Page:Bergey's manual of determinative bacteriology.djvu/219

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FAMILY IV. PSEUDOMONADACEAE
197

4. Photobacterium harveyi (Johnson and Shunk, 1936) Breed and Lessel, 1954 (Achromobacter harveyi Johnson and Shunk, Jour. Bact., 31, 1936, 587; Breed and Lessel, Antonie van Leeuwenhoek, 20, 1954, 61.)

har'vey.i. M.L. gen. noun harveyi of Harvey; named for E. N. Harvey.

Description taken from Johnson and Shunk (op. cif., 1936, 587).

Rods, .0.5 to 1.0 by 1.2 to 2.5 microns, occurring singly or in pairs, with rounded ends. Occasionally slightly curved; ends occasionally slightly pointed. Non-spore-forming. Not encapsulated. Motile by means of a single, polar flagellum 2 to 3 times the length of the cell. Gram-negative.

Sea-water gelatin colonies: After 24 hours at 20° C, circular, about 1.5 mm in diameter or larger, margin slightly undulate, sunken due to the beginning of liquefaction, interior somewhat zonate; colonies surrounded by a halo of numerous small secondary colonies, circular and finely granular. In crowded plates a large number of gas bubbles are formed. Luminescent.

Sea-water gelatin stab: Rapid saccate liquefaction complete in 5 days at 22° C. Abundant flocculent sediment.

Sea-water agar colonies: Mostly very large, 6 to 8 cm in diameter in 24 hours, flat, highly iridescent, circular with undulate margin, or composed of narrow and close or wide filamentous growth. Occasionally small colonies appear that are circular, with entire or slightly undulate margin, often producing irregular secondary growth, surface always smooth. Luminescent.

Sea-water agar slant: Growth abundant, spreading, grayishly viscous, homogeneous, iridescent, the medium becoming rapidly alkaline whhen inoculated at an initial pH of 7.0. With fish decoctions added to the medium, luminescence is much brighter and growth becomes brownish after several days.

Growth on autoclaved fish: Abundant, smooth, glistening, yellowish, becoming dirty brown after several days. Mild putrefactive odor. Luminescence very brilliant.

Sea water containing 0.2 per cent peptone : Abundant uniform turbidity, thin pellicle, sediment accumulating over a period of several days. Luminescence at surface only unless the tube is shaken.

Milk, with or without the addition of 2.8 per cent salt: No growth.

Potato plugs resting on cotton saturated with sea water: Growth slight, somewhat spreading, slightly brownish. Luminous.

Indole produced (Gore's method).

Hydrogen sulfide is produced (ZoBell and Fantham method).

Fixed acid from glucose, fructose, mannose, galactose, sucrose, maltose, mannitol, dextrin, glycogen, trehalose, cellobiose; slowly from salicin. Non-fixed acid from melezitose; slight acid from sorbitol, disappearing in 24 hours. No acid from glycerol, xylose, arabinose, dulcitol, inositol, adonitol, erythritol, arabitol, lactose, raffinose, rhamnose, fucose or alpha methyl glucoside.

Starch agar: Wide zone of hydrolysis.

Nitrites produced from nitrates.

Ammonia produced in peptone media (Hansen method).

Aerobic, facultatively anaerobic.

Temperature relations: Optimum, between 35° and 39° C. Abundant growth between 22° and 25° C. Optimum temperature for luminescence, between 20° and 40° C.

Optimum pH forluminescence, between pH 7.4 and 7.8.

Quality of luminescence (to completely dark-adapted eyes) : Yellowish green to green on fish and typically green on seawater agar or gelatin.

Not pathogenic for white rats or amphipods.

Distinctive character: Luminescence not favored by the presence of glycerol in the medium.

Source: Isolated from a dead amphipod (Talorchesda sp.) at Woods Hole, Massachusetts.

Habitat: Sea water.

Note: Species incertae sedis. Additional luminescent bacteria which probably belong in this genus have been reported in the literature. However many of the descriptions are not adequate enough to permit the determination of the identity and relationships of these organisms.