66 CLARENCE F. SCHMIDT 



pletely in the presence of M/180 ethylene diamine tetraacetic acid. It ap- 

 peared that EDTA was acting solely as a chelating agent. It is interesting to 

 note that at concentrations of EDTA above M/10 no germination occurred. 



In summary, there appear to be three general systems for the germination 

 of spores. The most common system is one containing an amino acid, usually 

 L-alanine, a riboside, and occasionally glucose. In some instances, more than 

 one amino acid is required. A second system which has been reported fre- 

 quently is one in which glucose or another energy yielding carbon source, in 

 the absence of any nitrogen source, is sufficient for germination. The third 

 method requires only the presence of the proper concentration of a chelating 

 agent. Heat activation appears to be either stimulatory or makes the germi- 

 nation requirements simpler in most aerobic spores and in some anaerobic 

 spores. It is not possible to say whether the three generalized systems out- 

 lined here are really different or not, since we have not as yet been able to 

 ascertain the function of these stimulants in the germination process. 



The literature regarding germination inhibitors is not extensive. Foster 

 and Wynne (1948) found that unsaturated fatty acids inhibited germination 

 of anaerobic spores. Roth and Halvorson ( 1952 ) reported that this inhibi- 

 tion occurred only when the fatty acids were rancid, and implicated peroxides 

 as the active agents. Powell (1950) found that oxine (lOmM) and 2,3-di- 

 mercaptopropanol ( BAL I ( lOmM ) completely inhibited germination of B. 

 suhtilis spores. BAL inhibition could be partially overcome by soluble salts 

 of Zn, Mg, Cu, or Fe. Exposure to HgCl2 (5%) also caused complete inhibi- 

 tion which could be partially reversed by L-alanine and glucose. Powell 

 (1951) reported that typical respiratory enzymes inhibitors such as NaF. 

 cyanide, 2,4-dinitrophenol, and iodoacetate had no inhibitory effect on 

 germination. On the other hand, Heiligman et al (1956b) found that 2,4- 

 DNP caused essentially complete inhibition and azide, NaF, lOAc, arsenate 

 and arsenite caused at least partial inhibition. Malonic acid, however, did 

 not inhibit the stimulatory action of citric or succinic acids. Hachisuka et al 

 (1956) reported that NaHCOy and Na^COa inhibited germination of B. 

 subtilis spores. Hills ( 1949 ) found that glycine, DL-methionine, DL-cysteine, 

 or DL-valine at relatively high concentrations inhibited the action of L-alanine. 



The most consistent inhibitory action reported is that of D-alanine inhibit- 

 ing the action of L-alanine. Even this has exceptions, however, since Lawrence 

 (1956) reported that when spores were heated in the presence of the sub- 

 strates, D-alanine could replace L-alanine as a germination stimulant for B. 

 cereus var. terminatis spores. 



References 



Amaha, M. 1956. Unpublished data. 

 Brown, W. L. 1956. Unpublished data. 



