DECOMPOSITION OF NON-NITROGENOUS ORGANIC MATTER 467 



Just as glucuronic acid in the animal body, gluconic acid is the first 

 product in the decomposition of glucose by fungi. 125 Asp. niger pro- 

 duced both gluconic (C 6 Hi 2 7 ) and citric acids (C 6 H 8 7 ) from glu- 

 cose, the latter being formed in more acid and the former in less acid 

 media; neither is intermediary to the formation of the other; both are 

 decomposed further to oxalic acid (C 2 H 2 4 -2H 2 0). The presence of 

 CaC0 3 in the medium will favor the formation of gluconic acid; its 

 absence or a high acidity of the medium will favor the formation of 

 citric acid. Out of 215 gm. of sugar decomposed (in 1200 cc. of me- 

 dium containing 0.15 per cent NH 4 N0 3 ), there were formed 19 grams of 

 fungus mycelium, 63.7 grams gluconic acid, 57.3 grams citric acid and 

 24.2 grams oxalic acid. 126 



According to Aubel, 127 hexoses are acted upon by Bad. pyocyaneum 

 in the following manner: 



alcohol 

 /* 

 Hexose — + methylglyoxal — * pyruvic acid — > acetaldehyde 



\ . ., 

 I acetic acid 



acetic acid -f- formic aldehyde — > formic acid 



Bad. coli changes glucose to ethyl alcohol, lactic and acetic acids, 

 C0 2 and H 2 . 



2 C 6 H 12 6 + H 2 = 2 C 3 H 6 3 4- C 2 H 4 2 4- C 2 H 6 OH + H 2 4- 2 C0 2 



As an instance of the chemistry of decomposition of starch or sugar 

 under anaerobic conditions, it is sufficient to illustrate the action of 

 Bac. acetoethylicujn. 12 * 



CeHiuOe 



I 

 H 2 + C0 2 + CH 3 • COH «- H 2 4- CH 3 • CO • COOH + H 2 -> CH 3 • CHOH • COOH 



+ H 2 



CH 3 • CH 2 • OH CH 3 • COOH 4- H • COOH 



126 Falck, R., and Kiuyma, B. Methodisches und Prinzipielles zur Darstel- 

 lung organischer Sauren auf biologischen Wege mit Hilfe von Fadenpilzen. 

 Ber. deut. chem. Gesell., 57: 915-920, 920-923. 1924. 



126 Butkewitsch, W. tlber die Bildung der Glukon-und Citronsaure in den 

 Pilzkulturen auf Zucker. Biochem. Ztschr., 154: 177-190. 1924; Jahrb. wiss. 

 Bot., 64: 636-650. 1925. See also Berhauer, K. Zum Problem der Saurebildung 

 durch Aspergillus niger. Ibid., 153: 517-521. 1924. 



127 Aubel, E. Attaque du glucose et du levulose par le bacille pyocyanique. 

 Compt. Rend. Acad. Sci., 175: 1493-1495. 1921. 



128 Northrop, J. H., Ashe, L. H., and Senior, J. K. Biochemistry of Bacillus 

 acetoethylicum with reference to the formation of acetone. Jour. Biol. Chem., 



