jerinck, Arch, neerl. d. Sci. exact, et natur., £3, 1889, 401; Photobacter phosphoreum Beijerinck, Folia Microbiologica, Delft, 4, 1916, 15; Ford, Textb. of Bact., 1927, 615.) phos.pho're.um. Gr. v. phosphor eo to bring light; M.L. adj. phosphoreus light- bearing. Description taken from Fischer (op. cit., 1888, 107) and Beijerinck {op. cit., 1889, 401). Coccobacilli, 0.5 to 2.0 microns; oc- casional rods are 0.5 to 1.0 micron. In the presence of glucose, especially glucose and asparagine combined, some of the cells tend to branch and to take the form of bac- teroids. Frequently occur as zoogloeae. Non-motile (Fischer); some cells show a sluggish motility (Beijerinck); (Johnson, personal communication, 1953, stated that even electron micrographs failed to reveal flagella) ; actively motile on suitable media (Kluyver, personal communication, June, 1953) ; Leifson (personal communication, July, 1953) reports that an occasional cell of culture L342 from Delft shows mono- trichous flagellation. Stain lightly with aniline dyes. Gram-negative (Manual, 3rd ed., 1930, 178). Gelatin: No liquefaction. Agar slant: Grayish white layer (Manual, loc. cit.). Broth: Slightly turbid with thin pellicle (Manual, loc. cit.). Potato: Ordinary acid potato, no growth; neutralized with sodium phosphate, thin brownish growth (Chester, Ann. Rept. Del. Col. Agr. Exp. Sta., 9, 1897, 124). Proteolytic enzymes not secreted. Glucose, fructose, maltose and galactose are anaerobically fermented with the pro- duction of gas. This is a butanediol fermen- tation that produces H2 and CO2 (Kluyver, personal communication, 1953). Aerobic, facultatively anaerobic. Minimum temperature, between 5° and 10° C. Quality of luminescence: Bluish green. Salt tolerance: To assure phosphorescence and good growth, the osmotic tension of inorganic salt solutions used for cultivation should be equivalent to that produced in a 3 per cent sodium chloride solution. Distinctive characters: Coccoid bacteria which do not liquefy gelatin and which produce acid and gas from glucose but not from lactose. In the presence of glucose, especially when combined with asparagine, the cells swell up greatly and lose their luminescent property. Luminescence on organic matter occurs only when there is a sufficient proportion of inorganic salt. Comments: Several publications which antedate that of Fischer (op. cit., 1888, 107) allude to the fact that the binomial Bac- terium phosphorescens might have been effectively published earlier than 1888. One reference (Anonymous, Nature, 35, 1886- 1887, 377) cites Hermes, the Director of the Berlin Aquarium, as having published an article in which he describes and names as Bacteriian phosphorescens a luminescent organism obtained from a specimen of cod (Gadus callarias) at the Berlin Aquarium; this was the same organism which Fischer secured from the Berlin Aquarium and which he named Bacterium phosphorescens. A second reference (Ludwig, Cent. f. Bakt., 2, 1887, 404) states that Hermes demon- strated before the Berlin Society the phos- phorescent bacterium from the Berlin Aquarium under the name Bacterium phos- phorescens. Other references (Anonymous, Gesell. deutsch. Naturforsch. u. Aerzte, Tageblatt, 60, 1887, 77 and 254) showed that Hermes used this organism several times for demonstration purposes in the Aquarium and before the Society. As Hermes' publication has not been found, and as the binomial Bacterium phosphorescens is not effectively published in anj- of the three references given directly above, Fischer is credited here as the author of this binomial. Considerable confusion exists in the literature concerning this species, most of which can be elucidated by the following: (1) Fischer (Ztschr. f. Hyg., 2, 1887, 54-92) described an organism, isolated from sea water from the West Indies, which he named Bacillus phosphorescens; (2) a second species of phosphorescent bacteria, obtained from the Berlin Aquarium, was described, but not named, by Fischer in a supplement to the work cited above (ibid., 92-95); Leh- mann (Cent. f. Bakt., 5, 1889, 785) also described an organism obtained from the
