266 



ORDER II. CHLAMYDOBACTERIALES 



Growth very abundant, spreading over the 

 entire surface; iridescent. 



Peptone and manganese acetate broth: 

 Abundant growth in the form of loose fiakes. 



Indole not produced. 



Hydrogen sulfide not produced. 



Acetylmethylcarbinol not produced. 



Nitrites produced from nitrates. 



Optimum temperature, 28° C. 



Optimum pH, 8.0. 



Aerobic, but growth favored by the pres- 

 ence of CO2 . 



Habitat: Found in iron-bearing, fresh 

 waters; widely distributed. 



2. Leptothrix thermalis (Molisch, 1925) 

 Dorff, 1934. (Chlamydothrix thermalis Mo- 

 lisch, Sc. Rept. Tohoku Imp. Univ., 4 ser. 

 Biol., Sendae, Japan, 1, 1923, 135 (or pos- 

 sibly 1, 1925, 146); Dorff, Die Eisenorganis- 

 men, Pflanzenforschung, Heft 16, 1934, 38.) 



ther.ma'lis. Gr. noun therme heat; M.L. 

 adj. thermalis pertaining to heat. 



Unbranched trichomes, 0.4 to 0.5 micron 

 thick, united in bundles. Surrounded by a 

 sheath which may store iron and turn 

 brown. 



Source : From warm and hot spring waters 

 in Japan. 



Habitat: Found in warm and hot (37° to 

 74° C.) spring waters. 



3. Leptothrix sideropous (Molisch, 

 1910) Cholodny, 1926. {Chlamydothrix sider- 

 opous Molisch, Die Eisenbakterien, 1910, 

 14; Cholodny, Die Eisenbakterien, Pflanzen- 

 forschung, Heft 4, 1926, 25.) 



si.de'ro.pous. Gr. adj. sideropus or 

 sideropous iron-footed. 



Description taken from Molisch {op. cit. 

 1910, 14) and Cataldi (Estudio Fisiologico 

 y Sistemdtico de Algunas Chlamydobac 

 teriales. Thesis, University of Buenos Aires 

 1939, 62 and 66). 



Cells rod-shaped, 0.5 to 0.8 micron 

 Motile. Trichomes short and unbranched 

 Sheath very thin and colorless, giving an 

 iron reaction only at the base of the tri 

 chome. Attached by a broad holdfast which 

 gives a marked iron reaction. Not acid-fast. 

 Gram-negative. 



Gelatin: No liquefaction. 



Iron citrate and ammonium agar colonies : 

 Very filamentous. Colonies and filaments 

 encompassed by a spattering of rust-colored 

 spots. 



Manganese acetate agar colonies: Large 

 and filamentous, the filaments being 

 strongly colored. 



Iron citrate and ammonium agar slant: 

 Growth in the form of isolated colonies; 

 strongly colored. 



Manganese acetate agar slant: Abundant 

 growth which adheres to the medium except 

 in those places covered with water of con- 

 densation. 



Peptone and manganese acetate broth: 

 Firm pellicle with a metallic sheen. 



Indole not produced. 



Hydrogen sulfide not produced. 



Acetylmethylcarbinol not produced. 



Nitrites produced from nitrates. 



Optimum temperature, between 25° and 

 28° C. 



Optimum pH, 8.0. 



Aerobic; growth not favored by the pres- 

 ence of CO2 . 



Habitat: Found growing on the surfaces 

 of objects submerged in water; widely dis- 

 tributed. 



4. Leptothrix discophora (Schwers, 

 1912) Dorff, 1934. (Megalothrix discophora 

 Schwers, Cent. f. Bakt., II Abt., 33, 1912, 

 273; Leptothrix crassa Cholodny, Cent. f. 

 Bakt., II Abt., 61, 1924, 292; Dorff, Die 

 Eisenorganismen, Pflanzenforschung, Heft 

 16, 1934, 31.) 



dis.co'pho.ra. Gr. noun discus a disc; Gr. 

 adj. phorus bearing; M.L. adj. discophorus 

 disc-bearing. 



Description taken from Schwers (op. cit., 

 1912, 273) and Cataldi (Estudio Fisiologico 

 y Sistemdtico de Algunas Chlamydobac- 

 teriales. Thesis, University of Buenos 

 Aires, 1939, 60 and 66). 



Cells 0.5 by 0.8 micron. Motile. Tri- 

 chomes long, slender, articulated, composed 

 of elements of varjdng length showing 

 false branching (Cholodny, Cent. f. Bakt., 

 II Abt., 61, 1924, 297). Usually attached to 

 a submerged substrate, but may be free- 

 floating. A sheath, thick (10 to 15 microns) 

 at the base, tapering toward the free tip 



