Barotolerance is inducible by preincubation under hydrostatic pressure, cold-, osmotic- and acid-stress conditions in Lactobacillus sanfranciscensis DSM 20451T.
OBJECTIVE
This study addresses the inducibility of barotolerance by preincubation of Lactobacillus sanfranciscensis DSM 20451T under various sublethal stress conditions.


RESULTS
Stress conditions which reduce the growth rate of L. sanfranciscensis DSM 20451T to 10% of its maximum were determined. These conditions were met at 43, 12.5 degrees C, a pH value of 3.7, 1.9% NaCl, or 80 MPa respectively. In contrast to heat preincubation, other prestresses, including salt, cold and pressure led to an increase of barotolerance by hydrostatic pressure of 300 MPa for 30 min. Stationary-phase cells also showed an increased barotolerance. Sublethal pressure leads to enhanced heat tolerance.


CONCLUSIONS
Stress response to salt, low temperature and acidic pH as well as starvation overlap with that one to high pressure by inducing barotolerance.


CONCLUSIONS
Inactivation of bacteria by high pressure treatment is influenced by their history which modulates barotolerance. Mechanisms of barotolerance appear different from heat shock defence.
Scheyhing
C H
CH
Lehrstuhl für Technische Mikrobiologie, Freising, Germany.
Hörmann
S
S
Ehrmann
M A
MA
Vogel
R F
RF
D003080:Cold Temperature; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration; D006874:Hydrostatic Pressure; D007778:Lactobacillus / Q000254:growth & development* / Q000502:physiology; D009997:Osmotic Pressure