Morphogenic effect of 2-deoxy-D-arabino-hexose on Rhodosporidium toruloides

The presence of 2-deoxy-D-arabino-hexose in the growth medium caused marked morphological changes in the cells of Rhodosporidium toruloides. The originally elongated ellipsoidal cells grew spherically in the presence of the deoxy-sugar, displayed differences in cell division and separation, and were larger than the control cells. After exhaustion of glucose from the medium the cells died, although no lysis was observed. The morphological changes were accompanied by significant alterations in the carbohydrate composition of the cell wall. The wall of R. toruloides grown in the presence of the deoxy-sugar contains higher proportions of chitin and glucan, while the relative contents of mannose and galactose polymers decreased drastically in comparison to normal cells.