SLIME-FORMING BACTERIA. 143 



Bottled wines suffer more than wine in the cask ; white 

 wines more than red, because the former contain more sugar, 

 especially laevulose, which forms an excellent food-stuff for 

 these ferments. 



Slime-forming bacteria have been isolated from eight 

 different wines, some white and some red, and six of the 

 species were subjected to an exact investigation. They all 

 occur as short rods, varying in length and breadth (1-1 to 

 4- 2 //. long, 0-7 to 1-7 /j. wide). They seldom occur singly, 

 usually linked in chains, which are short and straight in some 

 cases, and in others long and spiral. They are non-motile, 

 anaerobic, neither form spores nor liquefy gelatine, and all 

 give the Gram coloration. They are surrounded by a slimy 

 growth at every stage of development. The optimum tem- 

 perature for propagation lies between 25 and 30 C. 



Bacteria have been found in bread which produce a strong 

 formation of slime, and in particular the "potato bacilli" appear 

 to be active i.e., varieties of Bac. mesentericus wdgatus (Bac. 

 panis viscosi), described by Kratschmer and Niemitowicz, and 

 Toy Uffelmann, Thomann, Vogel, and others. As a consequence 

 of the action of these bacteria the bread can be drawn out 

 into long thin glutinous strings. They occur in rye meal 

 and multiply in presence of moisture. They develop in bread 

 if the spores survive the baking temperature, and the bread 

 is stored in a warm place. According to Migula, Bac. panis 

 (Vogel) occurs in long slender rods (4 to 7 //), forming chains, 

 which have a rapid movement, and possess a polar cilium. 

 They form oval spores, which survive the action of a current 

 of steam at 100 C. for fifteen minutes (in a potato culture). 

 On gelatine plates the colonies form flat liquefied depressions. 

 With a magnification of 70, it appears as a colony having 

 a yellowish-brown nucleus coarsely granulated, and delicate 

 streamers in the gelatine. On agar also the colonies form a 

 nucleus with streamers. The optimum is at 40- 4 2 C. 



In plant infusion (digitalis leaves), Ritsert proved experi- 

 mentally the presence of a Bad. gummosum which brings about 

 a mucilaginous formation of slime. Its activity depends upon 

 the sugar content of the liquid, and is greatly favoured by the 

 presence of potassium and sodium acetate and yeast ash. 



