Sulfur Metabolism in Algae. I. Synthesis of Metabolically Inert Chloroform‐Soluble Sulfate Esters by Two Chrysomonads and Chlorella pyrenoidosa*

SYNOPSIS. Ochromonas danica and O. malhamensis were grown in the presence of Na2S35O4. Four chloroform‐soluble S35‐compounds were separated from them, one of which was also found in the chloroform extract of Chlorella pyrenoidosa. All four S35‐compounds were hydrolyzed by acid to yield S35‐sulfate. Two of the S35‐compounds were fed to O. danica and incorporated into the organism without reduction of the S35‐sulfate. Evidence is presented suggesting a structural relationship between these chloroform‐soluble S35‐compounds.