Efecto del tratamiento por ultrasonidos sobre la termorresitencia de los esporos de Bacillus Cereus y Bacillus Licheniformis

Abstract

Heat resistance of Bacillus cereus and Bacillus licheniformis spores in Ringer solution 1 / 4 greatly decreases after ultrasonic treatments unable to kill a significant proportion of the spore population. Spores of B. cereus are more easily heat sensitized by ultrasonics than B. licheniofrmis.D₁₁₀ºc. of B. cereus can be reduced from 11,5 to 1,5 min. by 1,5 min. of ultrasonication at a frequence of 20 Kc. D₉₉ºC. of B. licheniformis decreases from 5.,5 to 3 min. after 10 min. of ultrasonication. These findings may have very interesting practical aplications in food sterilization and rules out the use of ultrasonics to free of vegetative cells or to break agregates in spore suspensions to be used in heat resistance experiments.