Chemical quality and production of agars extracted from Gracilaria tikvahiae grown indifferent nitrogen enrichment conditions

Increasing concentrations of nitrogen fertilizer led to increased growth and internal nitrogen content of Gracilaria
tikvahiae and decreased yields of agar. The thallus nitrogen content was highly correlated with percent protein and
protein : carbohydrate ratios, and percent agar was highly correlated with percent carbohydrate. Agars extracted from
thalli grown under nitrogen enriched conditions had higher melting temperatures and greater gel strengths than did
agars extracted from less enriched thalli. The data suggest that the increased gel strengths found in these experiments
may be due to the greater molecular size of the agar polymers, as indicated by the increased melting temperatures
associated with greater gel strengths.