Accumulation and redox transformations of iron in the yeast Pichia guilliermondii and its flavinogenic mutants
Fedorovich, D.V.; Kityk, I.V.; Dzhala, V.I.; Protchenko, O.V.; Shavlovskii, G.M.
Mikrobiologiya 66(1): 60-64
The intracellular content of iron was studied in Pichia guilliermondii and its mutants with impaired regulation of riboflavin synthesis and iron transport into cells (rib80, rib81, rib80 rib81, and hit). The intracellular content of iron depended on its concentration in the medium and the phase of culture growth. The cells of mutants rib80 and hit, but not of rib81, accumulated 3-4 times more iron than wild cells. Wild cells accumulated iron mainly in the form of Fe(II), and mutant cells, in the form of Fe(III), as revealed by Mossbauer and EPR spectroscopic studies. Iron in cells of mutant rib80 did not enter into ferritin; instead a low-molecular iron-binding compound was isolated and partially purified from cell-free extract of this mutant.