A Further Note on the Culture of Spirogyra 



Paul F. Brandwein 



Last year the writer ( 1 ) published some preliminary observations 

 on the cultivation of a species of Spirogyra, which, however, remains 

 unidentified due to its failure to produce zygospores. Essentially, 

 the method involved introducing Spirogyra into a Daphnia culture 

 in egg yolk-tap water medium. Although the method is crude the 

 growth of the alga in this micro-pond, as it were, is remarkable. 



Since then an inorganic solution has been developed to replace 

 the tap water which may vary in different localities. Furthermore, 

 preliminary work indicates that the Daphnia and egg yolk may also 

 be dispensed with. This information is presented in the present 

 paper with a view to aiding those who may be working with the 

 alga. 



The constituents of the inorganic solution were suggested by 

 an analysis of New York City tap water ;■ the concentration of the 

 salts was increased, however, after due experimentation. Since 

 previous work indicated that Spirogyra requires some organic 

 material to stimulate growth, a search was made for a suitable 

 substance. After countless failures it was found that Bacto-trypto- 

 phane powder (a Difco product) was the best. The results at 

 present seem to show that the substances required are in the nature 

 of proteins, perhaps simple amino acids. Arginine, which Czurda 

 (2) used, and glycine do not appear to be as suitable as the Bacto- 

 tryptophane digest. The growth of the alga is not as rapid, how- 

 ever, as in the Daphnia culture. The ingredients of the medium 

 follow : 



NaCl 0.008 gm. 



MgS04 0.012 gm. 



KNO3 0.005 gm. 



FeCls 0.0002 (trace) 



CaS04 0.03 gm. 



Bacto-tryptophane powder (Difco) 50.0-70.0 milligm. 



Dist. HoO 1000.0 cc. 



The Spirogyra cultures are best maintained at temperatures 

 between 20 and 22° C. in light of medium intensity. The writer 

 will be glad to supply the alga upon receipt of a suitable container. 



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