[Isolation of an autotrophic variant of Nocardia opaca]

A hydrogen-oxidizing autotrophic actinomycete, strain Z-766, was isolated from the neuston of a marsh near Moscow. The organism was identified as Nocardia opaca Z-766 according to its morphologo-physiological properties. The spectrum of organic compounds used by the strain, its cultural characteristics and growth are similar to those of the monotypical autotrophic microorganism N. opaca 1b described earlier. Repeated isolation of the autotrophic variant of N. opaca Z-766 suggests that the ability of this species for autotrophic growth is not a unique phenomenon. It would be expedient to construct a taxon of the subspecial range, N. opaca var. autotrophica, for autotrophic variants of N. opaca.