Biosynthetic requirements for the repair of sublethally injured Saccharomyces cerevisiae cells after pulsed electric fields.
OBJECTIVE
The aim was to evaluate the biosynthetic requirements for the repair of sublethal membrane damages in Saccharomyces cerevisiae cells after exposure to pulsed electric fields (PEF).


RESULTS
The partial loss of the integrity and functionality of the cytoplasmic membrane was assessed by adding sodium chloride to the recovery medium. More than 2 log(10) cycles of survivors were sublethally injured after PEF. Repair of sublethal membrane damages occurred when survivors to PEF were incubated in Sabouraud Broth for 4 h at room temperature. The addition of inhibitors, such as chloramphenicol, rifampicin, 5-fluorocytosine, nalidixic acid, cycloheximide, cerulenin, miconazol and sodium azide to the liquid repair medium showed that the repair of PEF-injured cells required energy and protein synthesis. The extent of the sublethal damages was greater in PEF-treated cells at pH 4.0 than at pH 7.0.


CONCLUSIONS
This work confirms that membrane damage is an important event in the PEF-inactivation of yeast. The mechanism of yeast inactivation by PEF seems to differ from that of bacteria, as the repair of sublethal damages requires protein synthesis.


CONCLUSIONS
Knowledge about the damages inflicted by PEF leads to a better description of the mechanism of yeast inactivation.
Somolinos
M
M
Departamento de Producción Animal y Ciencia de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain.
García
D
D
Condón
S
S
Mañas
P
P
Pagán
R
R
D002462:Cell Membrane / Q000378:metabolism; D003470:Culture Media; D004558:Electric Stimulation / Q000379:methods*; D005519:Food Preservation / Q000379:methods*; D009172:Mycology / Q000379:methods; D014176:Protein Biosynthesis; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000502:physiology
D003470:Culture Media