Investigation of alginate and two plant hormones from brown macroalga Sargassum muticum (Phaeophyta)

Brown seaweeds contain compounds such as alginate and phytohormones that have many uses in industries. This research was conducted to determine biomass and extract two phytohormones and alginate from Sargassum muticum. Sampling was done from January 2014 to November 2015 in Bushehr port, one month apart. Biomass and environmental parameters were measured in the selected transect and the algae were sampled. After extraction, hormones were separated by HPLC and identified by standard injection. The highest biomass of alga was in January (679±2.12g/m2) and the lowest was in September (20.67±0.76 g/m2). Alginate reached the lowest leve (40.67±1.03%) in November and the highest level (54.67±2.25%) in January, which had a positive correlation with biomass. The highest amount of gibberellin (5.86±1.11%) was in July, which had a positive correlation with temperature. Zeatin was obtained only in May (0.18±0.07%). According to the results, in order to extract alginate, gibberellin and zeatin from this alga, it should be done in January, July and May, respectively. Considering the high price and the necessity of using these materials in industries, agriculture and as algae liquid fertilizer, this research is a starting point for extracting substances and hormones from this alga.