abstracts: bacteriology 229 



BACTERIOLOGY. — The preparation of dried cidtures. L. A. Rogers. 

 Journal of Infectious Diseases 14: 100-123. January, 1914, 

 This paper discusses the preparation of dried cultures of bacteria 

 of various kinds by a method adapted from that first proposed by 

 Shackell. The method consists essentially in holding the previously 

 frozen culture over sulphuric acid in a container in which a vacuum 

 of a few hundredths of a millimeter is maintained. Cultures of Strep- 

 tococci, B. bidgaricus, and similar organisms, when dried by this method 

 are much more active than when dried by the usual methods in an air 

 blast. The length of time that the dried culture remains active is in a 

 general way inversely proportional to the amount of moisture present 

 and the temperature at which it is held. Cultures deteriorate much 

 more rapidly in air or oxygen than in an inert gas, such as hydrogen or 

 nitrogen. The best results were obtained with cultures held in a vacuum. 

 Dried cultures held in evacuated tubes at a temperature below freez- 

 ing deteriorated very slowly. L. A. R. 



BACTERIOLOGY. — Bacteriology of cheese of the Emmenthal type. 

 E. E. Eldredge and L. A. Rogers. Centralblatt f . Bakteriologie 

 40-: 5-21. February 16, 1914. 



The bacterial flora of domestic Emmental cheese consists for the most 

 part of bacilli which may be classed with the so-called Bacillus bidgari- 

 cus. Cocci were present in small numbers at one stage of the ripening. 

 There was a progressive change in the flora as the cheese ripened, in that 

 one morphological type which predominated in the beginning was gradu- 

 ally replaced by another. In one cheese the proprionic bacteria, which 

 according to Jensen supply gas for the eye formation by fermenting cal- 

 cium lactate, were found by special methods in comparatively small 

 numbers. 



It has been shown in a previous investigation that the gas inflating 

 the eyes is carbon dioxide, and in this work it was found that certain 

 cultures were able to produce carbon dioxide from milk from which the 

 sugar had been removed by fermentation. Without inoculation of 

 some kind it is impossible to make normal Emmental cheese outside the 

 restricted area in which it has been made for years. This may be 

 accomplished by using a mixed culture obtained by adding a small 

 amount of good cheese to sterile whey. It has also been accomplished 

 in a few preliminary experiments with pure cultures isolated from good 

 cheese. L. A. R. 



