552 THE ANAEROBIC BACTERIA 
Products of Growth. B. ivrofa'tidus is a ])r()teolytic orc^anism of 
moderate aeti\'ity. It forms a soluble proteolytic enzyme in sugar- 
free, protein-rich media, as gelatin, which will liquefy 0.5 per cent, 
carbol gelatin in the absence of oxygen. Oxygen restricts the activity 
of this enzyme to a not inconsiderable degree. 
(\)oked meat medium is first rerldened somewhat, and some gas 
forms. Soon, however, the medium becomes blackened and there is 
evidence of digestion. A fetid odor also develops. Milk is rapidly 
coagulated, and some gas may form if large volumes are examined. A 
slow, late ])eptonization of the precipitated casein takes place. Coagu- 
lated serum is also liquefied. Growth is poor in sugar-free, peptone- 
meat extract broth. 
Acid and gas are formed, according to Henry, ^ in glucose, fructose, 
mannose and galactose of the hexose series, maltose and lactose of the 
biose series, and in addition xylose, glycogen, and salicin. Saccharose 
and starch are not fermented. Glycerin fermentation appears to be 
positive for some strains and absent in others. Considerable amounts 
of ammonia are produced in media containing no utilizable carbohy- 
drate; much more in protein-rich media, as gelatin; much less in 
peptone, meat-extract media. The amino-acid content is reduced in 
sugar-free media, suggesting that the ammonia formation is associated 
with the action of the bacteria upon the amino-acids. Amino-acid 
formation is increased somewhat in media containing utilizable carbo- 
hydrates, and ammonia production is materially reduced. 
Toxin. —Soluble, poisonous products have not been detected in 
cultures of B. a^rofoetidus. 
Serological. — Specific agglutinins have been prepared by Weinberg 
and Scguin which will clump strains of the organism but not B. fallax 
or B. bifermentans, which which B. a^rofoetidus possesses some points 
of resemblance. 
Pathogenesis. — Large doses of B. serofoetidus cultures kill guinea-pigs, 
but the amount of material required to eft'ect a fatal reaction is so 
great the organism cannot be regarded as of material pathological 
significance. 
Bacteriological Diagnosis. — Mo rpholog i/.—\ rather small, non-capsu- 
lated bacillus exhibiting no capsule even in pathological tissues or 
fluids, and occurring singly or in pairs, is an important morphological 
characteristic of B. a-rofoetidus. 
Culturally, the fermentation of lactose, and the rapid liquefaction of 
gelatin are important correlated features which are not presented by 
other anaerobes of similar morphological appearance. 
The absence of pathogenic powers for guinea-pigs is also a point of 
importance in flifferentiating the organism from those with which it 
might be confused. 
1 Jour. Pathol, and Bapteriol., 1916-1917, 21, 367. 
