■Sept, a, 1933 
481 
Bacterial Leaf spot of Clovers 
After having established the fermentation relations of the clover 
organism, another series of tests was initiated to determine points of 
similarity and difference between it and Bacterium sojae . In these tests 
clover strain 1920-III and the soybean organism were grown in compara¬ 
tive cultures with the results shown in table IV. 8 
Table IV .—Comparative carbohydrate fermentations of clover strain IQ20-III and 
Bacterium sojae in bouillon containing 1 per cent sugar {initial P H 7.4) 
Age o! cultures, organism, and Ph concentration. 
Carbon compound. 
3 days—Organism. 
5 days—Organism. 
7 days—Organism. 
Clover. 
Soybean. 
Clover. 
Soybean. 
Clover. 
Soybean. 
Ph 
Ph 
P H 
P H 
Ph 
Ph 
Dextrose.. 
7. 0 
6.8 
6. 4 
6.6 
6.8 
7.2 
Saccharose. 
7. 0 
6.8 
6. 2 
6.4 
6.6 
6. 6 
Lactose. 
7-4 
7.6 
7.6 
7.8 
7.8 
8.0 
Maltose. 
7-4 
7. 6 
7-4 
7.6 
7.6 
7.8 
Glycerin. 
7-4 
7-4 
7. 6 
7.6 
7.8 
7.6 
Inulin. 
7-4 
7-4 
7.6 
7.8 
7.8 
8.0 
Galactose. 
7-4 
7-4 
7.6 
7.6 
7.6 
7.6 
Arabinose. 
7-4 
7. 2 
7.6 
6. 6 
7.8 
5-8 
Xylose. 
7-4 
6.8 
7.6 
6. 0 
7.6 
5-4 
Levulose. 
7-4 
7. 2 
7.6 
7.0 
7.6 
6.8 
Dulcitol. 
7. 6 
7-4 
7.8 
7.6 
8.0 
7.8 
Salicin. 
7-4 
7-4 
7.6 
7.6 
7.8 
8.0 
Rhamnose. 
7-4 
7-4 
7.6 
7.6 
7.8 
8.0 
Strain 1920-III is able to ferment dextrose and saccharose alone and 
is therefore identical in carbon metabolism with the other strains from 
clover. Bacterium sojae is able in addition to hydrolyze. arabinose, 
xylose, and levulose, and on this basis, together with inoculation studies 
to be reported subsequently, is regarded as specifically distinct from the 
bacterial leafspot of clover. 
It might be pointed out at this point that very little use has hitherto 
been made of the rare sugars in cultural studies of plant pathogens. 
This is due in part, no doubt, to the fact that host species with more 
than a single known bacterial disease are less common than with animals. 
Rare sugars are recognized as invaluable, however, by investigators, of 
forms pathogenic to animals in the separation of closely related species. 
Winslow, Kligler, and Rothberg (8), for example, have pointed out the 
significance of xylose and rhamnose fermentations in the colon-typhoid 
group. They found that xylose can be employed in separating the 
typhoid and paratyphoid B groups from the dysentery and paratyphoid 
A groups, while rhamnose furnishes a good basis of distinction between 
the paratyphoid (A and B) groups, and the typhoid and dysentery bacilli. 
Koser (4) has noted that Bacillus suipestifer is unable to utilize the di- 
saccharid trehalose, whereas B. paratyphosus , B. schottmulleri , and B. 
enteriditis can ferment it with the formation of both acid and gas. 
• At Washington comparative tests were made with the Virginia and the Wisconsin clover organisms in 
sugar media. Both fermented dextrose and saccharose, but the Virginia cultures produced less acid than 
the Wisconsin cultures. Neither of these clover strains fermented lactose, maltose, mannitol, galactose, 
or glycerin. 
