MEMBRANE-ASSOCIATED POLYSACCHARIDES COMPOSITION, NUTRITIONAL-REQUIREMENTS AND CELL-DIFFERENTIATION IN HERPETOMONAS-ROITMANI - INFLUENCE OF THE ENDOSYMBIONT

Herpetomonas roitmani, a trypanosomatid containing a bacterial endosym biont, was cured by high doses of chloramphenicol. Wild-type and cured Bagatelles were compared as to polysaccharide composition, nutritiona l requirements and cellular differentiation. Fucose (18.0%), xylose (1 5.7%), mannose (38.9%), galactose (10.8%), glucose (16.4%) and inosito l (< 1.0%) were identified as polysaccharide components of cured H. ro itmani as assessed by gas-liquid chromatography. However, the wild-typ e strain displayed a markedly different sugar profile, in that xylose was absent and inositol preferentially synthesized, whereas the other monosaccharide components remained unchanged. Variations in nutritiona l pattern also occurred between both strains. The bacterial endosymbio nt seems to provide the flagellates with nutritional factors, includin g usual amino acids, vitamins, purine (as adenine) and hemin. The proc ess of cell differentiation was also significantly influenced by the e ndosymbiont. Opisthomastigote forms predominate (72.0%) in cured as co mpared with wild-type H. roitmani (37.0%).