Cyanide resistance and cyanide utilization by a strain of Bacillus pumilus

Abstract

A strain of Bacillus pumilus was isolated from Fargo clay in a field near Fargo, North Dakota, which had been cropped in flax 73 consecutive years. This bacterium had an unusual ability to survive saturated solutions of potassium cyanide. The optimal growth conditions of this strain of Bacillus pumilus in the standard medium with 10−1 M cyanide as well as its morphological changes to a filamentous form under the influence of cyanide were established. Both 14CO2 and 15NH4+ were produced in cultures of the organism during labelling experiments in which K14C15N was fed, supporting the idea of cyanide utilization by this bacterium. Oxygen uptake studies by the filamentous form in the presence of 10−1 M KCN suggested that it has an extreme tolerance to cyanide. This is the first report of a bacterium being able to survive solutions of KCN up to 2.5 M.