2l8 



ness. Tartrates, citrates, succinates, glycolates, salts of volatile acids, and sugars do 

 not give the reaction. 



The experiment may be modified in different ways, for example, by using instead 

 of broth agar a culture medium of the composition: 100 tapwater, i calciummalate, 

 0,1 ammoniumsulfate, 0.02 potassiumfosfate, with some ferric citrate as an indicator, 

 and furthermore treated as above. The less favourable source of nitrogen is cause 

 that on such a medium a smaller number of species of bacteria grow, but the reaction 

 is as distinct, and the proportion of the active to the non-active germs on the am- 

 moniacal medium even greater than on the broth-agar plate. 



The species that cause the conversion may be arranged in the following order 

 according to their intensity of action. 



The most vigorous splitters are B. fiuorescens, B. ft. liquefaciens, B. calco- 

 aceticus and B. pyocyaneus. Then follow B. aerogenes, B. viscosus and B. levans, 

 and some varieties of B. violaceus. 



A little less active are B. coli, B. proteus, B. prodigiosus, B, kieliensis, and the 

 vinegar bacterium Acetobacter rancens. Quite inactive are B. termo, B. punctatus, 

 B. devorans, B. ochraceus, and the luminous bacteria; nearly inactive are the vinegar 

 bacteria Ac. melanogenum, and Ac. pastenrianum. 



Nor do the moulds and yeasts examined up to now produce pyruvic acid, although 

 many of them readily oxidise the malates to carbonic acid and water. 



As some bacteria such as B. pyocyaneus, B. aerogenes, B. levans, B. viscosus 

 and some moulds and yeasts are able also to oxidise the pyruvates themselves to 

 carbonate and water, one might suppose that the species which appear not to produce 

 pyruvic acid from malic acid, in fact do so, but only as a transition product, but 

 what follows is in contradiction with this supposition. First, the pyruvates are less 

 readily attacked than the malates, so that accumulation and not oxidation of the 

 pyruvates would become probable. Secondly experiments prove that the ferric salt 

 solution enters the microbic cells. As now the oxidation of the pyruvates like that 

 of the malates undoubtedly takes place in the interior of these organisms, the pre- 

 sence of the pyruvic acid ought to cause a colouring of them, which is not observed. 



With the active microbes the reaction is caused by a certain portion of the 

 living protoplasm, or in other words, by an endoenzyme or an endooxidase, to which 

 the name of malopyruvase might be given. It belongs to the complex of the different 

 endoenzymes which together govern the respiration function, of which it is one of 

 the factors in Mendelian sense. 



From the levogyric or common malic acid and the inactive malic acid pyruvic 

 acid results with the same readiness; from the dextrogyric malic acid, which we 

 owed to Prof. Blanksma, it is produced with much more difficulty. 



The said microbes which produce pyruvic acid from the malic acids do the same 

 from fumaric acid: 



C4H 4 O 4 + O = CgHiOa + CO 2 



but not from maleinic acid. We used fumaric acid as lime salt, prepared from the free 

 fumaric acid after its purification by washing with water. Hence, malate of lime was 

 not present in our fumarate. 



