Exploitation of N₂-fixation capacity for enrichment of anoxygenic photosynthetic bacteria in ecological studies

Abstract

A procedure is described for the selective enrichment of anoxygenic photosynthetic bacteria from diverse natural sources containing numerous types of microorganisms. The enrichment medium contains a mixture of organic acid carbon sources, and the conditions used favor the growth of organisms that can multiply relatively rapidly anaerobically with N2 as the nitrogen source and light as the source of growth energy; the development of oxygenic cyanobacteria is effectively excluded.