Kj. Clarke et al., CYCLIDIUM-PORCATUM NSP - A FREE-LIVING ANAEROBIC SCUTICOCILIATE CONTAINING A STABLE COMPLEX OF HYDROGENOSOMES, EUBACTERIA AND ARCHAEOBACTERIA, European journal of protistology, 29(2), 1993, pp. 262-270
A new ciliate species (Cyclidium porcatum) is the first freshwater ana
erobic scuticociliate to be cultured and described. It contains a uniq
ue tripartite structure consisting of hydrogenosomes (confirmed by cyt
ochemical staining for hydrogenase), interspersed with methanogens (co
nfirmed by autofluorescence and in situ hybridisation with an archaeob
acterial 16S rRNA-specific probe) and unidentified eubacteria (confirm
ed with a eubacterial 16S rRNA-specific probe). This complex structure
is stable and persistent, indicating that it is an anaerobic symbioti
c consortium incorporating three functional partners.