BIOASSAY OF ORGANIC MICRONUTRIENTS IN THE SEA

Abstract

A bioassay technique for organic micronutrients in sea water is described. The use of biochemically deficient mutant strains of a marine bacterium for this purpose is a novel approach, and the preliminary data indicate that the assays are valid. The results of the application of the bioassay indicate that sea-water does, indeed, contain organic micronutrients. Of the 10 substances assayed for, biotin, uracil, and isoleucine appeared most frequently. One occurrence of purine and 2 isolated occurrences of glycine were noted. More recently, tryptophan and threonine have each appeared in one sample. A series of weekly samples from a shore station have given much valuable information concerning the validity and reproducibility of the technique. It is expected that extended application of the bioassay technique will elucidate some unexplained discontinuities in the distribution of marine organisms and may be of value in the description and indentification of water masses and in tracing their movements.