Stimulation of Growth of Desulfovihrio dcaulfuricans 445 



medium. The amino acids medium without added ATP, however, 

 did not by itself support tlie growth of this microorganism. 



These data revealed that ATP and the eighteen amino acids 

 together could completely be substituted for peptone, in respect 

 to the growth-stimulating activity for this microorganism. 



We attempted next to replace ATP by its possible precursors 

 and some related compounds ( adenosine-5'-monophosphate 

 (AMP), adenosine-3'-monophosphate, adenosine, inosinc, ade- 

 nine, hypoxanthine and guanine) by using a chemically defined 

 medium composed of minerals, lactate, ascorbic acid and eighteen 

 amino acids as the basal. For reference acid-soluble nucleotides 

 preparation from the cells of D. cJcsuIfuricans (Maizuru 1) itself 

 (prepared after Tsuboi and Price (25) ), which was found by 

 paper chromatography (3, 27) to contain ATP, AMP, adenosine- 

 5'-phosphosulfate (APS) and three other unidentified nucleo- 

 tides, was also tested for ability to stimulate the growth in place 

 of ATP. 



By this experiment, the results of which were given in Table 

 2, we found that AMP, adenosine-3'-monophosphate, and the 

 nucleotides preparation from the cells were equally active as ATP 

 in stimulating the growth of D. desidftiricans (Maizuru 1); ATP 

 in this respect was perfectly replaced by the above nucleotides. 



TABLE 2 



Response of D. Desiilfuricans (^Marizuru 1 ) to ATP and its Related Com- 

 pounds IN Chemically Defined Medium 



Supplement Growth, O. D. at 610 mn 



ATP 0.47 



AMP 0.47 



Adenosine-3'-monophosphate 0.47 



Adenosine 0.06 



Inosine 0.03 



Adenine 0.05 



Hypoxanthine 0.06 



Guanine 0.05 

 Nucleotides preparation from 



the cells of Desulfovihrio 



desulfuricans (Maizuru 1) 0.47 



None** 0.05 



** Basal medium contained minerals, lactate, ascorbic acid and eighteen amino 

 acids. 



