Ultrastructural and cytochemical study of Rhodotorula glutinis in the main growth phases

The aerobic, carotenogenic yeast Rhodotorula glutinis accumulates different storage materials in the main phases of growth.Exponentially growing cells store glycogen principally in two polls: cytoplasmic and vacuolar granules. At the ultrastructural level, the polymer was detected by specific cytochemical reactions. In the subsequent retardation and stationary phases of growth, the micro-organism accumulates, instead, large quantities of lipids.During the shift from the exponential phase to the stationary one, some changes in the wall architecture were also evident. Interpretations justifying the observed cytological changes are proposed.This work was supported by a grant from the Italian Research Council (CNR) N 81.00177.04.