GROWTH AND THE CONTENT OF LAURINTEROL AND DEBROMOLAURINTEROL IN LAURENCIA-OKAMURAE (CERAMIALES, RHODOPHYTA)

The growth of Laurencia okamurae and the content of laurinterol and de bromolaurinterol were influenced by various factors. Temperature influ enced growth rate with a maximum at 25 degrees C, regardless of daylen gth. Maturity depended on temperature rather than daylength; the plant s grew without maturing at 15 degrees C, while the plants matured with in two weeks at 25 degrees C. The plants were able to grow at saliniti es of 14-50 parts per thousand with maximum growth at 26 parts per tho usand. The growth rate reduced with decreasing concentration of nitrat e below 1.2 x 10(-3) M, and of total phosphate below 7.5 x 10(-8) M. B romide concentration had no effect on growth, and the plants grew with out bromide. Variation in temperature between 15-25 degrees C and dayl ength produced no obvious change in laurinterol and debromolaurinterol contents. On the other hand, an increase in salinity led to an increa se for both. The plants cultured in a completely artificial medium, mo dified ASP(12)NTA, showed a marked drop in their content of these meta bolites. An increase in concentrations of nitrate, total phosphate or bromide did not restore the content.