Streptomyces No. 310 is an antibiotic streptomyces which was isolated by the authors from the soil of Sayama-hill in1949. The antibiotic substance (No. 310 substance) produced by this organism crystallizes from acetone in rhombic form; d. p. 228_??_230°, elemental analysis (Found: C 51.49, H 5.06, N 4.94, Cl 13.15), antibacterial spectrum and toxicity of this substance show that No. 310 substance is identical with aureomycin monohydi-ochloride⁽³⁾⁽⁴⁾. After the taxonomic studies on Streptomyces No. 310, the authors recognized that Streptomyces No. 310 was different from Streptomyces aureofaciens; an aureomycin producing strain which was reported by B. M. DUGGAR in 1948⁽³⁾⁽⁵⁾. Streptomyces No 310 is easily differentiated from Streptomyces aureofaciens in the following points; the conidium of S. No. 310 is short rod to short, cylindrical in intact form, and when stained with PFEIFFER's method it is right prism to cube-shaped having slightly rounded corner, about 1.0 by 1.5 microns, on the other hand the conidium of S. aureofacieas is spheroidal to oval. (Table 4). On the potato plug S. No. 310 showes heavy growth, pinkish gray with purplish tinge, pale reddish brown soluble pigment formed, rugous and potato darkened after long time, while S. aureofaciens does not formed soluble pigment and not darkened potato. (Table 4). The culture of litmus milk; S. No. 310 shower yellowish gray collar, coagulation and peptonization with alkaline reaction, while S. aureofaciens showes yellow-brown above, neither significant pH change nor apparent peptonization in 15 days (Table 4). After the analytical comparisons of chemical changes in l0% skim-milk powder medium, S. No. 310 is different from S. aureofaciens in the surveys of total N and NH₃-N in centrifuged culture medium, redoxpotential and pH; EhmV of S. No. 310 broth in 6 days is +107.2 mV at pH 6.6, 37° while +163.2 mV at pH 6.2, 37°, in S. aureofaciens. On 12 th day S. aureofaciens showes higher potential than S. No. 310. pH of S. No. 310 broth on 17th day culture is pH 8.2 and that of S. aureofariens is pH 5.8. The observation on total N and NH₃-N of the two strains. is different as Fig. 3.
According to the T. G. PRIDHAM's method⁽⁷⁾, S. No. 310 cannot utilize xylose, arabinose and lactose, while S. aureofaciens utilizes these three carbohydrates.
In the description of BERGEY'S Manual of Determinative Bacteriology (1949), S. No. 310 is only somewhat related to S. flavovirens but it is differenciated from this species by the color of soluble pigment, and on the culture of gelatin stab; S. No. 310 does not liquefy gelatin (Table 3).
Hence, the authors designated this strain as Streptomyces sayamaensis n. sp. after the name of the place, whence this organism has been isolated.