Modification of Protein Synthesis by Vitamin B₁₂ in the Marine Algal Flagellate Neochloris pseudoalveolaris*

SYNOPSIS. A strain of the marine algal flagellate Neochloris pseudoalgeolaris required only an inorganic medium for growth; however, in media containing vitamin B 12 it became greener, protein synthesis was modified, and the levels of DNA and RNA increased. By isotope tracer technics, transmethylation of the methyl group of methionine was found to play a role in modulation of protein synthesis governed by the vitamin. These results indicate that vitamin B 12 stimulates synthesis of chloroplasts in this algal strain.