BACILLI 453 



BACILLUS AEGENTEO-PHOSPHOEESCENS 

 LIQUEFACIENS 



LIQUEFIES GELATINE 



Authority.— Katz, ' Zui Kenntniss cler Leuchtbakterien,' Centralblatt f. 

 Bakteriologie, vol. is., 1891, p. 158. 



"Where Found. — In sea-water, a short distance from Sydney. Probably 

 identical with the Photobacterium limiinosmn of Beyerinck (No. 1, a. Arch. 

 Neerland., vol. xxiii., 1889, p. 403). See also a careful study of phosphorescent 

 bacteria in general, communicated by Beyerinck to the Dutch Academy of 

 Sciences, Transactions, Amsterdam, 1890. 



Microscopic Appearance.— Straight or slightly bent bacilli, with rounded 

 ends, about 2-5 fi long, and about one third as wide. Stains well with Loeffler's 

 methylene blue. Very motile in drop cultures, where it forms masses of longer 

 and shorter threads, bent and interwoven. No spore formation observed. 



Cultures. — 



Gelatine Plates.— At from 17° to 20° C. small hyaline coloured discs appear 

 in twenty-four hours on the surface, which under a low power are very finely 

 granular and light brown in colour, with irregular and lobular periphery. The 

 depth colonies are, under a low power, straw-yellow in colour, and their surface 

 pitted, resembling a mulberry in appearance, the contour being wavy. In two 

 days hollow liquid depressions enclose each colony, which sinks to the bottom. 

 Later on a yellowish white mass, surrounded by a grey turbid band, is the 

 appearance of the liquid colonies, whilst under a low power a zone extends from 

 this band, and numerous minute radial hair-like threads ramify into the still 

 solid gelatine. After being cultivated through forty-one generations the lique- 

 faction was much retarded, the liquid depressions not appearing until about the 

 eighth day, the colonies meanwhile forming considerably large circular and 

 thin expansions. 



Gelatine Tubes. — On surface growth resembles the appearance of typical 

 plate -cultures of the bacillus. The liquefaction proceeds rapidly, and a yellowish 

 stringy deposit forms at the bottom of the tube. A pellicle forms on the surface, 

 and the liquid, although at first turbid, becomes clear. No thread-like exten- 

 sions are visible at the edge of the liquid depression or in the needle's path in 

 the depth. 



Agar-agae. — Forms a whitish grey viscid expansion, which, beyond its 

 phosphorescent properties, is not characteristic. 



Bkoth,— -Benders the liquid turbid, and produces a deposit and a pellicle on 

 the surface. Later the liquid becomes clear. 



Remarks. — It is facultatively anaerobic. Grows best at 25° C; an exposure to 

 32° to 34° C. for two and a half days destroys it, whilst at 13° to 15° C. its development 

 18 retarded. Sterilised distilled water kills the bacilli in a short time (fourteen hours 

 at 17° to 20° C). Its phosphorescence is easily lost in cultures, but may be restored 

 by being cultivated on cooked ' garfish.' 



