FAMILY BEGGIATOACEAE 



995 



Beggiaioaceae have been described under 

 various names as follows : 



Conidiothrix sidphtirea Petersen. 

 (Dansk Botan. Arkiv., 1, 1921, 1.) 



Filamentous, nonmotile organisms, of 

 uniform width, bet^^een 0.5 and 1 mi- 

 cron in diameter, covered on the outside 

 with sulfur. Segmentation not re- 

 ported. The outstanding characteristic 

 of the genus Conidiothrix is the supposed 

 multiplication of the filaments by means 

 of conidia which arise bj^ budding on the 

 filament. Apart from this reported oc- 

 currence of a budding process, the de- 

 scription is similar to that of Lcploihrix 

 sulphnrea and of Thiolhrix tenuis and 

 Thiothrix tenuissima. Since consecu- 

 tive observations on growing organisms 

 are lacking, it seems advisable to con- 

 sider Conidiothrix sulphnrea as probably 

 identical with Thiothrix tennis or Thio- 

 thrix tenuissima. 



Leptothrix sulphnrea IMiyoshi. (Jour. 

 Coll. Sci., Imp. Univ. Tokj'o, Japan, 10, 

 1897, 154.) 



Filamentous, non-motile organisms, 

 of uniform width, not exceeding 0.7 mi- 

 cron in diameter. The filaments are 

 covered on the outside with a powdery 

 deposit of elementary sulfur. Seg- 

 mentation observable only after special 

 staining; length of segments not pub- 

 lished. 



Found by Miyoshi in sulfur springs in 

 Japan. Although not reported as con- 

 taining sulfur globules inside the fila- 

 ments, the description would closely fit 

 Thiothrix tenuis or Thiothrix tenuissima 

 Winogradsk}'. The latter have been ob- 

 served in masses covered on the outside 

 with elementary sulfur. Therefore, it 

 seems likely that Leptothrix sulphnrea 

 is a synonym for Thiothrix tenuis or 

 Thiothrix tenuissima. 



Thionema vaginatvm Kolkwitz. (Bcr. 

 d. deut. bot. Ges., 56, 1938, 11.) 



The type species of the genus 

 Thionema. 



Described as a filamentous, colorless 

 sulfur bacterium, non-motile, attached 

 in the manner of Thiothrix. Filaments 

 1.5 to 2 microns in diameter, segmented. 

 Segments 2 to 5 microns long. Repro- 

 duction, as in the case of Thiothrix, by 

 means of detached segments. 



While this part of the description fits 

 that of Thiothrix nivea, the new generic 

 name was proposed on the basis of the 

 occurrence of a distinct sheath, fre- 

 quently impregnated with iron com- 

 pounds. Since Winogradsky mentions 

 the occurrence of a sheath also in Thio- 

 thrix nivea, it seems desirable to consider 

 Thionema vaginatum, at least for the 

 time being, as a probable sj^nonym of 

 Thiothrix nivea. 



Source : Found on waterplants in the 

 Teltow-Canal near Berlin, the water 

 containing hydrogen sulfide and iron 

 salts. 



Thiosiphon adriaticum Ivlos. (Sitz- 

 ungsber. Akad. d. Wissensch. Wien, 

 Mathem.-naturw. KL, I, U5, 1936, 209.) 



Described as a filamentous sulfur bac- 

 terium, non-motile, but without seg- 

 mentation, hence tubular and unicellu- 

 lar. Multiplication bj^ means of conidia 

 arising from restriction of the apical part 

 of the cell. Length of filament about 1 

 to 1.5 mm, width 17 to 53 microns, usually 

 tapering towards ape.x. Conidia 13 to 

 30 microns by 30 to 50 microns. 



The description is at variance with the 

 appearance of the organism in the pub- 

 lished photomicrograph in so far as the 

 size of the conidia is concerned. From 

 the photomicrograph this appears to be 

 about 30 b}' 200 microns. The entire 

 appearance is strongly reminiscent of 

 that of Beggialoa mirabilis (Beggiatoa 

 gigantca) in certain cultures. The short 

 conidia, described in the text, strikingly 

 resemble species of Achromatium. Con- 

 secutive observations on growing cul- 

 tures of Thiosiphon do not appear to 



