Study of the Antibacterial Potency of Electroactivated Solutions of Calcium Lactate and Calcium Ascorbate on Bacillus cereus ATCC 14579 Vegetative Cells

Abstract

Bacillus cereus is a pathogenic bacterium, Gram-positive, aerobic, and facultative anaerobic that can produce spores and different toxins. It is involved in serious foodborne illnesses such as the diarrheal and emetic syndromes, depending on the ingested toxin. This work is aimed to study the potency of electroactivated solutions (EAS) of calcium lactate, calcium ascorbate, and their mixture as antibacterial agents against B. cereus ATCC 14579 vegetative cells. The solutions used were electroactivated under electric current intensities of 250, 500, and 750 mA for 30 min. The obtained EAS were tested in direct contact with B. cereus (107 CFU/mL) for different durations ranging from 5 s to 2 min. Moreover, standard lactic and ascorbic acids were tested as controls at equivalent titratable acidity as that of the corresponding electroactivated solutions. The obtained results showed that EAS exhibit high antibacterial efficacy against B. cereus vegetative cells. The EAS obtained after electroactivation of calcium lactate and calcium ascorbate were more efficient than those of their corresponding standard acids (lactic and ascorbic). The observed antibacterial effect of the EAS resulted in a reduction of 7 log CFU/mL after 5 s of direct contact in some specific cases. Scanning (SEM) and transmission (TEM) electron microscopic observations provided conclusive evidence of the antibacterial activity of the used EAS. These results outlined the highly antimicrobial potency of EAS against B. cereus vegetative cells and that they can be considered in an eventual strategy to ensure food safety, surface cleaning, as well as replacement of hazardous disinfecting chemicals.