The Isolation of Nitrosomonas europaea in Pure Culture

SUMMARY: Nitrosomonas europaea (Winogradsky) was isolated in pure culture from Rothamsted soil. The method used entailed: (1) building up the population of nitrifiers in enrichment cultures; (2) removal of the cells from the chalk in an enriched culture with a stream of carbon dioxide; (3) picking colonies from poured silica gel plates.