ORDER I. PSEUDOMONADALES 



Short rods, 0.5 by 1.0 to 2.0 microns. Mo- 

 tile by means of six to eight long flagella. 

 Gram-negative. 



Gelatin stab: Slow liquefaction. No 

 chromogenesis. 



Thiosulfate agar: Colonies small, white, 

 1 mm in diameter. 



Thiosulfate liquid medium: Verj' little 

 visible turbiditjs no sulfur precipitated. 

 Produces sulfate and tetrathionate with in- 

 crease in pH. Rate of thiosulfate oxidation 

 increased by presence of organic com- 

 pounds. 



No acid or gas from sugars. 



Nitrites and gas produced from nitrate- 

 peptone broth; no ammonia produced. May 

 live anaerobically in the presence of ni- 

 trates. 



Indole not produced. 



Hydrogen sulfide not produced. 



Starch is hydrolyzed. 



Lipolytic. 



Catalase-positive. 



Non-hemolytic. 



Temperature relations: Optimum, 27° C. 

 Minimum, 6.9° C. Maximum, l^etween 36.5° 

 and 40° C. Death occurs in 2 to 5 minutes at 

 55° C. 



Optimum pH, between 7.9 and 8.5. pH 

 limits, 6.0 and 10.0. 



Comments: Trautwein (Cent. f. Bakt., II 

 Abt., 61, 1924, 5) regards his bacterium as 

 being closely related to the fluorescent 

 group and to the denitrifying bacteria of 

 Burri and Stutzer. Starkey (Jour. Gen. 

 Physiol., 18, 1935, 346) reports this species 

 to be heterotrophic. However, Lehmann (in 

 Lehmann and Neumann, Bakt. Diag., 7 

 Aufl., ^, 1927, 516), under whom Trautwein 

 did his work, reports that this species is a 

 facultative autotroph as does Parker also 

 (Jour. Gen. Microbiol., 3, 1953, 344). As 

 facultatively autotrophic species are in- 

 cluded in Thiobacillus as defined, this 

 species has again been included in Thio- 

 bacillus (see Manual, 2nd ed., 1925, 39). 

 Starkey 's culture B and Parker's M cul- 

 ures appear to be identical with Thioba- 

 cillus trautweinii. 



Source: Isolated from soil and water 

 (Trautwein) and from purified sewage from 

 Wiirzburg (Lehmann). 



Habitat: Widely distributed in polluted 

 waters and soil. 



FAMILY IV. PSEUDOMONADACEAE WINSLOW ET AL., 1917. 



(Winslow, Broadhurst, Buchanan, Krumwiede, Rogers and Smith, Jour. Bact., 2, 1917, 555.) 

 Pseu.do.mo.na.da'ce.ae. M.L. fem.n. Pseudomonas tj'pe genus of the family; -aceae 

 ending to denote a family; M.L. fern. pi. n. Pseudomonadaceae the Pseudomonas family. 



Cells elongate, straight rods, occasionally coccoid. Motile by means of polar flagella 

 which are either single or in small or large tufts. A few species are non-motile. Gram-nega- 

 tive. May possess either water-soluble pigments that diffuse through the medium or non- 

 water-soluble pigments. Usually grow well and fairly rapidly on the surface of culture 

 media. Aerobic. Frequently oxidative in their physiology but may be fermentative. Usually 

 found in soil or water, including sea water or even heavy brines. Many plant and a few 

 animal pathogens. 



Key to the genera of family Pseudomonadaceae. 



I. Attack glucose and other sugars either oxidatively or fermentatively. 



A. Genera in which the species are either known or are thought to attack glucose oxi- 

 datively. 



1. Bacteria which do not produce readily detectable acetic acid though they may 

 oxidize ethanol. May produce a water-soluble pigment which diffuses through 

 the medium, 

 a. Cultures may or maj' not produce a water-soluble pigment which is bluish, 

 greenish or brownish in color. Rose, lilac- and yellow-colored, diffusible pig- 

 ments occasionally occur. 



