The Cultivation of Chondrus crispus. Effect of pH on Growth and Production of Carrageenan

Abstract

A clone, T4 of C. crispus was grown in flowing seawater in a greenhouse under conditions of constant pH. Without pH control the diurnal fluctuations in pH ranged between 7.9 to 9.6. Maintaining the pH constant by the controlled addition of HCl, H2SO4 or CO2 resulted in improved yields. CO2 was superior to the inorganic acids or daily additions of NaHCO3. Maximal yields with CO2 as the controlling agent were obtained at pH 7.0; with HCl or H2SO4, maximal yields were obtained at 7.5 to 8.0. At pH 9.0 and 9.5 the plants bleached and fragmented. The yield of plants and carrageenan per week per g of inoculum, was greatest at the lowest density of plants.