_____________________________________________________________________________ The effect of the acid and the osmotic stress on the heat resistance of Pseudomonas aeruginosa MC1 was studied at 63 oC in preparations at the base of cucumber, tomato and lettuce adjusted to various pHs (2, 3 and 4) or various NaCl concentrations (2, 4 and 6%). In the second study, the combined effect of pH and NaCl ...

The heat-shock 70 protein (Hsp70) chaperone family is very conserved and its prokaryotic homologue, the DnaK protein, is assumed to form one of the cellular systems for the prevention and restoration of heat-induced protein denaturation. By using anti-DnaK antibodies we purified the DnaK homologue heat-shock cognate protein (Hsc70) from calf thymus to apparent homogeneity. This protein was clas...

The onset of X-chromosome inactivation was investigated cytologically in postimplantation female mouse embryos of age 5£, 6\ and 1\ days post-coitum (d.p.c.) and in the isolated epiblasts of 6 d.p.c. embryos before primitive streak formation using a heat/hypotonic technique to reveal the inactive X chromosome by differentially dark staining with Giemsa. The results indicate that X inactivation ...

The question of a possible relationship between the RNA content of poliovirus and its reactivity as Nor H-antigen was examined with double-labeled virus preparations (32P-RNA, 14C-Protein). The following results were obtained: 1. Complete virus particles containing RNA may be Nor H-reactive. 2. Heat inactivation of poliovirus causes dissociation of capsid and RNA. 3. Under certain experimental ...

Pressure inactivation behavior of Bacillus amyloliquefaciens spores was investigated in deionized water. The spores of B. amyloliquefaciens were subjected to 105 degrees C and 700 MPa. The magnitude of the decrease in viability after pressure treatment was similar to that after pressure treatment followed by heat shock. The increase of dipicolinic acid (DPA) release was correlated with the spor...

Infectious pancreatic necrosis virus (IPNV) (serotype Sp) was exposed to temperatures between 60 and 90°C in a medium mimicking the water-soluble phase of hydrolyzed fish by-products. D values ranged from 290 to 0.5 min, and the z value was approximately 9.8°C. Addition of formic acid to create a pH 4 medium did not enhance heat inactivation. Predicted inactivation effects at different temperat...

Spores of Clostridium perfringens, type A, were given separate or sequential treatments of gamma radiation (0 to 0.7 Mrad) and/or high temperature (93 to 103 degrees C). Prior heating, sufficient to inactivate 40 to 99% of the viable spores, had no effect on the subsequent radiation inactivation rate. Prior irradiation had a sensitizing effect on subsequently heated spores. The degree of sensit...

Ultrasound in a liquid phase cause mass and heat transfer across the liquid through cavitational processes which act as nanoreactors to generate unstable mechanical equilibrium. The effect of 1 MHz ultrasound on the inactivation of Cryptosporidium parvum was investigated. Continuous irradiation of ultrasound (20 min) increased temperature due to cavitational phenomena. Ultrasound irradiation of...

The inactivation of thrombin by heat and by its physiological inhibitor, antithrombin-III, shows quite different dependence on heparin concentration. Heparin at 250 microgram/ml protects thrombin against heat inactivation, and thrombin behaves heterogeneously in this reaction. In the absence of heparin, the thermodynamic activation parameters change with temperature (deltaH+ = 733 kJ/mol and 21...

Virus inactivation by chemical disinfectants is an important instrument for infection control in medical settings, but the mechanisms involved are poorly understood. In this study, we systematically investigated the effects of several antiviral treatments on hepatitis C virus (HCV) particles as model for enveloped viruses. Studies were performed with authentic cell culture-derived viruses, and ...