ULTRASTRUCTURAL LOCALIZATION OF TELLURITE REDUCTION IN ACHOLEPLASMA SPECIES

Abstract

Aerobic reduction of tellurite by 5 Acholeplasma spp. and 2 Mycoplasma spp. was investigated by light and EM. Among the Acholeplasma spp., colonies of A. laidlawii and A. oculi exhibited a heavy, macroscopically visible reduction of tellurite, but the reaction of A. axanthum was weaker. A. granularum and A. modicum did not reduce the substrate under the experimental conditions employed. The 2 subspecies of M. mycoides also reacted with tellurite, as did also the investigated strain of M. bovigenitalium although to a lesser extent. Ultrastructurally, reduction sites were localized to the cytoplasmic membrane in the 3 tellurite positive Acholeplasma spp. and apparently to the cytoplasm of M. mycoides ssp. mycoides. Reduction sites could not be demonstrated in M. mycoides ssp. capri and in M. bovigenitalium. These and other results indicate membrane localization of redox enzymes in Acholeplasma.