NUTRITIONAL STUDIES OF THE EDIBLE SEAWEED PORPHYRA TENERA I. THE INFLUENCE OF DIFFERENT B12 ANALOGUES, PLANT HORMONES, PURINES AND PYRIMIDINES ON THE GROWTH OF CONCHOCELIS

Abstract

The red alga Porphyra tenera has been obtained in axenic culture by the “dip and drag” technique in an agarized medium containing antibiotics. In the axenic culture, the Conchocelis of P. tenera needs vitamin B₁₂ for growth. The addition of other vitamins does not increase growth further. The pattern of specificity is similar to that of Escherichia coli 113-3. Factor B, pseudovitamin B₁₂ and Factor Z₂ support as much growth as vitamin B₁₂, while 2-methylmercaptoadenine and 5-methyl benzimidazole cobalamine increase the growth more than B₁₂. All the analogues containing benzimidazole can replace B₁₂. Kinetin, adenine, indoleacetic acid and especially gibberellic acid increase growth. Three purines, (xanthine, hypoxanthine and guanine) and three pyrimidines (uracil, methylcytosine and thymine) also promote growth in the presence of vitamine B₁₂.