Induction of the synthesis of cell wall alpha-1,3-glucan in the yeastlike form of Paracoccidioides brasiliensis strain IVIC Pb9 by fetal calf serum.

In vitro subculturing of the yeastlike form of Paracoccidioides brasiliensis strain IVIC Pb9 leads to the disappearance of alpha-1,3-glucan as a main component of its cell wall. However, the addition of fetal calf serum to the growth medium induces the synthesis of this polysaccharide. It is suggested that the synthesis of alpha-1,3-glucan in the cell wall of the yeastlike form of P. brasiliensis is induced by external factors.