FAMILY IV. PSBUDOMONADACEAE 



211 



cent proteose peptoue + 2 per cent KNO3) : 

 Circular, smooth, entire, raised to convex, 

 butyrous, glistening, opaque with a slightly 

 transparent margin which is less colored, 

 orange-brown, orange-red or orange-yellow. 



Agar slant (24 per cent salt + 1 per cent 

 peptone + 2 per cent KNO3): Growth 

 moderate, filiform, raised to convex, glisten- 

 ing, smooth, butyrous, opaque, orange-red. 



Broth (24 per cent salt + 1 per cent pep- 

 tone) : Turbid; orange-red pellicle; slightly 

 viscous sediment. 



Asparagine broth (24 per cent salt + 1 

 per cent asparagine): Turbid. 



Indole not produced. 



Acid from glucose, fructose, mannose and 

 glycerol ; slight acid from xylose and salicin 

 (tests made in 24 per cent salt + 1 per cent 

 peptone + 1 per cent carbohydrate during 

 3 weeks). 



Starch not hj-drolyzed. 



Nitrites rapidly produced from nitrates; 

 gas is produced (tests made in 24 per cent 

 salt + 1 per cent peptone + 2 per cent 

 KNO3). 



Aerobic. 



Optimum temperature, 30° C. 



Salt tolerance: Halophilic, obligate; 

 grows in 18 per cent to saturated salt solu- 

 tions; slight growth in 15 per cent salt. 



Distinctive character: The pigment pro- 

 duces a blue color with concentrated sul- 

 furic acid, thus suggesting a carotenoid; it 

 is very soluble in pyridine, less soluble in 

 methanol, ethanol and chloroform, slightly 

 soluble in acetone, very slightly so in ben- 

 zol and insoluble in xylene and petroleum 

 ether. 



Source: Isolated from Dead Sea water. 



Habitat: Salt lakes. 



5. Halobacteriuin trapanicum (Petter, 

 1931) Elazari-Volcani, 1940. (Bacterium 

 trapanicum Petter, Proc. Kon. Acad. v. 

 Wetensch. Amsterdam, S4, 1931, 1417; also 

 see Petter, Over roode en andere bacterien 

 van gezouten visch. Thesis, Utrecht, 1932; 

 Flavohacterium (Halobacterium) trapanicum 

 Elazari-Volcani, Studies on the Microflora 

 of the Dead Sea. Thesis, Hebrew Univ., 

 Jerusalem, 1940, V and 59.) 



tra.pa'ni.cum. M.L. adj. trapanicus per- 

 taining to "Trapani" salt. 



Rods, 0.6 by 1.5 to 3.5 microns. The length 

 and shape of the cells may vary greatly with 

 the medium: in Dead Sea water + 1 per cent 

 proteose peptone, the cells occur singly and 

 are 0.45 to 0.55 by 1.5 to 4.8 microns with 

 occasional rods measuring 8.0 to 16.0 mi- 

 crons in length; in 24 per cent salt + 1 per 

 cent peptone, the short rods predominate; 

 in 24 per cent salt + 1 per cent peptone + 2 

 per cent KNO3 agar, the cells are ovoid, 

 measuring 1.0 to 1.5 microns in diameter. 

 Non-motile. Gram-negative. 



Gelatin stab (18 per cent salt -f 1 per 

 cent peptone -1- 30 per cent gelatin) : Surface 

 growth. No liquefaction (2 months). 



Agar colonies (24 per cent salt + 1 per 

 cent proteose peptone + 2 per cent KNO3) : 

 Small (1 to 2 mm in diameter), circular, 

 smooth, entire, convex, glistening, trans- 

 parent, light orange or slightly colorless. 



Agar slant (24 per cent salt -f 1 per cent 

 peptone + 2 per cent KNO3): Growth 

 moderate, filiform, raised, glistening, 

 smooth, opaque or slightly transparent, 

 light orange. 



Broth (Dead Sea water -f 1 per cent pep- 

 tone) : Orange-rose pellicle; turbid; orange 

 sediment. In 24 per cent salt + 1 per cent 

 peptone: orange -rose ring; turbid; orange 

 sediment. 



Asparagine broth (24 per cent salt + 1 

 per cent asparagine) : Moderately turbid. 



Indole not produced. 



No acid from arabinose, xylose, glucose, 

 fructose, galactose, mannose, lactose, su- 

 crose, maltose, raffinose, inulin, dextrin, 

 glycerol, mannitol or salicin (tests made in 

 24 per cent salt + 1 per cent peptone + 1 

 per cent carbohydrate during 3 weeks). 



Starch not hydrolyzed. 



Nitrites rapidly produced from nitrates; 

 gas is produced (tests made in 24 per cent 

 salt + 1 per cent peptone + 2 per cent 

 KNO3). 



Catalase-positive. 



Aerobic. 



Optimum temperature, between 30° and 

 37° C. 



Salt tolerance: Halophilic, obligate; 

 grows in 18 per cent to saturated salt solu- 

 tions ; slight growth in 15 per cent salt. 



Distinctive character: The pigment pro- 



