Biochemical and ultrastructural changes in Herpetomonas roitmani related to the energy metabolism

Herpetomonas roitmani, a non-pathogenic trypanosomatid was grown in chemically defined media either containing proline or glucose as carbon source. Using transmission electron microscopy we observed that cells grown in the presence of proline present more lipid inclusions, and a larger mitochondrion with more cristae and higher activity of succinate cytochrome c reductase. On the other hand, cells grown with glucose as carbon source had more glycosomes, which were preferentially located close to the bacterium endosymbiont, and a much higher activity of hexokinase, a typical glycosome marker. Three-dimensional reconstruction and morphometrical analysis confirm these observations. The number of promastigotes of H. roitmani increased in the presence of proline. Taken together these results indicate that the growth conditions markedly influenced the ultrastructure and the metabolism of H. roitmani.