Use of Pankhurst tubes to assay acetylene reduction by facultative and anaerobic nitrogen-fixing bacteria

Abstract

Pankhurst tubes are simple and inexpensive vessels in which to screen large numbers of bacterial isolates by the acetylene reduction test for nitrogen fixation. A modification is described which allows, in addition, optical density measurements of growth. The method is well suited to most probable number estimations of facultative and anaerobic nitrogen-fixing bacteria in soils and on root surfaces.