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 Nauinann, 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. hactrum 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 hrevis. 

 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. 



