Supplemental Notes 



By Joan F. Powell 



Effect of manganese on sporulation of laboratory strains 

 of Bacillus cereus, B. subtilis and B. megatherium 



The effect of glucose (lO'M) and manganese (10 ^M) addition on sporu- 

 lation in shaken tryptic meat digest medium (100 mg nitrogen/100 ml) was 

 tested. All the above organisms grew well but showed no signs of sporula- 

 tion in the test medium with no additions or with added glucose. 



Manganese addition stimulated almost complete sporulation of B. cereus 

 in the presence but not in the absence of glucose, of B. subtilis in the ab- 

 sence but not in the presence of glucose, and of B. megatlierium both in 

 the presence and absence of glucose. These results were not always repeat- 

 able with different batches of meat digest medium prepared in an identical 

 manner and of equivalent nitrogen content. For example, in four other 

 batches of medium, only in one batch was sporulation of B. cereus stimu- 

 lated by addition of manganese and glucose. In all batches of medium 

 tested, B. sphaericus sporulated well in the absence of any additions. 



Oxidations catalyzed by spores of B. subtilis (laboratory strain 

 and NCTC 85) and B. megatherium (laboratory strain) 



Resting spores of B. subtilis and B. megatherium tested intact and me- 

 chanically disintegrated catalyzed the oxidation of p-phenylenediamine (Qo._, 

 37° =^ 60) and hydroquinone (Qo., 25° ^ 30). There was no stimulation 

 of this oxidation by added cytochrome C. The oxidation catalyst of B. sub- 

 tilis was unaffected by heating at 60° for 15 min. whereas that of B. mega- 

 therium was 75% destroyed. Tlie B. megatherium catalyst also differed from 

 that of B. subtilis in its comparative insensitivity to low concentrations of 

 cyanide. Thus, with p-phenylenediamine substrate, the B. subtilis catalyst 

 was 45% and 67% inhibited by 10"^ and 2 x 10-' M. KCN, whereas 

 that of B. megatherium was unaffected by lO^M.KCN although 95% inhib- 

 ited by 2 X 10-%I.KCN. The nature of the oxidation catalysis is still ob- 

 scure: it seems likely that contamination with invisible vegetative debris 

 would account for the heat-labile catalysis of B. megatherium spores. 



Further tests were made with spores of B. subtilis. These spores showed 

 no .phange in oxidative activity after germination in L-alanine, and the cat- 

 alyst remained heat-stable. B. subtilis spores also catalyzed the oxidation of 

 ascorbic acid and of reduced sytrochrome C. To follow oxidation of the latter 



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