FAMILY IV. PSEUDOMONADACEAE 



209 



salt): Filiform, slightly raised, smooth, 

 glistening, butyrous, bright red (Lochhead, 

 loc. cit). 



Broth (5 to 35 per cent salt) : No growth. 

 Good growth when grown according to di- 

 rections of Katznelson and Lochhead {op. 

 cit., 1952,97). 



Codfish broth (25 per cent salt): Turbid, 

 dense, pink sediment; imperfect, pink pel- 

 licle. 



Potato immersed in brine: No growth. 



Indole not produced. 



Hj'drogen sulfide is produced. 



No indication of action on carbohydrates. 



Starch not hydrolyzed. 



Cannot utilize inorganic nitrogen as a sole 

 source of nitrogen. Tests (Warburg respir- 

 ometer) show active oxidation of amino 

 acids (such as serine, glutamic acid and as- 

 partic acid); also active oxidation of glj'c- 

 erol. 



Nitrites not produced from nitrates 

 (Lochhead, op. cit., 1934, 275). 



Aerobic. 



Optimum temperature, 37° C. Grows at 

 22° C. 



Optimum salinity, 28 to 32 per cent (Loch- 

 head, loc. cit.). When the salt concentration 

 is reduced to 8 per cent, cells are ruptured. 



Distinctive characters: See Halobacterium 

 cutirubrum. 



Source: Isolated from cured codfish 

 (Harrison and Kennedy, op. cit., 1922, 121) 

 and salted fish (Browne, Absts. Bact., 6, 

 1922, 25, and Proc. Soc. Exp. Biol, and Med., 

 19, 1922, 321) ; also from salted hides (Loch- 

 head, op. cit., 1934, 275). 



Habitat: Produces a reddening of salted 

 fish and hides where untreated solar salt is 

 used. Abundant in tidal pools along shores 

 of tropical seas. Reddens the water in the 

 pools where solar salt is produced as soon as 

 the brine is concentrated to 18 per cent salt. 

 Common on untreated solar salt. 



2. Halobacterium cutirubrum (Loch- 

 head, 1934) Elazari-Volcani, 1940. {Serratia 

 cutirubra Lochhead, Can. Jour. Research, 

 10, 1934, 275; Flavobacterium {Halobacterium) 

 cutirubrum Elazari-Volcani, Studies on the 

 Microflora of the Dead Sea. Thesis, Hebrew 

 Univ., Jerusalem, 1940, 59.) 



cu.ti.ru'brum. L. nonn cutis the skin; L. 

 adj . ruber red; M.L. adj . cutirubrus skin-red. 



Occurs as spheres and rods. The spheres 

 are 1.0 to 2.0 microns in diameter, and the 

 rods measure 0.7 to 4.0 by 1.5 to 8.0 microns. 

 Age of culture and nature of medium influ- 

 ence the size and shape of cells. Rod forms 

 are motile with a single polar flagellum; 

 coccoid forms are motile when young. Gram- 

 negative. 



No growth on ordinary media. 



Milk agar (20 per cent salt to saturation; 

 optimum 28 to 32 per cent) colonies : 3 to 4 

 mm in diameter, round and slightly convex, 

 pink to dark red (rose dorde, Ridgway 

 chart) . 



Milk agar slants: Growth filiform, slightly 

 spreading, rather flat with smooth, glisten- 

 ing surface and membranous consistency. 

 Proteolytic action. 



Liquid media: No or slight growth. Good 

 growth when grown according to directions 

 of Katznelson and Lochhead (Jour. Bact., 

 64, 1952, 97). 



Gelatin (salt): Pronounced liquefaction. 



Indole not produced (Lochhead, op cit., 

 1934, 275) ; faint positive (Gibbons, Jour. 

 Biol. Board Canada, 3, 1936, 75). 



Hydrogen sulfide is produced. 



Tests (Warburg respirometer) show slow 

 oxidation of amino acids (such as serine, 

 glutamic acid and aspartic acid) ; also slow 

 oxidation of glycerol. 



Nitrites not produced from nitrates. 



Diastatic action negative. 



No carbohydrate fermentation. 



Aerobic. 



Optimum temperature, 37°C. 



Salt tolerance: Halophilic, obligate. No 

 rupturing of cells occurs when the salt con- 

 centration is reduced to 8 per cent; rup- 

 turing occurs when the salt concentration is 

 4 per cent. 



Distinctive characters: Resembles Halo- 

 bacterium salinarium. Differs from it in mor- 

 phology and cultural characters, particu- 

 larly as regards color and consistency. More 

 actively proteolytic. Slower oxidative ac- 

 tion on amino acids and glycerol. Ruptur- 

 ing of cells does not occur as rapidly when 

 the salt concentration is reduced. 



