FAMILY III. STREPTOMYCETACEAE 



793 



spiral formation; spirals long and open, not 

 compact. 



Gelatin: P^locculent growth. No aerial 

 mycelium. Rapid liquefaction. No pigment 

 production. 



Agar: Brown-colored growth covered with 

 tiny patches of ivorj^-colored aerial mj^ce- 

 lium. 



Synthetic agar: Same as on glucose agar. 



Potato: Abundant brownish growth with 

 white to mouse-gray aerial mycelium. 



Glucose agar: Thin yellowish growth, 

 later turning reddish brown; no soluble pig- 

 ment; light gray to mouse-gray mj'celium 

 with white edge. Tj'pical odor of strepto- 

 myces . 



Strong proteolytic enzymes acting on 

 casein and gelatin. 



Strong diastatic action; no sugar or dex- 

 trin left in 1 per cent starch solution after a 

 few days. 



Limited reduction of nitrate. 



Antagonistic properties: Certain strains 

 produce an antibiotic designated as cacao- 

 mycetin. 



Source: Three strains were isolated from 

 cacao beans in Nigeria. There were slight 

 differences among the three strains; the 

 above description is of Strain I. 



Habitat: The cacao bean so far as known. 



90. Streptomyces marinus (Humm and 

 Shepard, 1946) Waksman, comb. nov. (Acti- 

 nomyces marinus Humm and Shepard, 

 Duke Univ. Marine Sta. Bull., 3, 1946, 77.) 



ma.ri'nus. L. adj. marinus marine, of the 

 sea. 



Vegetative growth: Mycelium sparingly 

 branched, dense, entangled. Growth on agar 

 moderately rapid, reaching a diameter of 

 one cm or more after about ten days. My- 

 celium frequently forms concentric rings in 

 response to alternate periods of light and 

 darkness. No soluble pigments. 



Aerial mycelium: White; conidia medium 

 gray to dark gray. Aerial hyphae somewhat 

 irregular in diameter, 0.8 to 1.4 microns. 

 Conidia spherical to ellipsoidal, 0.8 to 1.2 

 microns in diameter, in chains, sometimes 

 forming loose spirals. Conidia typically 

 appear after three days as a dark gray area 

 in center of each colony. 



Gelatin: Growth arborescent. Stratiform 



liquefaction, beginning after about ten days 

 at 20° to 23° C. 



Broth: Strong white pellicle. White tufts 

 may develop at sides of tube beneath sur- 

 face of liquid. 



Milk: Alkaline within one week; com- 

 pletely peptonized, usually within one 

 month at 25° to 30° C. 



Indole not produced. Indigotin not pro- 

 duced from indole. 



Hydrogen sulfide vigorously produced. 



Acid from galactose, glucose, fructose, 

 mannose, cellobiose, lactose, maltose, su- 

 crose and glycerol. Arabinose, xylose, rham- 

 nose and sorbitol utilized without acid 

 production. No growth in raffinose, salicin, 

 inulin, dulcitol, inositol, ethyl alcohol or 

 ethylene glycol. 



Acetylmethylcarbinol not produced. 



Starch vigorously hydrolyzed. 



Cellulo.se not hydrolyzed. 



Chitin and alginic acid are attacked. 



Seaweed gells: Agar slowly digested; 

 softened, not liquefied. Growth on agar in 

 culture dish surrounded by rather wide, 

 gently sloping depression. Gelase field rela- 

 tively wide with distinct margin. Irish moss 

 and Hypnea gels also slowly digested. 



Acetic, citric, lactic, propionic, succinic 

 and iso-valeric acids utilized. Butyric, 

 gluconic, maleic, malonic and oxalic acids 

 not utilized. 



Aspartic acid, cystine, glutamic acid, 

 glycine, 1-leucine and tyrosine utilized as 

 sources of both nitrogen and carbon, dl- 

 Alanine and d-arginine utilized only as 

 nitrogen sources. Creatine and dl-/3-phenyl- 

 alanine not utilized. Glucosamine-HCl 

 utilized as source of nitrogen and carbon. 



Ammonia, nitrite or nitrate utilized as 

 nitrogen sources. Ammonia produced from 

 nitrate, asparagine, peptone and glutamic 

 acid. Urea used as nitrogen source with 

 production of small amounts of ammonia. 



Nitrites usually not produced from ni- 

 trates. In some media, slight nitrite is pro- 

 duced after ten days' incubation, especially 

 if glucose is present. 



Catalase-positive. 



Aerobic. 



Optimum temperature, between 25° and 

 30° C. 



Good growth in media prepared with dis- 



