Genus Betacoccus (Abbr. Bc). 



As mentioned in the introduction to tlie streptococci, the betacocci are found in green 

 vegetable matter and juicy roots. They are as widely distributed in beets as the sacrharo- 

 myces on sweet and juicy fruits. They are introduced with vegetable food into the intes- 

 tinal canal of animals, and pass thence into the milk. In the retting process we always 

 encounter arabinose-fermenting betacocci, which might be connected with the fact that 

 pectin substances always contain an arabinose groupé). As thesebacteriacanmake vegetable 

 matter tender, e. g. sour cabbage, it is possible that they play some part in the retting 

 process itself; this point, however, we have not yet been able to elucidate thoroughly. 

 As the betacocci are far more variable in all respects than the streptococci, it is very dif- 

 ficult to divide them up into clearly defined species, and I therefore prefer to treat the 

 genus Bdacoccus under one head, and merely note in conclusion what features might seem 

 to justify our uniting certain strains into independent species. In Tables XXV a and b and 

 XXVI, they are arranged principally according to their relation to the pentoses. 



The betacocci can as a rule stand heating to 60°, but rarely to 65°. In a slimy state, 

 however, they can stand higher temperatures, as the slime protects them, and it has been 

 observed at sugar factories that thin syrup which had been heated to 80° — -85°, and 

 could not possibly have become infected afterwards, has grown slimy (No. 11 has formed 

 zoogloea masses under such conditions). The optimal temperature lies at about30° or under, 

 a single strain (No. 14) was even found to grow best at indoor temperature, and this 

 temperature is, as in the case of Sc. cremoris, the most favourable one for slime forma- 

 tion. The maximal temperature is 35° — 37° (rarely 40°) and the minimal 5° — 7°. Some 

 few strains (Nos. 1, 45,46 and 47) grow, however, at 45°, but on the other hand thrive 

 but poorly below 15°. 



The betacocci always form lævo-lactic acid, more rarely also equivalent quantities 

 of dextro-lactic acid, so that We find inactive lactic acid (Nos. 43 — 47). As certain strains 

 <Nos. 6, 41 and 42) in a freshly isolated state formed inactive lactic acid, and later only 

 lævo-lactic acid, this is evidently a variable quality, which cannot be used by itself as a 

 species character. The betacocci also as a rule develop gas, (carbonic acid with more or 

 less hydrogen). The gas development is strongest in lævulose solutions, and next in cane 



*) Felix Ehrlich: Cliem. Zeitung 1917, 41, p 197. 



