450 Bacteria in Relation to Country Life 



two or more. However, when growing in media contain- 

 ing cane-sugar or grape-sugar, it produces the character- 

 istic gelatinous mucus. The gelatinous envelope serves 

 as a protection to the organism against unfavorable 

 conditions. It enables it to withstand drying for a long 

 time and makes it; resistant to heat. For this reason, 

 it survives in the heated juice, when other bacteria are 

 destroyed, and retains its ability to cause mischief. 



The injury caused by Streptococcus mesenteroides 

 is twofold. It destroys a certain amount of sugar by 

 converting it into mucus, and it produces an enzyme, 

 invertin, which changes cane-sugar into grape-sugar, 

 increasing, thereby, the proportion of molasses. It 

 probably finds its way into the sugar refinery with the 

 raw materials employed, for it may be assumed to occur 

 in the soil. 



Clostridium gelatinosum. — Another organism that 

 is frequently a troublesome pest in the sugar industry is 

 Clostridium gelatinosum. This organism forms resistant 

 spores and is not destroyed when the sugar is heated 

 to from 122° to 158° Fahr. It destroys the sugar with 

 the production of butyric acid and of other substances. 



Similarly, among the large variety of other bacteria 

 found in the raw juice and derived from the air, water, 

 and soil, there are species that produce organic acids and, 

 likewise, large amounts of gaseous products. It is not 

 at all surprising, of course, that bacteria are numerous 

 in the raw juice, for the latter offers an abundant supply 

 of food to most species. The manufacturer of sugar must, 

 therefore, be constantly on his guard against the in- 

 vasion of the raw juice by microorganisms. 



