992 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Klas, Arch. f. MikrobioL, 8, 1937, 318.) 

 From Latin mirabilis, wonderful. 



Filaments 15 to 21.5, average 17 mi- 

 crons in diameter. The so-defined spe- 

 cies does not overlap with Beggiatoa 

 gigantea according to Klas (loc. cit.). 

 Segmentation usually observable with- 

 out special treatment; segments 5 to 13, 

 average 8.5 microns long. Terminal 

 cells rounded or tapering, sometimes 

 bent. 



When the filaments are in healthy 

 condition they are of uniform width ; an 

 unfavorable environment induces bulg- 

 ing of the sides. 



Habitat: Apparently restricted to ma- 

 rine environments containing h5^drogen 

 sulfide. Common on decaying marine 

 algae. 



Uphof (Arch. f. Hydrobiol., 18, 1927, 

 83) has created a species, Beggiatoa 

 maxima, which on account of its diam- 

 eter (10 to 20 microns) falls partly within 

 the range of Beggiatoa mirabilis, partly 

 within Beggiatoa, arachnoidea. Since 

 it was found in a fresh water environ- 

 ment, the habitat of Beggiatoa mirabilis 

 may not be restricted to marine media. 



3. Beggiatoa arachnoidea (Agardh) 

 Rabenhorst. {Oscillatoria arachnoidea 

 Agardh, Regensburger Flora, 1827, 634; 

 Rabenhorst, Flora europaea algarum, 

 1865, 94; Beggiatoa pellucida Cohn, Hed- 

 wigia, 4, 1865, 82; ? Oscillatoria beggia- 

 toides Arzichowsky, Bull. Jard. Imp. 

 Bot., St. Petersb.,^, 1902, 38, 47; includes 

 the larger members of Beggiatoa major 

 Winogradsky, Beitr. z. Morph. u. Phy- 

 siol, d. Bact., I, Schwefelbacterien, 1888, 

 25; and the smaller ones of Beggiatoa 

 maxima Uphof, Arch. f. Hydrobiol., 18, 

 1927, 80.) From Greek, resembling a 

 cobweb. 



Filaments 5 to 14 microns in diameter. 

 Segmentation generally observable only 

 after special staining or removal of sulfur 

 globules; segments 5 to 7 microns in 

 length. Terminal cells rounded, often 

 tapering. Filaments of uniform width. 



Habitat : Both fresh water and marine 

 environments containing hydrogen sul- 

 fide. 



4. Beggiatoa alba (Vaucher) Trevisan. 

 {Oscillatoria alba Vaucher, Histoire des 

 Conferves d'eau douce, 1803, 198; Beg-i 

 giatoa punctata Trevisan, Prospetto 

 della Flora Euganea, 1842, 56; Beggiatoa 

 alba var. marina Cohn, Hedwigia, 4, 

 1865, 83; Beggiatoa marina Molisch, 

 Cent. f. Bakt., II Abt., 33, 1912, 58; in 

 part, Beggiatoa major Winogradsky, 

 Beitr. z. Morph. u. Physiol, d. Bact., I, 

 Schwefelbacterien, 1888, 25.) From La- 

 tin albus, white. 



This is the type species of the genus. 



Filaments 2.5 to 5, most commonly 3 

 microns in diameter, of even width. 

 Segmentation difficult to detect in fila- 

 ments containing many sulfur globules; 

 segments 3 to 9 microns long, shortly 

 after division practically scjuare. Ter- 

 minal cells rounded. 



Habitat : Both fresh water and marine 

 environmenls containing hydrogen sul- 

 fide. 



Distribution: Ubiquitous, and prob- 

 ably the most conmion of the fila- 

 mentous sulfur bacteria. 



5. Beggiatoa leptomitiformis (Mene- 

 ghini) Trevisan. {Oscillatoria leptomiti- 

 formis Meneghini, Delle Alghe viventi 

 nelle terme Euganee, 1844, 122; Trevisan, 

 Prospetto della Flora Euganea, 1842, 56; 

 Beggiatoa media Winogradsky, Beitr. z. 

 Morph. u. Physiol, d. Bact., I, Schwefel- 

 bacterien, 1888, 25.) From Greek leptos, 

 small and mitos, thread and Latin 

 forma, shape. 



Filaments 1 to 2.5 microns in diameter, 

 of uniform width. Segmentation only 

 observable after removal of sulfur glob- 

 ules; segments 4 to 8 microns in length. 

 Terminal cells usually rounded. 



Habitat: Fresh water and marine en- 

 vironments containing hydrogen sulfide. 



