Sulfur is needed for some amino acids (cysteine and methionine). It is also found in some vitamins (biotin, thiamine, lipoic acid). It is also needed for Coenzyme A.
Potassium is used by enzymes in protein synthesis. All living things require potassium.
Magnesium is needed to help ribosomes remain intact. Ribosomes are organelles that make protein.
Calcium protects cell walls and is necessary for heat stability in some microorganisms.
Sodium is required for growth of some marine (ocean) microorganisms.