152 



HARLYN HALVORSON 



CHO 



HCOH 



HO9H 



H9OH 



H9OH 



DPN 



DPNH + H + 

 glucose 

 CHjOH dehydrogenase CHgOH 



C-O" 

 HCOH 

 HOCH 

 HCOH 

 HCOH 



Glucose 



Gluconic Acid 



Fig. 9. Direct oxidation of glucose. 



linked 6-P-G oxidizing system are present, they are not functional due to 

 an absence of hexokinase activity. Although the mechanism of 6-P-G oxida- 

 tion has not been studied, an analysis of the end products indicates that 

 pentose is one of the end products. On the other hand, vegetative cells of 

 members of the family of the Bacillaceae contain all of the enzymes of the 

 HMP system up to the stage of sedoheptulose phosphate formation ( DeLey. 

 1955). 



Activated spores and extracts readily oxidize both gluconate and 2KG. 

 The chromatographic analysis of glucose oxidation ( Fig. 7 ) indicates that 

 gluconate is converted to 2KG, as shown in Fig. 11. Alternatively one might 

 expect a phosphorylation of gluconate via gluconokinase. However, a careful 

 analysis of gluconokinase activity in these extracts by the method of Brody 

 (1955) was negative. 



2KG is phosphorylated by a typical magnesium-requiring kinase I Table 



9H 

 HC — 



HCOH 



TPN 



HOCH 0' 



-OH T T-PNH 



'. 9 



; c — 



', HCOH 



!hoch 



HC ' 



H' 



' HCOH 

 G-6-P ; HC — 



J^gC-OPOj dehydrogenase ] HgC-OPOjl 



L- _ J 



^OH 



OH 



Glucose-6-PO>, 



6-P04Sgiucono- 

 loctone 



HCOH 

 -HOCH 

 HCOH 

 HCOH 

 H2C-OPOJ 



6-PO4- gluconate 



Fig. 10. Oxidation of glucose-6-phosphate. 



