302 



ORDER IV. EUBACTERIALES 



it was one of the commonest species to be 

 found in polluted waters. The description 

 given in the Manual (1st ed., 1923, 135) is 

 taken directly from the Frankland's trans- 

 lation of Eisenberg's original description 

 of this species. As Eisenberg's description 

 makes no mention of certain characteristics, 

 e.g. Gram stain, type of flagellation and 

 action on nitrates, now regarded as very 

 important for the identification of species 

 of this t.ype, Bergey added these characters 

 out of his own studies made on Schuylkill 

 River water; these added characters are 

 indicated above. 



Related species : The Franklands (Micro- 

 organisms in Water. London, 1894, 461) 

 state that the Bacillus liquefaciens of Eisen- 

 berg resembles very closely the Bacillus 

 liquefaciens of Lustig {op. cit., 1890, 99). 

 They then describe the similar organism 

 that they isolated from unfiltered, Thames 

 River water under the name Bacillus li- 

 quidus. This species differs from the Eisen- 

 berg organism in that it produces a thick, 

 flesh-colored, moist expansion on potato. 

 It is also stated to reduce powerfully ni- 

 trates to nitrites. Horrocks (Bact. Exam, 

 of Water. London, 1901, 54) discusses all 

 of these common, gelatin-liquefying bac- 

 teria found in water and adds a description 

 of Bacillus liquefaciens based on his own 

 studies of cultures. Additional characters 

 are given. He states that no gas is produced 

 in a glucose gelatin stab, that milk remains 

 unchanged, that there is a diffuse growth 

 in broth with an abundant deposit of sedi- 

 ment, that nitrates are reduced to nitrites 

 and ammonia, that no indole is produced 

 and that there is no chromogenesis on agar. 

 He adds that it is a short, motile bacillus, 

 often occurring in pairs, that neither forms 

 spores nor grows well at 37° C. His descrip- 

 tion of the chromogenesis produced on po- 

 tato indicates that he regards the B. li- 

 quidus of the Franklands as identical with 

 the B. Uqxiefaciens of Eisenberg. Horrocks 

 describes the growth on potato as variable: 

 sometimes it has a light yellow color, at 

 other times it has a flesh-colored tint chang- 

 ing to reddish brown. 



Because none of the early students of 

 this organism made flagella stains and be- 

 cause one of the most conspicuous of the 



gelatin-liquefying species that would occur 

 on the gelatin plates used so commonly be- 

 fore 1900 in isolating water bacteria is Pseu- 

 domonas fluorescens Migula, it is noteworthy 

 that there is no mention of greenish fluo- 

 rescence in any of the descriptions referred 

 to above. Likewise, the chromogenesis of 

 P. fluorescens on potato is described by 

 earl}' students of this species as an unchar- 

 acteristic brown (Fliigge, Die Mikroorgan- 

 ismen, 2 Aufl., 1886, 289) or as a rather thick, 

 yellowish gray, spreading growth which 

 gradually becomes a light sepia-brown (Mi- 

 gula, Syst. d. Bakt., S, 1900, 886). In search- 

 ing for cultures of a peritrichous, gelatin- 

 liquefying water organism, the organism 

 most likely to be mistaken for it would be a 

 non-fluorescent strain of P. fluorescens. 

 From the fact that several investigators 

 have recently searched for an organism 

 that has the characters of Achromobacter 

 liquefaciens Bergey et al. without finding a 

 peritrichous species that conforms in all 

 respects with the description of Bacillus 

 liquefaciens as given here, it appears that 

 early statements reporting this organism 

 as common in water are based on a failure 

 to distinguish between polar flagellate and 

 peritrichous gelatin-liquefying water or- 

 ganisms. 



Source: Isolated from water. 



Habitat: Found in water. 



2. Achromobacter iophagus (Gray 

 and Thornton, 1928) Bergey et al., 1930. 

 {Bacterium iophagum Gray and Thornton, 

 Cent. f. Bakt., II Abt., 73, 1928, 89; Bergey 

 et al.. Manual, 3rd ed., 1930, 204.) 



i.o'pha.gus. Gr. noun ius poison; Gr. v. 

 phagein to devour; M.L. adj. iophagus poi- 

 son-devouring. 



Rods 0.8 to 1.0 by 1.0 to 5.0 microns. Mo- 

 tile by means of peritrichous flagella. Gram- 

 negative. 



Gelatin colonies: Quicklj^ liquefied. 



Gelatin stab: Liquefaction. 



Agar colonies: Circular or amoeboid, 

 whitish, flat, raised, smooth, translucent, 

 entire. 



Agar slant: Filiform, white to buff, flat, 

 undulate. 



Broth: Turbid. 



Litmus milk: Unchanged. 



