Sept. 22 ,1923 
Bacterial Leaf spot of Clovers 
479 
but all cultures became progressively more alkaline in the other com¬ 
pounds. 
Bouillon with sugars. —Liquid media were used ta follow the pro¬ 
gressive changes in hydrion concentration produced during the fermenta¬ 
tion of the several carbon compounds. Plain bouillon consisting of 1 per 
cent Difco peptone, 0.3 per cent Liebig's beef extract, and 0.5 per cent 
sodium chlorid served as a stock solution. The sugars prepared sepa¬ 
rately were added to this bouillon to make a concentration of 1 per cent. 
During the course of this investigation the organism causing bacterial 
leafspot of clover has been used in parallel cultural studies with Bacterium 
glycineum and Bad. sojae from soybean and found to possess many 
characters in common with them. These studies as regards the soybean 
organisms have been reported in other papers ( 2 , 6 , 10). In view of the 
fact that it was found to be impossible to separate the clover organism 
from Bad. sojae on the basis of its fermentative ability on media con¬ 
taining the common sugars, it was believed that the “rare" sugars could 
be employed with success in distinguishing them. Accordingly, in addi¬ 
tion to preparing bouillon containing dextrose, saccharose, lactose, 
maltose, or glycerin in concentrations of 1 per cent, a series of tubes were 
prepared with bouillon containing 1 per cent of either of the following: The 
pentoses, xylose and arabinose; the methylpentose, rhamnose; the 
hexoses, levulose and galactose; the alcohols, mannitol and dulcitol; the 
polysaccharids, inulin and dextrin; and the glucoside, salicin. Three 
strains of the pathogen, one from red, another from white, and the third 
from alsike clover, were used in one of these series. The tubes containing 
the cultures to be tested were compared colorimetrically with standard 
buffer solutions. Changes in reaction resultant on fermentation were fol¬ 
lowed by readings at 24-hour intervals. A considerable number of 
cultures of each strain with each sugar was employed so that several 
different tubes could be used in each consecutive reading. The results 
of these fermentation tests are assembled in Tables I, II, and III. 
Table I .—Fermentation of various carbon compounds in plain bouillon by the organism 
from alsike clover (initial P H 7.2) 
Carbon compound. 
Age of culture and Ph concentration. 
a days. 
3 days. 
4 days. 
5 days. 
6 days. 
7 days. 
Ph 
Ph 
Ph 
Ph 
Ph 
Ph 
Dextrose. 
7. 2 
7. 0 
6.6 
6. 2 
6.4 
6.6 
Saccharose. 
7. 2 
7 . 2 
7. 0 
6.6 
6. 2 
6.6 
Lactose. 
7.2 
7.2 
7. 2 
7-4 
7-4 
7.6 
Maltose. 
7. 2 
7.2 
7.2 
7. 2 
7.2 
7-4 
Glycerin. 
7.2 
7.2 
7.2 
7-4 
7-4 
7.6 
Inulin. 
7. 2 
7*4 
7. 6 
7. 6 
8.0 
8.0 
Dextrin. 
7. 2 
7. 2 
7.2 
7-4 
7-4 
7.6 
Arabinose. 
7 . 2 
7.2 
7.2 
7-4 
7*4 
7.6 
Xylose. 
7.2 
7.2 
7.2 
7-4 
7-4 
7, 6 
Levulose. 
7 . 2 
7. 2 
7. 2 
7*4 
7-4 
7.6 
Dulcitol. 
7. 2 
7-4 
7-4 
7. 6 
7.8 
7.8 
Mannitol. 
7.2 
7-4 
7-4 
7-4 
7. 6 
7*6 
Salicin..... 
7 * 2 
7. 2 
7. 2 
7. 2 
7 » 4 
7.6 
Galactose. 
7 . 2 
7. 2 
7. 2 
7. 2 
7. 2 
7'4 
Rhamnose. 
7. 2 
7.2 
7.2 
7-4 
7-4 
7.6 
