440 



G. P. PLAISANCE AND B. W. HAMMER 



The per cent of mannitol produced in various materials 



The per cent of mannitol produced in different materials varied 

 widely. While this was due to a large extent to variations in 

 the per cent of total sugar, as well as to variations in the make-up 

 of the sugar in the original materials, differences in the efficiency 

 of the different organisms tried undoubtedly played a very large 

 part. Table 4 presents data, other than those already presented, 

 showing the per cent of mannitol produced under different con- 

 ditions and in various materials. Many other determinations 

 were made only to find out whether mannitol was present in 

 traces or in considerable quantities and the results are of course 

 omitted. 



TABLE 4 



The per cent of mannitol produced under different conditions , room temperature 



incubation 



The destruction of mannitol 



The data already reported by the Iowa station show that, in 

 a silo, part of the mannitol produced is destroyed. Table 5 

 shows the per cent of mannitol present at various times in stover 

 silage containing sucrose inoculated with organism M39 and 

 held at room temperature. A series of silos were prepared and 

 a different one used for each determination. 



From table 5 it seems that, at least with the organism used, the 

 production of mannitol was accompanied or followed by its 

 partial destruction. 



