Biotechnological implications of the interactions between magnesium and calcium

At the biochemical level, magnesium and calcium are known to act antagonistically towards each other. For example, many enzymes whose activities critically depend on sufficiency of intracellular magnesium, especially transphosphorylases, will be detrimentally affected by small increments in levels of cellular calcium ions. Growth of cells, cell division cycle progress and intermediary metabolism are also absolutely dependent on the bioavailability of magnesium, which can be compromised if excess calcium is present. Many biotechnological processes, therefore, which fundamentally exploit cellular growth and metabolism, will be influenced strongly by relative concentrations of the two cations and the ratio of bioavailable magnesium to calcium in external growth media. This paper surveys the interactive effects of magnesium and calcium at the bioinorganic level and discusses some examples of how these interactions may play important roles in governing the physiology of cells which are widely exploited in modern industrial bioprocesses.