The Genera Spirillum, Aquaspirillum, and Oceanospirillum

Abstract

The organisms in the genera Spirillum, Aquaspirillum, and Oceanospirillum share a number of typical characteristics, the most distinctive of which are: (i) a curved and twisted shape, either vibrioid (less than one complete turn) or helical (one or more helical turns); (ii) a characteristic rotating corkscrew type of motility, with rapid swimming back and forth in straight lines; (iii) occurrence of polar flagella, usually bipolar tufts; and (iv) a strictly respiratory type of metabolism, with oxygen and occasionally nitrate serving as the terminal electron acceptors. The organisms occur as harmless saprophytes in freshwater or marine environments, but do not predominate in these environments. They are Gram negative, chemoheterotrophic, give a positive oxidase reaction, and usually contain intracellular poly-$β$-hydroxybutyrate (PHB). The best carbon sources for growth are salts of organic acids; amino acids are also satisfactory.