These bacteria are referred to as nitrogen-fixing bacteria . Phosphorous Phosphorous found in nucleotides and phospholipids. Phosphorous occurs in nature as organic or inorganic as phosphates forms. Sulfur Sulfur found in specific amino acids and vitamins. Sulfur occurs in nature as organic or inorganic forms.
Bacteria use sulfate or sulfide forms.
Required in smaller amounts Potassium Required as a cofactor for a number of enzymes. Magnesium Required to stabilize ribosomes, cell membranes, nucleic acids and required by a number of enzymes. Calcium Stabilizes cell wall and important for heat stability of spores. Sodium Required by some but not all microorganisms. Usually seawater organisms have a requirement but freshwater or terrestrial organisms do not.