COMPOSITION OF MICROBIAL AMINO ACID POOLS 103 
tion. Oxygen uptake declined as the pool was depleted and there appeared to be no 
utilization of carbohydrate, protein or lipid stores. This, of course, is not a typical 
finding since, for example, yeast utilizes carbohydrate as a reservoir substrate for 
endogenous respiration. GROS AND Gros have suggested that a complete amino 
acid pool is necessary for RNA synthesis. An effort was made to exclude the alternate 
interpretation that protein synthesis must occur simultaneously by measuring RNA 
synthesis in the presence of chloramphenicol. The validity of the conclusion, therefore, 
rests on the completeness of the inhibition in protein synthesis. 
There is a sizeable literature recording efforts to correlate pool composition and 
other cell processes such as antibiotic synthesis! 122; 147, pathogenicity*® 12°, mating 
type*8, etc. With few exceptions, clear-cut correlations have not been encountered. 
Such negative findings possibly are not unexpected, but need not necessarily be taken 
as an indication that pool studies have little value in this regard. It seems likely in 
fact that the opposite will be found to be true if, in addition to its composition, the 
flow of substances through the pool is examined using tracers. Except in the investi- 
gations relating to protein synthesis this approach has not been employed extensively. 
One of the most prevalent applications of microbial pool studies has been in the 
area of taxonomy. Among the fungi the findings appear uniformly to inspire pessi- 
mism, 2.e., neither separation of species nor genera seems possible on the basis of 
TABLE XII 
A SUMMARY OF THE DISTINGUISHING CHARACTERISTICS ON CHROMATOGRAMS 
OF 63 STRAINS OF L. casei AND L. plantarum 
(Adapted from CHEESEMAN®®. ) 

Nos. of strains of 
Property L. casei L. plantarum 

Typical Atypical 
Typical Atypical 


Origin 
— in caset 29 oO 30 4 
+ in plantarum 
a-Aminobutyric acid 
— in caset 29 oO 30 4 
+ in plantarum 
Proline 
— in case 27 
+ in plantarum 
Asparagine 
— or faint in casei 20 3 33 I 
strong + in plantarum 
Ratio glycine/threonine 
> 0.8 in casei 20* 8 24* 5 
< 0.8 in plantavum 
Ratio 50, 70/alanine 
> 1.0 in casei 2 I 27 
< 1.0 in plantarum 
N 
34 oS 
* 
NN 

* Excluding five strains of L. plantarum and one strain of L. casei which were not examined 
quantitatively. 
References p. 105/108 
