Magnesium is an essential requirement for the growth
of Schizosaccharomyces pombe when grown in batch culture
conditions. It is taken up by the yeast cells during
growth with some fluctuations in the amount required at
different phases of the growth cycle. Magnesium uptake per
cell was greatest when the initial inoculum level was low.
Magnesium limitation reduced the fermentative capacity of
S . pombe and enhanced respiration under aerobic conditions.
Oxygen uptake was also increased under Mg - limited
conditions reflecting a release from catabolite repression.
In the yeast Saccharomyces cerevisiae, calcium had no
effect on growth rate, unlike magnesium which reduced the
amount of growth dramatically. This indicated an essential
role for magnesium and the non essential role of calcium in
this yeast species. Magnesium limitation also altered the
morphology of this yeast to a more enlarged form and
inhibited cell division and budding.
The growth of S . pombe was also shown to be directly
affected by the availability of magnesium. When grown in a
magnesium limited chemostat, an increase in cell volume was
accompanied by an increase in intracellular magnesium.
Also, at low growth rates, fermentation was reduced
compared to that occurring at higher growth rates.