BACTERIAL DESTRUCTION OF COPEPODS 223 



SESSIONAL PAPER No. 38a 

 Fermentation of Carbohydrates : — 



Glucose. Lactose. Saccharose. Eaffinose. Maltose. 



■H- zt - ++ ++ 



Mannite. Dulcite. Adonit. Salicin. Dextrine. Iiiulin. 



++ ++ ++ 



Xylose. Glycerine. 

 -H- ++ (slowly). 



+ = acid. 

 ++ = acid and gas. 



Note. — The fermentation of lactose to acid is faint, and in two days reduction 

 is noted. 



The classification of this culture must be purely tentative. It will be seen that 

 while saccharose, maltose, mannite, salicin and dextrin are fermented to acid and 

 gas, the organism fails to ferment lactose to gas and only faintly to acid. This has 

 persistently been the case through several months; on one occasion, however, a small 

 bubble of gas— 1 mm. diameter — appeared in a Durham tube. This I have been 

 unable to obtain since, confirming in triplicate. MacConkey states: "It has been 

 my experience that where an organism produces acid and gas in one medium and 

 apparently only acid in another, under proper subcultivation the organism will pro- 

 duce gas in the second medium."" Harrison in this laboratory has frequently cited 

 to me verbally his own experience in this matter, which bears out the statement of 

 MacConkey. While the organism is definitely motile it difFers from B. cloacae of 

 Jordan'^ in that it fails after three months to liquefy gelatine, fails to ferment lac- 

 tose to gas, and fails to coagulate milk after several weeks. Rogers Clarke and 

 Evans^° found that the group of the types they isolated from grains — Group B — 

 fermented to acid and gas glucose, saccharose, mannite, glycerine and adonit, but 

 like my culture failed to ferment lactose; on the other hand this group liquefied 

 gelatine.^" These workers consider that such group has at best only a slight connec- 

 tion with the colon-cero genes group. Taking the classification adopted by the 

 American Public Health Association ^ the culture would be ruled out of 

 the colon-cero genes group at once on account of its failure to produce gas trom 

 lactose; further, milk is not coagulated. Certain of the biochemical reactions 

 would tend to suggest the Gaertner group. According to Besson^'- the organisms 

 of this group are negative to lactose, saccharose, salicin, rafiinose and inulin; while 

 those carbohydrates to which the group is positive include dulcite. This organism, 

 it will be noted, is negative to dulcite, lactose and inulin but positive to saccharose 

 and salicin. Jordan^- in a study of 74 strains of the Gaertner group cites that the 

 reaction to dulcite and xylose is variable, but includes dextrine among the fermentable 

 substances not attacked; thus establishing at once a similarity and a variation 

 respectively as compared with the organism here described. In the same paper 

 Jordan describes strains where reaction to litmus milk cannot be differentiated from 

 the control. Savage ^^ in a classification of the Gaertner group divides such into two 

 bub-groups : — ■ 



a. True- Gaertner bacilli; 

 h. Para-Gaertner bacilli; 



to which he had previously drawn attention in reports to the Local Government 

 Board, 1906-7-8. Citing from Savage: "The bacilli of the para-Gaertner sub-group 

 are a number of organisms, for the most part unnamed, which appear to be not very 

 uncommon in the healthy animal and human intestine, and which are of chief 

 interest from their close resemblance to true-Gaertner bacilli. . . . They can only 

 be culturally differentiated from the true-Gaertner organisms by an extended series 

 of fermentation tests while they fail to be agglutinited by immunizing animals with 



