KLUYVER S CONTRIBUTIONS TO MICROBIOLOGY AND BIOCHEMISTRY 



substrate is oxidized with the concomitant reduction of another, ac- 

 cording to the equation : 



2C 3 H 8 3 -» C 3 H 6 3 +C 3 H 8 2 +H 2 



An essentially similar situation was encountered some years later when 

 Barker [1936b, 1937a], during his sojourn in the Delft institute, stud- 

 ied the fermentation of malic, fumaric, and tartaric acids by bacteria 

 of the coli-aerogenes group, and of glutamic acid by anaerobic spore- 

 forming bacteria. Here, too, comparable initial conversions, such as 



2 C 4 H 6 5 -> C 4 H 4 5 +C 4 H 6 4 +H 2 



could be invoked to explain the accumulation of succinic acid, and of 

 other products by a further degradation of oxaloacetic acid through 

 pyruvic acid. 



The fermentation of the methyl pentose, rhamnose, by B. rham- 

 nosifermentans provides a good example of the ready applicability of 

 the theory to another aberrant type of metabolism. Kluyver and 

 Schnellen [1937] found that in this fermentation 1,2-propane diol is 

 formed in an amount approximately corresponding to one mole per 

 mole of rhamnose fermented. Apart from an indication in an earlier 

 report that it may be produced in small quantities during the commer- 

 cial manufacture of glycerol by fermentation of sugar in the presence 

 of sulphite, this was the first, and so far the only record of the appear- 

 ance of the asymmetrical propane diol as a major metabolic end prod- 

 uct. Its formation was explained by postulating a rupture of rham- 

 nose to lactic and glyceric aldehydes, the former acting as the virtu- 

 ally exclusive hydrogen acceptor for those reactions by which the 

 glyceraldehyde is further degraded. The formation of succinic acid, 

 which was found in considerable quantities in this fermentation, was, 

 as in the previous studies of Braak [1928Tb] and Scheffer [1928TI1] 

 on fermentations by members of the coli-aerogenes group, attributed 

 to a cleavage of hexose into a two- and a four-carbon fragment ; the 

 hexose was assumed to be generated by a condensation of two mole- 

 cules of glyceraldehyde. A somewhat more detailed discussion of this 

 aspect will be found in a later section of this chapter. 



Not less fruitful than in the above-mentioned cases was the applica- 

 tion of the theory to those metabolic phenomena that can best be 



"5 



