244 



ORDER I. PSEUDOMONADALES 



26. Vibrio percolans Mudd and Warren, 

 1923. (Jour. Bact., 8, 1923, 447.) 



per'co.lans. L. v. percolo to filter through; 

 L. part. adj. percolans filtering through. 



Curved rods, 0.3 to 0.4 by 1.5 to 1.8 mi- 

 crons, occurring singly or in short chains. 

 Pleomorphic. Actively motile by means of 

 1 to 3 polar flagella. Gram-negative. 



Gelatin stab: No liquefaction. 



Agar colonies: Circular, slightly convex, 

 amorphous, entire. 



Agar slant: Bluish white, glistening 

 streak. 



Broth: Turbid. Pellicle, sediment. 



Litmus milk: Unchanged. 



Potato: White, slimy streak. 



Coagulated blood serum not liquefied. 



Indole not produced. 



No action on carbohydrates. 



Starch not hydrolyzed. 



Nitrites not produced from nitrates. 



Passes through bacterial filters (Berkefeld 

 V candles). 



Aerobic, facultative. 



Optimum temperature, 30° C. 



Non-pathogenic. 



Relationships to other species: Except 

 for polar flagellation, this species has char- 

 acters much like those of Alcaligenes faecalis 

 Castellani and Chalmers. The two species 

 are frequently confused. For example Leh- 

 mann and Neumann renamed Alcaligenes 

 faecalis as Vibrio alcaligenes in their Bakt. 

 Diag., 7 Aufl., 2, 1927, 548, in the mistaken 

 idea that the former organism is polar flagel- 

 late. Leifson and Hugh (personal com- 

 munication, 1954), who recognize the spe- 

 cies Vibrio alcaligenes, report that Vibrio 

 alcaligenes produces nitrites from nitrates 

 and that it does not hydrolyze urea (with 

 possible rare exceptions). They report also 

 that Vibrio alcaligenes occurs more fre- 

 quently in the intestine than does Alca- 

 ligenes faecalis Petruschky. 



Source: Isolated from a hay infusion. 



Habitat: Water. 



27. Vibrio adaptatiis ZoBell and Up- 



ham, 1944. (Bull. Scripps Inst, of Ocean- 

 ography, Univ. Calif., 6, 1944, 258.) 



a.dap.ta'tus. L. part. adj. adaptatus fitted, 

 adapted. 



Curved rods, 0.4 to 0.5 by 1.6 to 2.3 mi- 



crons, only slightly curved, occurring singly 

 and sometimes in pairs. Motile by means 

 of a single, polar flagellum. Gram-negative. 



Note: All differential media except the 

 fresh-water broth, litmus milk and potato 

 were prepared with sea water. 



Gelatin colonies: Pin-point, yellow. 



Gelatin stab: No liquefaction. Yellow, 

 filiform growth along stab. 



Agar colonies: Punctiform, yellow, 

 opaque, pulvinate, smooth. 



Agar slant: Luxuriant, filiform, shiny 

 growth with waxy yellow pigment. 



Sea-water broth: Moderate turbidity; 

 thick, yellow pellicle; slight, flocculent 

 sediment. 



Fresh-water broth: Moderate growth. 



Litmus milk: No visible change. 



Potato : No visible growth. 



Indole not produced. 



Hydrogen sulfide not produced. 



Glucose, sucrose, maltose, lactose, xylose, 

 glycerol, mannitol and salicin not fer- 

 mented. 



Starch not hydrolyzed. 



Non-lipolytic. 



Nitrites not produced from nitrates. 



Ammonia produced from peptone but 

 not from urea. 



Casein not digested. 



Aerobic, facultative (poor anaerobic 

 growth) . 



Optimum temperature, between 20° and 

 25° C. 



Source: Isolated from sea water and from 

 marine sediments. 



Habitat: Common; probably widely dis- 

 tributed. 



28. Vibrio piscium David, 1927. (Cent, 

 f. Bakt., I Abt., Orig., 102, 1927, 46.) 



pis'ci.um. L. noun piscis a fish; L. gen.pl. 

 piscium of fishes. 



Curved rods 0.3 to 0.5 by 2.0 microns. 

 Motile by means of a single, polar flagellum. 

 Gram-negative. 



Gelatin colonies: Circular, granular, 

 opaque. 



Gelatin stab: Napiform liquefaction. 



Agar colonies: Yellowish, circular, 

 smooth, entire, iridescent. 



Agar slant: Light yellow, transparent 

 streak. 



