Page:Bergey's manual of determinative bacteriology.djvu/236

 or glycerol not utilized. Ammonium sulfate ander, Minnesota, and other fresh-water or casamino acids used as sources of nitro- lakes (Henrici and Johnson, op. cit., 30, gen; ammonium nitrate not utilized. 1935, 83). Also found in well-water in Ken- Optimum temperature, 30° C. tucky (Bowers et al., op. cit.). Aerobic, facultative. Habitat: Water, where it grows upon firm Source: Found frequently in Lake Alex- substrates.

Gal.li.o.nel'la. Named for Benjamin Gaillon, receiver of customs and zoologist (1782-1839) in Dieppe, France; M.L. dim. ending -ella; M.L. fem.n. Gallionella a generic name.

Cells kidney-shaped or rounded. Placed at the end of the stalk with the long axis of the cell transverse to the long axis of the stalk. Stalks secreted by the cells are slender and twisted. Branch dichotomously or in the form of umbels. Stalks more or less dumb-bell or bisquit-shaped in cross section. Composed of ferric hydroxide, completely dissolving in weak acids. Two polar flagella are present when the cells are motile. Gram-negative. Multiplication by fission of the cells, the daughter cells remaining at first at the end of the stalk; later they may be liberated as swarm cells. Grow only in iron-bearing waters. Do not store manganese compounds. From both fresh and salt water. When the first species was discovered the twisted stalks were thought to be a chain of diatoms.

The type species is Gallionella ferruginea Ehrenberg.

I. Stalks branched.
 * A. Stalks dichotomously branched.
 * 1. Stalks slender, spirally twisted,
 * a. Cells small, stalks very slender.