Feb. 1, 1925 
Decomposition of Proteins and Amino Acids 
269 
Table II.— The chemistry of decomposition of 1 per cent alanine by microorgan¬ 
isms, in the presence and absence of dextrose 
Organism used 
Dex¬ 
trose 
Age 
of 
cul¬ 
ture 
Total N in 
100 c. c. 
NH 2 —N in 
100 c. c. 
nh 3 - 
N in 
100 c. c. 
Dextrose in 
100 c. c. 
Dry growth 
pH 
Found 
De¬ 
crease 
from 
con¬ 
trol 
Found 
De¬ 
crease 
from 
con¬ 
trol 
Found 
Uti¬ 
lized 
Weight 
Nitro¬ 
gen 
con¬ 
tent 
Per 
cent 
Days 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Mg. 
Control. 
None. 
153.5 
151.5 
2.36 
7.1 
Do_ 
2 
153. 5 
151.5 
2.36 
1, 760 
6.8 
Zygorhynchus . 
None. 
12 
146.0 
7.5 
129.4? 
22.1? 
6.40 
. . 
— 
48 
3.86 
7.8 
Do.. 
2 
12 
141.3 
12.2 
120.2? 
31.3? 
1.12 
570 
1,190 
175 
9.29 
5.6 
Actinomyces... 
None. 
17 
125.1 
28.4 
64.0 
87.5 
39.17 
126 
8.97 
8.6 
Do. 
2 
17 
144.4 
9.1 
105.4 
46.1 
6.82 
i, 230 
530 
82 
7.58 
4.9 
Bact. fluorscens 
None. 
5 
70.0 
81.5 
32.82 
8.8 
Do. 
2 
5 
92.8 
58.7 
1.72 
750 
1,010 
4.8 
Control.. 
None. 
147.6 
145.3 
3.40 
7.3 
Do_ 
2 
147.6 
145.3 
3.40 
1,680 
, 
6.8 
Trichoderma... 
None. 
6 
135.2 
12.4 
107.5 
37.8 
21.98 
80 
6. 97 
8.3 
Do. 
2 
6 
124.4 
23.2 
107. 6 
37.7 
7.64 
400 
1,280 
562 
24.32 
5.2 
( 1 ) R.CH(NH 2 ).COOH + 2 H = R. 
CH 2 .COOH + NH 3 
R.CH 2 .COOH + 30=R.COOH 
+co 2 +h 2 o 
R.COOH = R H + C0 2 
The first step in the reaction is the 
splitting off of the ammonia (reductive 
deaminization), followed by the gradual 
decomposition of the nitrogen-free 
molecule, resulting in the liberation of 
energy and C0 2 . The reaction may 
also take place as follows: 
( 2 ) R.CH(NH 2 ).COOH = R.CH 2 . 
nh 2 +co 2 
(3) R.CH(NH 2 ).C00H + H 2 0 = R. 
CHOH.COOH + NH3 
In reaction (2) we have the formation 
of an amine, as an intermediary step, 
.and liberation of energy and C0 2 . In 
the third reaction we again have 
deaminization, by means of hydrol¬ 
ysis, with the formation of an oxy-acid. 
Nawiasky found that B. proteus is 
capable of attacking glycocoll to a 
limited extent, changing a part of it to 
acetic acid. 
CH 2 (NH 2 ) .COOH + 2 H = CH 3 COOH 
+ NH 3 
A part of the acetic acid is probably 
utilized as a source of energy, in the 
absence of an available carbohydrate. 
DECOMPOSITION OF ALANINE 
trose (Table II); out of this, 21.98 mg. 
has been changed to ammonia and 6.97 
mg. has been reassimilated. The organ¬ 
ism synthesized 80 mg. of mycelium, 
which contains about 36 mg. of carbon; 
the amino acid decomposed contained 
37.8X2.57 = 97.15 mg. of carbon; in 
other words, the organism reassimilated 
about 37 per cent of the carbon that it 
has decomposed. About the same 
amount of alanine has been decom¬ 
posed by the Trichoderma also in the 
presence of dextrose, but a much 
smaller amount of the nitrogen is found 
as ammonia and a much larger quan¬ 
tity of it was reassimilated. The pro¬ 
cess of carbon utilization in the pres¬ 
ence of dextrose is 
562X45 per cent 
l,280X40^er cent+37.7 X 2.57 
per cent. The organism is somewhat 
more efficient in synthesizing its proto¬ 
plasm, in the presence of an available 
carbohydrate, requires less energy, and 
assimilates less nitrogen pqj* unit of pro¬ 
toplasm synthesized. 
The Actinomyces synthesized 126 mg. 
mycelium from an amount of alanine 
decomposed which is equivalent to 87.5 
mg. of nitrogen; the efficiency of this 
organism is 
126X45 per cent 
87.5X2.57 
25.1 per 
The chemical formula for alanine 
is CH 3 .CH.(NH 2 ) .COOH; it contains 
15.73 per cent nitrogen and 40.4 per 
cent carbon, or 2.57 times as much 
carbon as nitrogen. The Trichoderma 
decomposed alanine equivalent to 37.8 
mg. of nitrogen, in the absence of dex¬ 
cent. In the presence of dextrose, 
the Actinomyces decomposed alanine, 
equivalent to 46.1 mg. of nitrogen, and 
530 mg. of dextrose, but synthesized only 
82 mg. of mycelium, showing a lower 
efficiency. This tends again to bring 
out that the Actinomyces may prefer 
13951—251-6 
