A Study of Nitrogenase Activity in Mycoplana Species and Free-living Actinomycetes

Summary: A range of actinomycetes and Mycoplana strains were screened for nitrogenase activity. No positive results were obtained with actinomycetes, although some grew on media without added combined nitrogen. In contrast, most Mycoplana strains showed nitrogenase activity. Although the strains were unable to grow in anaerobic conditions, sustained nitrogen fixation required microaerobic conditions. The relationship of Mycoplana to actinomycetes is discussed.