Page:Bergey's manual of determinative bacteriology.djvu/248

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226
ORDER I. PSEUDOMONADALES

2. Siderococcus communis Dorff, 1934. (Die Eisenorganismen, Pflanzenforschung, Jena, Heft 16, 1934, 9.) com.mu'nis. L. adj. communis common. Cocci to short rods, 0.4 to 1.0 micron in diameter, occurring singly or in chains. No capsules observed. Utilize organic iron compounds (ferrous ammonium citrate) and produce precipitates of ferric oxide. Do not grow in water containing inorganic iron compounds such as iron carbonate. Do not grow on glass slides submerged in w^ater containing organic iron compounds but are found in the precipitate that is formed. Source: Found in many European coun- tries and in North America. Habitat: Widely distributed in water containing organic iron compounds.

Genus IX. Siderobacter Naumann, 1922.

(Kungl. Svenska Vetenskapsakad. Handl., 62, No. 4, 1922, 55.)

Si.de.ro.bac'ter. Gr. noun siderus iron; M.L. noun bacter the masculine form of the Gr. neut. n. bactrum a small rod; M.L. mas.n. Siderobacter iron rodlet.

Cells bacilliform with rounded ends; occur singly, in pairs or in short chains or are united to form colonies. Lack a gelatinous capsule. Iron or manganese compounds are deposited on the surfaces or in the membranes of the cells; the deposit may also be entirely outside of the cells. Flagellated cells may occur. Found in neutral or alkaline waters.

The type species is Siderobacter linearis Naumann.

Key to species of genus Siderobacter.

I. Cells less than 1.0 micron in diameter. Found on the surface of zoogloeal masses.

A. Cells less than 0.5 micron in diameter.

1. Siderobacter gracilis.

B. Cells 0.8 micron in diameter.

2. Siderobacter brevis.

II. Cells 1.0 micron or greater than 1.0 micron in diameter.

A. Cells 1.0 micron in diameter.

3. Siderobacter linearis.

B. Cells greater than 1.0 micron in diameter.
1. Cells in pairs and 1.5 microns in diameter.

4. Siderobacter duplex.

2. Cells 2.5 microns in diameter. Participate in the formation of iron and lime concretions of macroscopic size.

5. Siderobacter latus.

1. Siderobacter gracilis Beger, 1949. (Zent. f. Bakt., I Abt., Orig., ISJt, 1949, 65.) gra'ci.lis. L. adj. gracilis slim, slender. Cells 0.4 by 3.0 microns. Encrusted cells are 5.0 to 7.0 microns long. Occur singly. Participate in the formation of deposits of iron compounds. Source: Found on the surface of masses of Zoogloea filipendula. This species formed thick coatings on the walls of two wells supplying rapid sand filters near Berlin, Germany. The filters required frequent washing because the coatings were easily detached. Habitat: Found in the cool waters of deep wells.

2. Siderobacter brevis Beger, 1949. (Zent. f. Bakt., I Abt., Grig., 1S4, 1949, 65.) bre'vis. L. adj. brevis short. Cells, 0.8 to 1.0 by 3.0 to 4.0 microns, usually occurring singly. Participate in the formation of deposits of iron compounds. Source : Found on the surface of masses of Zoogloea filipendula. This species formed thick coatings on the walls of two wells supphdng rapid sand filters near Berlin, Germany. The filters required frequent washing because the coatings were easily detached.

3. Siderobacter linearis Naumann, 1922.