Extraction and purification of a phycocolloid from Chaetomorpha aerea

Phycocolloids are gelling polysaccharides extracted from algae that have found applications as microbiological culture media, food thickener, and cosmetic rheological modifiers. The extensive use of algae species that have not been yet domesticated has led to overexploitation or supply shortages. Thus, extending the library of phycocolloids would permit to support the industrial changes towards renewable polymer feedstocks but if the source of algae is limited to wild algae species, this might raise issue on the scalability and hinder the creation of a reliable supply chain. In this study, we have identified a new phycocolloid extracted from Chaetomorpha aerea, a green seaweed that can be cultivated in open ponds. Through elucidation of its chemical structure, we propose a gelation mechanism for an extracted sulfated polysaccharide fraction that form stable, transparent hydrogels that can be used for microbiological culture.