No abstract

This work evaluated the cultivation of the macroalgae Ulva ohnoi on the performance of algal biomass and changes in its proximate and biochemical composition after cultivation in a biofloc system. U. ohnoi was cultivated in three experimental units with aeration, heating, initial density of 6 g L-1 for 28 days. The water used for cultivation was collected from a biofloc matrix tank and exchanged 90% once a day throughout the experiment. Temperature, salinity and illuminance were measured twice a day. To evaluate the growth of the macroalgae, weekly weighing was performed, and the daily growth rate was calculated. The density of each experimental unit was weekly adjusted to the initial density (6 g L-1), and the remain was saved for the composition analyses. Results showed an average plant growth of 1.15% day-1, totaling 49.5 g of weekly biomass increase. A significant difference was observed when comparing the initial 2.64±0.3% and final 4.62±0.2% ulvan concentration, and an increase of 30.2% in protein concentration at the end of the cultivation. No statistical differences were found regarding the concentration of phenolic compounds and chlorophylls (a and b) during the weeks. An increase in flavonoid concentration was observed on days 7 and 14 (0.41±0.04; and 0.41±0.07 µg g-1 of dry weight), as well as a decrease in carotenoid concentration of approximately 41.3 %. In conclusion, an increase in protein and ulvan concentrations were observed after the macroalgae U. ohnoi was cultivated in the biofloc system.

No abstract

No abstract