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 adaptatus 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.
