414 SUMMARY OF CURRENT RESEARCHES RELATING TO 



on agar, these colonies were large and watery. Glucose was rendered 

 acid in 48 hours, mannite and lactose in 5 days. No gas was formed. 

 No fermentation of dulcite was observed. 



New Iron-Bacterium.* — E. M. Mumford describes a new iron- 

 bacterium found at the Bridgwater Canal tunnel at Worsley, in 

 Lancashire. The walls of the basin, as well as the grass and trees 

 dipping into the water, were covered with a thick, reddish yellow 

 growth, resembling an aggregation of Gfcnoihrix or Cladothrix. Further 

 examination, however, showed the presence of a motile, ciliated, 

 sporing bacillus, capable of life under aerobic aud anaerobic conditions. 

 Under aerobic conditions, the organism precipitates ferric hydroxide 

 from iron solutions. The anaerobic action is to transform the ferric 

 hydroxide so precipitated into bog ore, with partial reduction of the 

 iron to a ferrous state. 



Bacteriology of Cheddar Cheese. f — E. G. Hastings, Alice C. Evans, 

 and E. B. Hart, have made a systematic investigation of the micro- 

 organisms present in this cheese, with particular reference to their 

 physiological properties and the part they play in the ripening of the 

 cheese. They find that in the normal process of ripening there is a 

 definite sequence in the development of the bacterial groups. At 

 first the Bacterium lactis acidi is the predominant form. This organism 

 prevents the growth of putrefactive bacteria. It activates the pepsin 

 of the rennet extract and favours the curdling of milk by rennet. It 

 also so changes the nature of the curd as to cause matting. Organisms 

 of the B. hulgarkus group appear later, and reach numbers comparable 

 with those of the first group. Of less importance, probably without 

 influence upon the development of the cheese, are various cocci, liquefy- 

 ing and non-liquefying, chromogenic or showing colourless colonies. 

 Liquefying bacilli were not recovered from healthy cheese. 



Ropiness in Beer. J — From samples of ropy beer, F. E. Day and 

 J. L. Baker have isolated a number of organisms, apparently responsible 

 for this condition. These may be assigned to two groups, according 

 to their fermentative properties. The first group comprises organisms 

 which oxidize alcohol to acetic acid, and do not produce gas when grown 

 upon media containing carbohydrates. Generally speaking, these are 

 bacilli of varying size, staining feebly with Gram's method, and some- 

 times showing motility. The typical members of this group resemble 

 in many ways B. alhuminosum (Ziedler and Lindner), but show certain 

 cultural differences. The name Bacterium aceti vinosum is suggested. 

 Strains of this organism were found in every case of ropiness in English 

 beers which were investigated. The second group do not oxidize 

 alcohol, but produce gas from carbohydrates. As a rule, they are 

 medium sized rods, which stain readily by Gram's method. They re- 

 semble certain water bacteria. 



* Journ. Chem. Soc, ciii.-civ. (1913) pp. 645-50. 

 t Centralbl. Bakt., 2te Abt., xxxvi. (1913) pp. 433-8. 

 X Centralbl. Bakt., 2te Abt., xxxvi. (1913) pp. 433-8. 



