Effects of Ca2+ and Mg2+ on the Biofilm Formation of Cronobacter Sakazakii Strains from Powdered Infant Formula

Biofilm of Cronobacter sakazakii on food contact surfaces is the important source of persistent contamination in powdered infant formula. This study aimed to assess the effects of Ca2+ and Mg2+ on biofilm formation. Results indicated that the biofilm-forming ability was strain specific and divalent cation concentrations dependent. Most of C. sakazakii formed the highest amount of biomass at 1.50% MgCl2 (17 strains, 74%) and 0.25% CaCl2 (10 strains, 43.4%)(.) Finally, confocal laser scanning microscope (CLSM) further indicated that effects of divalent cation were attributable to changing properties of extracellular matrix. The findings presented here provide new insights for control of biofilm formation in dairy products. Practical ApplicationsC.sakazakii is an important foodborne pathogen involved in infections of infant. Control of C. sakazakii contamination in powdered infant formula is an intractable problem in production of powdered infant formula. In this study, effects of Ca2+ and Mg2+ on the biofilm formation were performed. Furthermore, the changes of extracellular matrix in biofilm were revealed by CLSM. The results contribute to useful information for development of essential measures for precaution and control of biofilm of C. sakazakii.