Ethanol and NaCl susceptibility and protein expression of acid-adapted B. cereus 1-4-1 as well as its growth patterns in the presence of various carbon and nitrogen sources.

Abstract In the present study, the foodborne pathogen Bacillus cereus 1-4-1 was subjected to acid adaptation treatment by suspending the test organism in tryptic soy broth (pH 5.5) for 2 hours. The susceptibility of the acid-adapted and nonadapted cells of B. cereus 1-4-1 to high concentrations of ethanol (20%) and NaCl (20%) was then examined. In addition, the effect of acid adaptation on the protein expression profile of B. cereus 1-4-1 as well as the growth patterns of the acid-adapted and nonadapted cells of the test organism in the presence of various carbon and nitrogen sources were compared. Results revealed that acid-adapted B. cereus 1-4-1 was more susceptible to ethanol (20%) and NaCl (20%) than its nonadapted counterpart. Analysis with one-dimensional SDS-PAGE showed no distinct difference in the expression of the 16 proteins bands noted in the nonadapted cells compared with those of acid-adapted cells. Two-dimensional electrophoresis revealed that the acid adaptation treatment affected the exp...