THE KINDS OF MICRO-ORGANISMS IN MILK 



383 



find that the cultures that gave evidence of the most intense vis- 

 cosity contained as much acid as those that had the least vis- 

 cosity. Sliminess was not reduced by holding cultures at 37° C. 



< 



\ 



r 



X 





Fig. 179. — Streptoeoccii.s lactifiis, from first transfer of a commercial 

 starter culture. Capsule stain. It will be noted that some chains of organ- 

 isms are capsulated, others are not capsulated. (R. E. Buchanan and B. W. 

 Hammer in Research Bull. No. 22, Iowa State College of Agriculture.) 



or by transferring them frecjuently and incubating at the same 

 temperature. 



While Streptococcus lacticus and Bacillus aerogenes are fre- 

 quently the cause of slimy milk, the organism most commonly 



^f-^' 



Fig. ISO. — Streptococcus lacticus, Fig. ISl. — Streptococcus lacticus, 



occurring in long chains in a starter capsulated chains from a slimy com- 

 from which sliminess has disappeared. mercial starter cvilture. 

 (R. E. Buchanan and B. W. Hammer in Research Bull. No. 22, Iowa State 

 College of Agriculture.) 



responsible is B. (lactis) viscosus, first described by Adametz. 

 This organism grows preferably at low temperature, as low as the 

 temperature of a house refrigerator. Ward was able to recover 

 it from water, ice, and the stable air, and believes, with other 

 investigators, that surface waters are frequently inhabited by this 



