MANNITOL-PRODUCING ORGANISMS IN SILAGE 



433 



and was not secured in '' antiseptic" silage made by adding ether 

 to corn, it seemed desirable to repeat and extend these experi- 

 ments in order to confirm the relationship of organisms to 

 mannitol production. The inoculation of sterilized corn or 

 stover silos with a bit of normal silage gave mannitol production 

 regularly. The lack of mannitol in corn silos treated with 

 various chemicals and held at room temperature for periods 

 that gave mannitol with the untreated corn is shown in table 1. 

 When silage from the silos to which the various chemicals 

 had been added was examined under the microscope a very few 

 lightly stained bacteria were the only microorganisms observed 

 and these, in all probability, represented organisms that were 



present on the corn at the time the silos were filled. The normal 

 silage on the other hand showed very large numbers of well 

 stained bacterial and yeast cells and thus presented a very dif- 

 ferent picture than the treated silage. When these statements 

 are compared with table 1 it is evident that when microorganisms 

 developed normally mannitol was produced, while when the 

 growth of microorganisms was prevented by various chemicals 

 no mannitol was formed. 



The isolation of mannitol-producing organisms 



The isolation of organisms capable of producing mannitol was 

 attempted by plating out samples of silage on corn juice or 

 stover juice agar. Representative organisms developing on 

 the plates were grown on agar slopes (usually the same agar as 



