FAMILY VII. MICROCOCCACEAE 



463 



Comment : Also see description of Sarcina 

 littoralis Poulsen. 



Source: Isolated from reddened, salted 

 codfish and herring and from Dead Sea 

 water. 



Habitat: Found in sea-water brine, sea 

 salt and salt lakes; also found to be asso- 

 ciated with a red discoloration of salted fish. 



15. Micrococcus denitrificans Beije- 

 rinck, 1910, emend. Sijderius, 1946. (Beije- 

 rinck, Cent. f. Bakt., II Abt., 25, 1910, 53; 

 also see Elema, De bepaling van de oxydatie 

 reductie potentiaal in bacterien cultures en 

 hare betekenis voor de stofwisseling. Thesis, 

 Delft, 1932; Sijderius, Heterotrophe bac- 

 terien die thiosulfaat oxyderon. Thesis, 

 Amsterdam, 1946.) 



de.ui.tri'fi.cans. L. prep, de away from; 

 L. noun nitrum soda; M.L. noun nitriim 

 nitrate, niter; M.L. v. denitrifico to denitriiy ; 

 M.L. part. adj. denitrificans denitrifying. 



Description prepared by Dr. W. Ver- 

 hoeven, Delft, Holland. 



Non-motile coccus, 1 micron in diameter. 

 Some spindle-shaped, even rod-like forms 

 may be observed in young cultures. In old 

 cultures the typical coccus form is pre- 

 dominant. Sometimes aggregates are ob- 

 served. Gram-negative. 



Grows readilj' on peptone media. Rather 

 salt resistant; develops in media containing 

 no salt to 6 per cent salt. 



Gelatin stab: No liquefaction. 



Agar colonies: Circular, entire, smooth, 

 glistening, white, opaque. 



Broth: Turbid, no pellicle. 



Milk: Unchanged. 



Indole not produced. 



Hydrogen sulfide not produced. 



No acid or gas produced from glucose. 



Nitrates and nitrites are hydrogen ac- 

 ceptors in dissimilation, being reduced to 

 nitrous oxide and nitrogen. Ammonia is not 

 produced. 



Urease activity negative. 



Catalase-positive. 



Aerobic. 



Temperature range, 5° to 37° C. Opti- 

 mum, between 25° and 30° C. 



In denitrification, ethanol, propanol, 

 glycerol, mannitol, glucose, formate, ace- 

 tate, lactate, succinate, fumarate, citrate, 



valerionate or asparagine are suitable hy- 

 drogen donators. 



Grows under autotrophic conditions on 

 thiosulfates as oxidation substrates with 

 the formation of sulfates and sulfuric acid. 

 Sijderius (op. cit., 1946) suggests that 

 Thiobacillus novellvs Starkey is the same 

 as Micrococcus denitrificans Beijerinck. 



Grows readily under autotrophic condi- 

 tions in a hydrogen atmosphere. Also pro- 

 duces good growth on a mineral medium 

 with nitrate in a hydrogen atmosphere, if 

 certain growth factors are added to the 

 medium. 



The relationship of Micrococcus denitrifi- 

 cans to Micrococcus halodenitrificans Robin- 

 son and Gibbons (Can. Jour. Botany, 30, 

 1952, 147) has not been determined. Pre- 

 sumably the latter organism is an obligate, 

 halophilic adaptate of Micrococc^is denitri- 

 ficans (Verhoeven, Koster and van Nievelt, 

 Jour. Microbiol, and Serology, 20, 1954, 

 279). 



Source: Isolated from nitrate media ino- 

 culated with soil. 



Habitat: Presumably widely distributed 

 in soil. 



16. Micrococcus halodenitrificans Rob- 

 inson and Gibbons, 1952. (Robinson and 

 Gibbons, Can. Jour. Botany, SO, 1952, 147; 

 also see Robinson, ibid., 30, 1952, 155, and 

 Robinson, Gibbons and Thatcher, Jour. 

 Bact., 64, 1952, 69.) 



ha.lo.de.ni.tri'fi.cans. Gr. noun hals, 

 halis salt; L. prep de away from; L. noun 

 nitrum soda; M.L. noun nitrum nitrate, 

 niter; M.L. v. denitrifico to denitrify; M.L. 

 part. adj. halodenitrificans salt denitrifying. 



Description prepared by Dr. N. E. Gib- 

 bons, Ottawa, Canada. 



Spherical cells 0.5 micron in diameter. 

 Occur singly or in pairs. Salt concentration 

 has little effect on morphology. Gram-nega- 

 tive. 



Does not grow on media containing less 

 than four per cent salt. Grows readily in 

 peptone media. 



Gelatin stab: Liquefied. 



Agar colonies: Circular, entire, convex, 

 l)utyrous, glistening, opaque, cream- 

 colored. 



Broth: Turbid, no pellicle. 



