Pigments as products of oxidation by bacterial 



action. 



Proceedings of the Section of Sciences, Kon. Akademie van Wetenschappen, Amster- 

 dam, Vol. XIII, 1911, p. 1066 1077. Verscheen onder den titel Pigmenten als oxydatie- 

 producten door bakterien gevormd in Verslagen Kon. Akademie van Wetenschappen, 

 Wis-en Natuurk. Afd., Amsterdam, Deel XIX, 1911, biz. 1092 1103; e " onder den titel 

 />Ueber Pigmentbildung bei Essigbakterien in Centralblatt fur Bakteriologie und Para- 

 sitenkunde Jena, II. Abteilung, XXIX. Band, 1911, S. 169 176. 



T 



he following experiments make it possible easily to find some notable bacteria 

 more or less common in our surroundings and partly not observed hitherto. 



i. Formation of Protocatechetic acid from Chinic acid. 



As Low 1 ) had shown that i proc. solutions of calcium chinate become brown 

 when exposed to the air by the formation of protocatechetic acid, Emmerling 

 and Abderhalden 2 ) have investigated this biochemism bacteriologically. They 

 neutralised 10 proc. solutions of chinic acid with calcium carbonate, added 0.5 proc. 

 peptone, o.i proc. kalium phosphate, and o.i proc. magnesium phosphate, inoculated 

 this mixture with a few drops of an infusion of putrefying meat, and cultivated for 

 some weeks at 35 C. They obtained protocatechetic acid together with a slimy bac- 

 terial mass in the liquid, from which it was possible to isolate a likewise slimy 

 Micrococcus, which proved to be the cause of the production of the latter acid and 

 was named M. chinicus. 



The reaction goes after the formula: 



C 7 H 12 O 6 + O = C 7 H 6 O 4 + 3 H 2 O 

 Chinic acid Protocatechetic acid 



whereby at most 12 proc. chinic acid is converted; into what the remaining 88 proc. 

 change is not noted by these experimenters. It is remarkable that only one atom of 

 oxygen takes part in this reaction. 



*) Berichte der Deutschen Chem. Gesellschaft, Bd. 14, pag. 450, 1902. 

 '-) Ueber einen Chinasaure in Protocatechusaure iiberfiihrenden Pilz. Centralblatt 

 fur Bakteriol. 2te Abt. Bd. 10, pag. 337, 1903. 



M. W. Beijerinck, Verzamelde Geschriften ; Vijfde Deel. I 



