Mar. 24, 1919 Ammonification of Manure in Soil 335 



BACTERIUM TERMO 



The name "Bacterium termo (Miiller) Ehrb." was given by Ehrenberg 

 to what he considered the Monas termo of O. F. Miiller {34). The 

 same name was used by various writers during the next three or four 

 decades to designate almost any motile rod found abundantly in decaying 

 organic matter. Finally Cohn {4, p. 196) described B. termo as a green 

 fluorescent organism obtained from decomposing seeds by making a series 

 of transfers into tubes of Cohn's solution.^ By means of this same technic, 

 a culture has been obtained agreeing fairly well with Cohn's organism, a 

 vigorous denitrifier,^ dififering from all other fluorescent pseudomonads 

 investigated here. Smith (47, p. 170), however, used this technic and 

 obtained a green fluorescent organism differing distinctly (in failure to 

 liquefy gelatin and in having but one instead of two flagella) from the 

 one found in this laboratory. It seems doubtful, therefore, whether 

 Cohn's organism actually represents one or several species; and as there 

 is some question as to whether he was justified in his Emendation of the 

 species, the name is not used in the present bulletin. 



Van Iterson (2j) described a nonliquefying, fluorescent denitrifier (B. 

 denitrofluorescens) which may perhaps be the same as Smith's "S. termo," 

 or closely related to it. Other fluorescent, denitrifying bacteria have 

 been described by Severin {45, 46) and by Jensen {24). It is evident, 

 therefore, that in the group of fluorescent pseudomonads there are certain 

 denitrifiers, one or more of which are especially adapted to growth in 

 Cohn's solution. Severin and Jensen used the designation "Bacillus 

 pyocyaneus" or "Bacterium pyocyaneum" for their fluorescent denitri- 

 fiers, so it is necessary to review the literature relating to the pyocyaneus 

 type of oragnisms. 



PSEUDOMONAS AERUGINOSA 



Pseudomonas aeruginosa (Schroeter) (44, p. 157) Migula {38, p. 884), 

 or Ps. pyocyanea (Gessard, FliiggeY Migula (1900, p. 2g), the blue- 

 pus organism, has long been known, but there has been much confusion 

 as to its name. Many writers have used the specific name "pyocyaneus,'' 

 although others have recognized the priority of aeru^inosus. Bacillus, 

 Bacterium, and Pseudomonas have all three been used as the generic 

 name, according to the generic definitions adopted by different 

 authors. The name "aeruginosa'' seems to be correct.* 



' The formula of this solution is; Distilled water, 1,000 cc; acid potassium phosphate (KHjPOi), s gm.; 

 magnesium sulphate (MgS04), 5 gm.; neutral ammonium tartrate [(NH4)2C4H<06), 10 gm.; potassium 

 chlorid (KCl), 0.5 gm. 



2 The term " denitrification " in this paper is used strictly ro refer to the eliberation of free nitrogen from 

 nitrate, not to the reduction of nitrate to nitrate or ammonia. 



3 Gessard (20) is generally quoted as the author ot the term "pyocyanetis," although he did not employ it 

 in accordance with strict taxonomic usage and apparently referred to an entirely different organism. 

 The first correct use of the name Bacillus pyocyaneus for the true blue-pus organism was by Fliigge 



U6,p.286). 



* The nomenclature of this organism is to be discussed in a paper by R. S. Breed and H. J. Conn, which 

 is now in course of preparation, and will appear shortly in the Journal of Bacteriology. 



