334 E. C. WASSINK 



that light promotes the uptake of inorganic phosphate and its con- 

 version into poh'phosphatos. Winternians (Sb) has shown that the 

 compounds accumulating are probalily polyphosphates; this conclu- 

 sion was reached by the comparison of properties of these compounds 

 with data in literature for polyphosphates in other organisms. A few 

 of his observations will be listed here. 



TABLE I. Decrease in TCA-soluhle Phosphate in Suspensions of Chlorella after 

 various Treatments. Summarized Results of Various Experiments (Ic). 



The phosphate compounds accumulating are not soluble in cold 

 TCA; they are easily extracted with hot IN HCl, but undergo rapid 

 hydrolysis; they are extractable by alkali with only sHght hydrolysis. 

 They move very little in a paper chromatogram (using solvents as 

 described by Hanes and Isherwood, and by Bandurski and Axelrod, 

 see 3b). They show metachromatic reaction with toluidine blue, and 

 precipitation with Ba++ at low pH; the precipitate (in one case) was 

 found to contain about 23% P. 



The accumulation of polyphosphates continues for hours; its rate 

 is increased in the absence of CO2 (Table I) . The rate becomes Hght- 

 saturated in the absence of CO2 at a much higher light intensity (viz., 

 around 1.5 X 10^ ergs/ (cm.- sec.)) than photosynthesis under similar 

 conditions (around 3 X 10' ergs/(cm.2 sec.)). However, at a much 

 lower light intensity than for photosynthesis (around 6 X 10"* ergs/ 

 (cm.^ sec.)). 



