MANNITOL-PKODUCING ORGANISMS IN SILAGE 441 



Organisms having mannitol-producing powers 



A considerable number of organisms capable of producing 

 mannitol were isolated from various samples of silage and 

 studied morphologically, culturally, and biochemically. The 

 results showed that the organisms cannot be considered to be 

 of one type. Most of the cultures isolated produced no appre- 

 ciable change in milk and undoubtedly should be classed as 

 Bacillus manniticus of Gayon and Dubourg, but one of the 

 cultures in particular produced a coagulation in litmus milk 

 with an extensive reduction of the litmus and its general charac- 

 teristics indicated that it should be classed as Bad. casei. Cer- 

 tain of the rod-shaped (Kruse 1910; Orla-Jensen 1919) lactic acid 



TABLE 5 



The per cent of mannitol at various times in stover silage containing sucrose and 

 inoculated with organism M39, room temperature incubation 



organisms have been shown by a number of investigators to 

 produce mannitol. With this group of organisms, however, 

 mannitol production is not a general characteristic since a con- 

 siderable number of cultures from sources such as milk, silage 

 and cow feces were examined for mannitol production by inocu- 

 lating into satisfactory media but only with negative results. 



From the findings reported it seems that the production of 

 mannitol in silage is not the result of the action of organisms 

 present in silage alone but is brought about by the activity 

 of organisms that have been shown to produce mannitol in other 

 materials such as wines, etc. The conditions, such as a lack of 

 oxygen and the presence of sugar, existing in silage during the 

 period of active fermentation are undoubtedly very favorable 



