956 
J ournal of Agricultural Research 
Voh XXX, No. 10 
in the same manner. While the cab¬ 
bage was being placed in the vats, 
per cent of common salt was added by 
the regular sal ter of the factory. 
The contents of one vat were inocu¬ 
lated with about 2 liters of a three-day- 
old culture of lactic acid bacteria in a 
1 per cent glucose-yeast-water medium. 
This culture was diluted with an equal 
volume of water and applied to the 
cabbage with a small water sprinkler 
while the cabbage was being placed in 
the vat. An equal amount of water 
was added to the control which re¬ 
ceived no inoculation. 
When filled, the vats were shipped 
to the laboratory and stored in a room 
where the temperature was approxi¬ 
mately 20° C. Analyses were begun 
about 24 hours after the cabbage was 
packed into the vats. Whenever a 
layer of kraut was removed for an 
analysis the first 6 inches was discarded 
before the sample for analysis was 
taken. 
The total number of bacteria present 
at different stages of fermentation of 
the kraut were determined by the 
dilution method, the plate method, 
and the direct count or Breed method. 5 
The organisms present were classified 
in groups according to their ability 
to ferment various sugars, mannitol, 
and litmus milk. Yeast water con¬ 
taining 1 per cent of these compounds 
was used as a culture medium. 
The chemical work consisted of de¬ 
termining the amounts of volatile and 
nonvolatile acid and alcohol and the 
total amount of sugar in the brine. 
The methods used have been described 
in previous publications. 6 
DETERMINATION OF THE NUMBER OF 
BACTERIA BY THE PLATE METHOD 
To determine the number of bac¬ 
teria present, glucose-yeast-water agar 
plates were poured from dilutions of 
kraut brine made in the usual manner 
(Table I). 
Observations made on the plates at 
the time of counting showed marked 
differences in appearance at the various 
intervals of plating. There was also a 
noticeable difference in the flora on the 
plates made from uninoculated kraut. 
This was most noticeable during the 
first days of the fermentation. The 
plates made from the brine 1 day 
old showed a large number of molds of 
various types and many different forms 
of bacteria. Some of these formed 
large, slimy, raised colonies; some, thin 
spreading colonies; and others, chromo- 
genic colonies ranging in color from 
gray or brown to orange and red. 
The chromogens and molds were pres¬ 
ent on the plates from both the in¬ 
oculated and uninoculated kraut but 
did not appear on plates from dilutions 
greater than 10,000. 
Table I .—Number of bacteria in young 
sauerkraut as obtained by the plate 
method 
Age 
I 
Number of bacteria in 
1 c. c. of brine 
Uninoculated 
Inoculated 
Days 
1 .... 
Thousands 1 
200 
5,000 to 5,500 
6,000 to 6,400 
39,000 to 40,000 
Thousands 1 
170 to 700 
3,900 to 4,000 
8,000 to 8,200 
50,000 to 55,000 
3.. 
5.... 
7.. 
1 Thousands—i. e., 000 omitted. 
By the third day the flora had changed 
and practically onlyjtwo types of bacter¬ 
ial colonies were present—one a small 
lens-shaped colony which grew beneath 
the surface, and the other a surface 
colony which had a solid center and a 
hazy border. The uninoculated kraut 
showed two or three spreading colonies 
per plate at a dilution of 1,000, but the 
plates made from the inoculated kraut 
showed no molds or spreading colonies. 
The molds, spreading colonies, and 
chromogens in the natural fermentation 
persisted for only four or five days. 
By the fifth day only two types of 
colonies were present on both control 
and inoculated plates—the small colony 
beneath the surface and the large 
colony on the surface. The small 
colonies were more abundant than the 
large colonies, and this ratio was more 
marked in the inoculated than in the 
uninoculated kraut. 
THE NUMBER OF BACTERIA AS DE¬ 
TERMINED BY DIRECT COUNT OR 
BREED PLATE METHOD 
Each time the vats were opened a 
sample of brine was removed with a 
sterile pipette and used for making 
fi American Public Health Association and Association of Official Agricultural Chemists’ 
STANDARD METHODS OF MILK ANALYSIS. BACTERIOLOGICAL AND CHEMICAL. Ed. 4, 40 p., illUS. New 
York City. 1923. 
6 Fred, E. B., Peterson, W. H., and Davenport, A. acid fermentation of xylose. Jour. 
Biol. Chem. 39: 347-384, illus. 1919. 
-,-, and Anderson, J. A. the characteristics of certain pentose-destroying bacteria, 
especially as concerns their action on arabinose and xylose. Jour. Biol. Chem. 48: 385-412, illus. 
1921. 
