The variation of the growth rate in Gracilariopsis tenuifrons, from the Araya
Peninsula (Sucre state, Venezuela), subjected to different concentrations of NH4+
(2, 4, and 8 µmol. L-1), as well as the strength, point melting and gel point of the gel. The experimental work was carried out
under light and photoperiod natural conditions. The highest growth rate (4%) was determined, which
occurred during the first week, and significant differences were obtained for the growth rate in relation
to the sampling weeks. While the ammonium concentrations in relation to the parameters considered in
this work did not show significant interactions. Agar extraction was carried out where the agar yield, gel
strength, melting point and gel point were analyzed in relation to the concentrations. The values obtained
were 24.34 and 27.39%, 257.03 and 319.87 g/cm2, 81.67 and 86.67°C, 35 and 37°C, respectively; and
in relation to the weeks of sampling the observed results were 24.0 and 26.45%, 231.46 and 374.12 g/cm2
, 82.0 and 84.50 ºC, 35.33 and 37.16 ºC for the same parameters, respectively. According to these
results, it could be established as appropriate values for the cultivation areas of G. tenuifrons, those whose
ammonium range is within those used in this study, since they would not affect the algae growth rate or the
rheological characteristics of the agar obtained
