An electron microscopic study of the phosphatases in the ciliate Balantidium coli.

The localisation and activity of D glucose-6-phosphatase (G-6-Pase) and alkaline phosphatase (AlP) in the trophozoites of Balantidium coli isolated from pig intestine content were investigated using ultrastructural and cytochemical methods. The activity of G-6-Pase was demonstrated on the membranes of the endoplasmic reticulum, particularly in the cortical part of the trophozoites. In addition, the product of the reaction to G-6-Pase was concentrated in the vesicular structures, which were distributed along the reticular membranes. These structures were described as vesicles similar to glycosomes, containing enzymes of glycogenolysis. It is very likely that hydrolases in B. coli are formed on the rough reticular membranes without the involvement of cisterns of the Golgi complex. The ultrastructural deposits of the reaction to G-6-Pase and AlP in the trophozoites of B. coli described here indicate that some membranes of the rough endoplasmic reticulum and small vacuoles with a strong reaction to these enzymes can play a similar role to the Golgi complex.

The formation of primary and secondary lysosomes in Balantidium coli, Ciliata.

Trophozoites, vegetative forms of Balantidum coli isolated from pigs affected by acute and asymptomatic balantidiasis were studied. Lysosomes and food vacuoles were revealed by cytochemical detection of lysosomal marker, acid phosphatase. The cytoplasm of all the B. coli trophozoites examined was found to contain numerous structures which differed widely in shape, size and location in the cells. One of them was located among the rough endoplasmic reticulum membranes and another one in the vicinity of endosomes. Those structures were regarded as the primary lysosomes. The two types of vesicular structures most probably represent two stages of the primary lysosome formation. Trophozoites were also found to contain secondary lysosomes which are formed by fusion of several primary lysosomes with phagosomes. The ultrathin sections of B. coli trohozoites showed the presence of two types of phagosomes. They were divided, based on their contents, into auto- and heterophagosomes.

Cytochemical identification of mucocysts in Balantidium coli trophozoites.

The mucocyst ultrastructure in B. coli has not been described so far. As demonstrated in this work, cytoenzymatic assays on B. coli with the use of a reaction-detecting membrane-coupled hydrolase, i.e., ATP-ase, permitted identification of the mucocysts in the ciliate studied. The shape, size, and location of mucocysts in B. coli trophozoites were found to correspond to descriptions of these structures in other ciliates. The mucocysts were more numerous in B. coli trophozoites isolated from the symptomatic balantidiosis-affected pigs (Group I), and the product of reaction to ATP-ase was more copious than in Group II trophozoites. However, not all the bubble-like structures with similar morphological features reacted positively to the enzyme. The discrepancy was explained by the cytoenzymatic reaction to Beta-GR. The reaction product was visible in the vesicular structures, situated above the plasmolemma, although some of them contained no reaction product. Thus the presence of two types of secretory structure can be inferred: the mucocysts, with ATP-ase in their membranes, and other extrusomes containing active Beta-GR.