OXIDATIVE ENZYMES OF BACTERIAL SI»OI{E EXTRACTS 15?, 



HCOH Q=0 



HOCH '^gOg HO9H 



H9OH fPN * HCOH 



HQOH HQOH 



CHgOH CHgOH 



Gluconic Acid 2-keto gluconote 



Fig. 11. Oxidation of gluconic acid. 



II) similar to the inducible 2-ketogluconokinase found in Aerobacter cloa- 

 cae by DeLey (1953) and P. fluorescens by Narrod and Wood (1954). The 

 reaction is shown in Fig. 12. The involvement of ATP in this reaction mav 

 be the explanation for the phosphate stimulation of glucose oxidation pre- 

 viously observed in dialyzed extracts. The reactions leading to pyruvate for- 

 mation from 2K6PG are little understood. Wood (1955) has suggested that 

 this may occur in P. fluorescens via dehydration and cleavage reactions for 

 2-K6PG of the Entner-Doudoroff type leading to 2. 4 diketo-3-desoxv-6 phos- 

 phoguconate. which is cleaved to pyruvate and 3-phosphoglvcerate. 



Pyruvate oxidation 



The metabolism of trioses represents the second phase of oxidative activ- 

 ity of spore extracts. The presence of a system leading to pyruvate from 

 glucose as well as the oxidation of pyruvate (see Fig. 4) provides a basis 



Table II 



The stoichiometry of 2-keto gluconate phosphorylation 



by spore extracts of B. cereus var. terminalis 



The incubation mixture contained 1 ml of spore extract, 0.2 ml of 0.05 M 

 AT^, 1 ml of 2-keto gluconate, 0.008 M MgClo and sufficient 0.1 M glycyl- 

 glycene buffer pH 7.4 to give a final volume of 2.0 ml. After 20 minutes 

 incubation at 30C the reaction was deproteinized and anahzed for 2- 

 ketogluconate and acid-labile and acid-stable P. 



