70 MICRO-ORGANISMS IN WATER 



The following table of results is taken from a recent 

 paper by Holm ^ : — 



Water No. 1 



i Gelatine -peptone yielded about 8,000 colonies per c.c. 

 (Mostly bacteria.) 

 Gelatine to which wort had been added yielded about 14 

 colonies per c.c. (Moulds.) 



I Sterilised wort yielded about 5*4 colonies per c.c. 

 (Bacteria and moulds.) 

 Sterilised beer yielded about 0*8 colonies per c.c. 

 (Moulds.) 

 Water No. 2 



I Gelatine-peptone yielded about 350 colonies per c.c. 

 (Bacteria.) 

 Wort-gelatine yielded about 8 colonies per c.c. 

 (Moulds.) 

 ( Sterihsed wort yielded about 5*3 colonies per c.c. 

 Liquid ' (Bacteria and moulds.) 



cultures I Sterilised beer yielded about 0'8 colonies per c.c, 



I (Moulds.) 



Water No, 3 



( Gelatine-peptone yielded about 370 colonies per c.c. 

 Plate 1 (Bacteria.) 



cultures Wort-gelatine yielded about 4 colonies per c.c. 



^ (Bacteria.) 



I Sterilised wort yielded about I'l colonies per c.c. 

 (Moulds and Torula (yeast).) 

 Sterilised beer yielded about 0*4 colonies per c.c. 

 (Moulds.) 



Thus, in the case of the last water, the wort and 

 beer revealed the presence of totally different organisms 

 from those which made their appearance on the gela- 

 tine plate-cultures. It was pointed out by Hansen that 

 the great practical utility of the substitution of steri- 

 lised wort and beer for gelatine media is that some 

 organisms, which, from the brewer's point of view, it is 



^ * Analyses biologiques et zymotechniques de Teau destin^e aux 

 brasseries,' Compte-rendu des travaux du lahoratoire de Carlsberg, vol. 

 iii. livraison 2. Copenhagen, 1892. See also ' Sur les methodes de culture 

 pure et, sp^cialement, sur la culture sur plaques de M. Koch et la limite 

 des erreurs de cette methode,' loc. cit. vol. iii., hvraison 1. 1891. 



