156 MICRO-ORGANISMS AND FERMENTATION. 



diseases. The name " Sarcina disease " is best retained, as 

 certain conceptions are associated with it.* 



Lindner has described a number of Sarcina species in 

 pure cultures, and amongst them one which occurs in diseased 

 lager beer, which he named after Balcke, Pediococcus cerevisicR. 

 It grows best with access of air, and forms yellowish or 

 3 r ello wish-brown colonies on meat- juice gelatine, which is not 

 liquefied. In a stab-culture it gives a flat white colony on 

 the surface. In the streak culture it forms a greyish-white 

 moist line, which appears iridescent in thin layers. On meat- 

 juice gelatine it is killed by eight minutes' exposure to 

 60 C., but not by twelve minutes' exposure at 50-55 C. It 

 proved impossible by inoculating pure cultures to reproduce 

 the unpleasant flavour and odour of the beer ; only turbidity 

 ensued, and the isolated species doubtless cannot have been 

 .a disease Sarcina. 



In later experiments Lindner succeeded in a few cases in 

 reproducing the characteristic appearance in beer by the 

 application of yeast which had been inoculated with a Sarcina 

 isolated from the diseased beer. On the other hand, A. 

 Petersen observed a case where a growth of these organisms had 

 developed in beer without affecting either its flavour or its smell. 



A. Reichard isolated from low-fermentation beer a Pedio- 

 coccus sarcinceformis, which developed freely in sweet wort 

 and sterile beer, but not in pasteurised beer. This species 

 developed best when access of air was limited. In ferment- 

 ation experiments turbidity or peculiar changes of taste 

 occurred in certain cases, but not in the majority. After many 

 experiments, he arrived at the conclusion that these contrary 

 results were due partly to the condition of the various growths 

 of this Sarcina form, partly also to the manner in which the 

 fermentation took place. In cases of quiet fermentation in 



* As examples of the various typical Pediococcus = Micrococcus species, may 

 be instanced M. candidus and concentricus growing in water ; M. urece, which 

 converts urine into ammonium carbonate, and M. lacticus, which Marpmann 

 found in fresh milk, giving white and non -liquefying colonies ; M. amarifi.ca.ns, 

 which, according to Conn, makes milk bitter, and M. casei amari, which, according 

 to Freudenreich, makes both milk and cheese bitter: these have white liquefying 

 colonies ; M. luteu-s with yellow non-liquefying, and M. ftavus with yellow lique- 

 fying colonies ; M. cinnabarium and carneus, isolated from water, with red colonies. 



