spores

“…As for the synergism of ribosides with amino acids as germinants for Bacillus spores, Gould and Sale [6], from their study on the germinant action of hydrostatic pressure, have suggested that both riboside and pressure may function to increase the spore permeability to exogenous or endgenous a-amino acids. In this connection, Kaback and Milner [8] recently …”