Orthophosphate was determined by the method of Berenblum and 

 Chain'^^ modified by Yanagita^^) using the supernatant obtained by Pro- 

 cedure I, 



I 



li 



METABOLISM OF INORGANIC POLYPHOSPHATES IN GROWING 



CHLORELLA CELLS 



Shigetoh Miyachi 



In our laboratory we have been studying on the overall changes in 

 phosphorus compounds in plant cells occuring during photosynthesis. It 

 was found that Chlorella ellipsoidea cells contain large quantities of inor- 

 ganic polyphosphates. These have been separated into four fractions: 

 poly-P"A" (acid-soluble), poly-P"B" (acid-insoluble but soluble in cold 

 alkali at pH 8-10), poly-P"C" (insoluble either in cold a'cid or in cold 

 alkali at pH 8-10, but extractable with 2NK0H at 37° and co-precipitable 

 with potassium perchlorate which is formed upon neutralization of the 

 KOH -extract with perchloric acid (PCA)) and poly-P"D" (extractable with 

 2NK0H together with poly-P"C", but different from the latter, does not •;' 



CO -precipitate with potassium perchlorate which is formed upon neutrali- | 

 zation of the extract with PCA). In order to understand the role of inor- 

 ganic polyphosphates in phosphate transfer among the cell constituents, 

 observations were made on the changes of P -distribution occurring in 

 Chlorella grown under photos ynthetic conditions or under continued dark- 

 ness in the presence or absence of an exogenous P-source. 



METHODS 



The analysis of phosphorus compounds within the algal cells were 

 determined according to published methods^ ^ with modifications (cf. 2, 

 3) as follow. The cell material was treated successively with: (I) cold 

 8% TCA, (II) cold ethanol and hot ethanol -ether, and (III) cold KOH solu- 

 tion of pH 9. The residue thus obtained was (IV) incubated with 2NK0H 

 at 37° for 16-20 hours, and (V) the supernatant was neutralized with PCA; 

 then (VI) to the supernatant was added PCA to a final concentration of 10%, 

 and (VII) the precipitate formed was suspended in 5% PCA and heated for 

 20 minutes at 100°. 



688 



