Enrichment of milk with magnesium provides healthier and safer dairy products

Antimicrobial effect of Mg2+ ions on Bacillus species during growth within milk. a The effect of Mg2+ ions on biofilm bundles formation by fluorescently tagged B. subtilis strains of the wild type (WT), the ΔabrB mutant, and the ΔsinR mutant. Bacterial cells were grown in milk with or without addition of MgCl2, and then were analyzed using confocal microscope. b The effect of Mg2+ ions on transcription of tapA operon that is responsible for the matrix production in B. subtilis. The WT cells harboring PtapA-cfp transcriptional fusion were grown overnight in milk with or without addition of MgCl2 and analyzed using confocal microscope. c The survival rate of B. subtilis under heat treatment within milk in the presence of Mg2+ ions. Bacterial cells grown in milk (with or without addition of MgCl2), were subjected to heat treatment (performed at 63？°C for 3？min) and the survival rate was determined using the CFU method. d The effect of Mg2+ ions on biofilm formation by different Bacillus species known to contaminate milk. The cells of B. cereus ATCC 10987 and B. licheniformis MS310 in milk (with or without addition of MgCl2) were stained with the LIVE/DEAD viability kit and analyzed using confocal microscope. Scale bar—20？μm. *P-value？<？0.05 for comparison with control unsupplemented milk. Error bars represent standard deviation (SD