Distribution of thiamine, biotin, and niacin in the sea.

The distribution of thiamine, biotin, and niacin was investigated in surface waters collected from 20 stations in southeast Alaska, by use of bioassay methods. A marine yeast, Cryptococcus albidus, was used for thiamine, and mutants of the marine bacterium Serratia marinorubra were used for biotin and niacin. Thiamine was found in 6 (38%) of the samples in amounts ranging to 200 ng/liter; biotin was found in 8 (38%) of the samples in amounts ranging to 3.1 ng/liter. Niacin was found to be completely absent in all of the samples assayed. The significance of the presence of thiamine and biotin in the productivity of the area is discussed.