FAMILY IX. BREVIBACTERIACEAE 



503 



Short rods which at first hang very closely 

 together usually in pairs, also in fours or 

 longer chains. Later, however, longer chains 

 are regularly formed. The diameter of the 

 cells is about 0.5, the length 1.5 to 2.5, 

 microns, at times as long as 4.5 microns. The 

 rods rotate on their long axis (Lehmann 

 and Neumann state that their culture was 

 non-motile). Gram-positive. 



Gelatin plates: The colonies within the 

 gelatin are small, spherical bodies that are 

 bright yellow in color. The colonies on the 

 surface are highly convex, bright yellow, 

 tin}' drops which lie in a shallow depression. 

 When examined under low magnification, 

 the colonies beneath the surface appear as 

 pale yellowish to brownish, granular, cir- 

 cular, sharply contoured discs. The colonies 

 on the surface also show a sharp contour for 

 some time; however, they later become 

 somewhat irregular in contour and appear 

 much darker brown by transmitted light. 



Gelatin stab : An elevated growth is formed 

 at first on the surface. This is a definite 

 Naples-yellow in color. This growth gradu- 

 ally spreads until it almost reaches the glass 

 wall of the test tube. By this time the gela- 

 tin is liquefied in a shallow layer. There is 

 little development along the stab. The lique- 

 faction proceeds slowly. 



Agar slant: There is an abundant, rather 

 rapid growth that is of a definite light yellow 

 color as on gelatin. (Lemon-yellow, Leh- 

 mann and Neumann.) 



Bouillon broth: The broth becomes some- 

 what lighter in color with little turbidity at 

 first; then flecks form and settle, appearing 

 as a j'ellowish white sediment. 



Potato: The yellow growth is abundant, 

 becoming thickened and glistening. The 

 color becomes somewhat greenish but not 

 enough to call it sulfur-yellow. 



Indole is not produced (Lehmann and 

 Neumann) . 



Hydrogen sulfide is actively produced 

 (Lehmann and Neumann). 



No gas produced from glucose (Lehmann 

 and Neumann). 



Milk is coagulated (Lehmann and Neu- 

 mann). 



Optimum temperature, about 25° C. 



Aerobic. 



The specific epithet helvolits is suggested 

 because of its pale yellow chromogenesis on 

 agar plates. 



Comments: It will be seen that the de- 

 scription by Zimmermann differs in several 

 important respects from that given in the 

 6th edition of the Manual, 1948, 395; the 

 latter was taken largely from Jensen (Proc. 

 Linn. Soc. New So. Wales, 59, 1934, 37). The 

 morphology of the Zimmermann organism 

 both as described by him and also by Leh- 

 mann and Neumann is that of a simple, 

 unbranching rod. There is no suggestion of 

 a pleomorphic morphology, snapping divi- 

 sion or branching. The description given by 

 Jensen is indicative of a different species, 

 and when Lochhead compared a culture of 

 Jensen's organism with cultures of related 

 organisms, he found it (personal communi- 

 cation, 1954) to be identical with cultures of 

 Bacterium globiforme Conn, the organism 

 selected as the type species of the genus 

 Arthrobacter Conn and Dimmick. Zimmer- 

 mann 's organism clearly was a Brevihac- 

 terium as defined here, not a Corynebacter- 

 ium as defined by Lehmann and Neumann 

 (Bakt. Diag., 1 Aufl., 2, 1896, 380). Brevi- 

 hacterium represents a segregation of species 

 placed by Lehmann and Neumann in Bac- 

 terium. 



Source : Isolated from Chemnitz tap water 

 (Zimmermann) ; also found as a dust con- 

 taminant in Wiirzburg (Lehmann and Neu- 

 mann). 



Habitat: Presumably widely distributed 

 in nature. 



Genus II. Kurthia Trevisan, 1885. 



(Trevisan, Atti della Accad. Fisio- Medico- Statistica in Milano, Ser. 4, S, 1885, 92; 

 Zopfius Wenner and Rettger, Jour. Bact., 4, 1919, 334.) 



Kurth'i.a. M.L. fem.n. Ki<r/Am named for H. Kurth, the German bacteriologist who de- 

 scribed the type species. 

 Long rods with somewhat rounded ends. In liquid media the cells are aligned in evenly 



