Effects of metals on microorganisms in the environment

Life depends on interactions between organic and inorganic components. The organic building blocks of life consist of nucleic acids, proteins, carbohydrates, and lipids; however, many of these organic compounds require inorganic metals to function properly. Metals that have a biological function, such as copper, nickel, magnesium, manganese, and zinc, are deemed essential metals.¹ These metals commonly serve as cofactors for proteinaceous enzymes, but they may also be used to stabilize proteins and bacterial cell walls.^1-3 Enzymatic function is reliant on a specific threedimensional structure. A change in a single amino acid may alter the shape of an active site, leading to inactivation of the enzyme. Metal cofactors also act by affecting the folding patterns of enzymes. A positively charged metal ion may have specific interactions with negatively charged amino acids, such as aspartic and glutamic acid residues. The interaction between metal ions and amino acids is sufficient to alter the entire structure, and therefore function, of an enzyme.