Green olives may be preserved in brine, which is a 20-30% salt solution. how does this method prevent contamination by microorganisms? green olives may be preserved in brine, which is a 20-30% salt solution. how does this method prevent contamination by microorganisms? high salt concentrations raise the ph, thus inhibiting the process of glycolysis. bacteria can't survive in a hypertonic solution because they lose water. high salt concentrations lower the ph, thus inhibiting the process of glycolysis. bacterial cell walls are shriveled up by salt, causing the cell to burst.