244 



BACTERIOLOGICAL CHEMISTRY 



CHO 

 H.C.OH 

 HO.C.H 



H.C.OH 



I 

 H.C.OH 



I 

 CH2O: 



(glucose) 



COOH 



I 

 H.C.OH 



I 

 HO.C.H 



I 

 H.C.OH 



H.C.OH 



I 

 CH2OH 



(gluconic acid) 



COOH 



i 

 H.C.OH 



I 

 HO.C.H 



H.C.OH 



H.C.OH 



I 

 CHO 



(«-aIdehydo- 

 i^-gluconic acid) 



CHO 



I 

 HO.C.H 



I 

 HO.C.H 



H.C.OH 



HO.C.H 



I 

 COOH 



(i-gularonic 

 acid) 



Bad. gluconicwm, in neutral solution in presence of cal- 

 cium carbonate, was also found to oxidise gluconic acid 

 to 2-ketogluconic acid, which is in contradiction of 

 Bert rand's rule, since the two hydroxyl groups are in 

 the tmns--positioii : — 



COOH 



H.C.OH 



I 

 HO.C.H > 



I 

 H.C.OH 



H.C.OH 



I 

 (^HoOH 



COOH 

 CO 

 HO.C.H 

 H.C.OH 

 H.C.OH 



Two 2^t>ints should be noticed, however ; first, that a 

 different organism is involved and second, that a carboxyl 

 and not a primary alcohol group is adjacent. 



Like A. xylinum, Bad. gluconicmn and Bad. 

 xylinoides oxidise sorbitol to /-sorbose, the yields being 

 59, 76 and 60 per cent, respectively. A. xylinmn is used 

 commercially in the production of ascorbic acid to convert 

 sorbitol, obtained l)y the reduction of glucose, into 

 /-sorbose, which is oxidised to 2-keto-/-gulonic acid whose 

 iiKithyl est(uv is readily transformed to ascorbic acid: — 



