FAMILY II. VITREOSCILLACEAE 



849 



1. Bactoscilla flexibilis Pringsheim, 

 1949. (Pringsheim, Bact. Rev., 13, 1949, 72; 

 Bactoscilla tnobilis Pringsheim, Jour. Gen. 

 Microbiol., 5, 1951, 144.) 



flex.i.bil'is. L. adj. flexibilis flexible. 



Short, slender trichomes, about 0.4 to 

 0.5 micron in diameter, composed of a num- 

 ber of slender, rod-shaped cells apparently 

 separated bj^ empty interspaces. The tri- 

 chomes bend slowly and pronouncedly at 

 the joints, the individual cells remaining 

 straight. Motile. Gram-negative. 



Relationship to other species: Structur- 



all}^ comparable to Ldneola articulata which 

 is, however, motile by means of peritri- 

 chous flagella. 



Source: Found in scum composed mainly 

 of Myjophyceac from the outlet of the 'Clay 

 Pond' near the Freshwater Biological Asso- 

 ciation laboratorj^ at Wraj^ Castle, Amble- 

 side, later in the surface film of water over 

 black mud from Flatford Mill Field Centre 

 and a third time in mixed material from a 

 duck pond near Colchester, all in England. 



Habitat: Found in fresh water containing 

 decomposing organic material. 



Genus III. Microscilla Pringsheim, 1951. 



(Microscilla Pringsheim {nonien nudum), Bact. Rev., 13, 1949, 72; Pringsheim, 

 Jour. Gen. Microbiol., 5, 1951, 127 and 140.) 



Micros. cil'la. Gr. adj. micrus small; L. noun osrillum a swing; M.L. fem.n. Microscilla 

 the small oscillator. 



Slender trichomes without perceptible septation. Motile by means of active, gliding move- 

 ments. Gram-negative. Reproduction is by division into relatively long daughter trichomes. 

 Found on fresh-water and marine algae. 



The type species is Microscilla marina Pringsheim. 



Key to the species of genus Microscilla. 



I. From salt water. Sea water or artificial sea water required for growth. 



1. Microscilla marina. 



II. From fresh water. Sea water or artificial sea water not required for growth. 



A. Trichomes possess a free-swinging end. 



2. Microscilla flagellum. 



B. Trichomes do not possess a free-swinging end. 



3. Microscilla ngilis. 



1. Microscilla marina Pringsheim, 1951. 

 (Vitreoscilla marina Pringsheim (nomen 

 nudum), Bact. Rev., 13, 1949, 72; Prings- 

 heim, Jour. Gen. Microbiol., 5, 1951, 140.) 



ma.ri'na. L. adj. marinus pertaining to 

 the sea, marine. 



Slender trichomes, 0.5 to 0.6 by up to 

 100 microns, apparently without septation. 

 The gliding movement, active and quick, 

 particularly in young cultures from liquid 

 media, is not associated with rotation but 

 with much bending and waving. Gram-nega- 

 tive. 



Sea water is required for growth. 



Sea-water agar: Growth barely percepti- 

 ble as a grayish veil. Microscopically the 

 veil is seen to consist of a delicate network 

 of widely separated trichomes forming 

 loops and meshes. 



On a medium composed of sodium acetate 

 (0.1 per cent), Difco yeast-extract (0.1 per 

 cent), Bactotryptone (0.1 per cent), soil 

 extract (5 per cent), artificial sea water 

 (half concentrated) and agar (1 per cent) 

 and neutralized with calcium carbonate, 

 a thick, peach- to orange-colored layer is 

 produced after 4 days; after one week, the 

 rich orange growth disappears due to au- 

 tolysis of the cells; smaller growths keep 

 their filamentous appearance for several 

 weeks. 



Liquid media: Growth occurs in floating 

 bundles of more or less parallel trichomes 

 gliding along one another. 



Source: Isolated from fragments of Schizo- 

 nema (diatoms) filaments from Brighton, 

 Sussex, England. 



Habitat: Found on marine algae. 



