Oxygen responses of the free-living anaerobic amoeboflagellate Psalteriomonas lanterna

Abstract

The effects of O2 on growth of the anaerobic amoeboflagellate Psalteriomonas lanterna were studied. The organism tolerates low oxygen tensions (about 1% O2 atm. sat.) and under these conditions growth was stimulated in mixed populations. Catalase could not be found in the cells, whereas superoxide dismutase was present. Addition of O2 resulted in loss of the methanogenic endosymbionts and favoured the transformation to amoeba cells. Symbiont-free cells did not grow under anaerobic conditions probably due to the accumulation of H2. © 1992.