Development of defined media for motility and for growth of Spirillum volutans, with special reference to biological monitoring of pollutants and to obligate microaerophilism of bacteria

Two investigations were pursued in this study. One was a possible application of the motility of Spirillum volutans to detection of pollutants in industrial effluent for the purpose of in-plant biological monitoring. The other was a nutritional study of the organism with emphasis on its obligate microaerophilism.

In the pollution monitoring project, flagellar uncoordination in S. volutans was studied as a bioindicator of toxicity. Uncoordination is produced by a variety of agents. Cells displaying normal motility show frequent reversal of direction, accompanied by reversal of orientation of their bipolar fascicles of flagella. In uncoordinated cells, the flagella at opposite poles oppose each other and the cell cannot swim, although the flagella remain active.

A defined motility test medium was devised in an attempt to maximize the sensitivity of the uncoordination response to potential pollutants. Suspensions of S. volutans in this medium responded to a variety of agents, including metal ions (1-3 ppm), cetyl pyridinium chloride (1 ppm), hydrazine (10 ppm), i-naphthol (3 ppm), and others. Effective concentrations ranged up to several per cent for the alcohols tested. The response was immediate.