title: Organic aggregates formed by benthopleustophyte brown alga Acinetospora crinita (Acinetosporaceae, Ectocarpales).
abstract: This work presents the elemental, polysaccharide, and fatty acid compositions of benthic aggregates formed by the filamentous brown alga Acinetospora crinita, which are widely spread on the rocky bottoms of the Mediterranean Sea. The aggregates can be characterized as mineralized centers in which regeneration of nutrients and recycling of dissolved organic matter actively occur and favor the development of an abundant phytoplankton community. Analyses of the stable isotopes of C and N display their marine origin and could provide evidence of the processes that occur inside/outside of the aggregates. The monosaccharide compositions of Adriatic and Tyrrhenian mucilages produced by brown alga A. crinita were quite similar. In particular, the Adriatic sample compositions resembled the average composition of the Tyrrhenian high molecular weight exopolymers, and the observed differences could be ascribed to different degradation stages. The fatty acid patterns found for the aggregates were similar to those observed in the isolated A. crinita algae with variable contributions from embedded diatom species. The bacterial contribution to the fatty acid pool was quite low, most likely due to the known poor conditions for their heterotrophic growth.
authors.affiliation: National Institute of Oceanography and Experimental Geophysics (OGS), Trieste, 34151, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Giani
authors.affiliation: Department of Biology, University of Firenze, Firenze, 50121, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sartoni
authors.affiliation: Department of Biology, University of Firenze, Firenze, 50121, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Nuccio
authors.affiliation: Istituto Superiore per la Protezione e la Ricerca Ambientale, Chioggia, 30015, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berto
authors.affiliation: Agenzia Regionale per la Protezione dell'Ambiente dell'Emilia Romagna, Cesenatico, 47042, Italy.
authors.forename: Carla Rita
authors.initials: CR
authors.lastname: Ferrari
authors.affiliation: Institut "Ruđer Bošković", Center for Marine Research, Rovinj, 52210, Croatia.
authors.forename: Mirjana
authors.initials: M
authors.lastname: Najdek
authors.affiliation: Department of Life Sciences, University of Trieste, Trieste, 34127, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Sist
authors.affiliation: Department of Life Sciences, University of Trieste, Trieste, 34127, Italy.
authors.forename: Ranieri
authors.initials: R
authors.lastname: Urbani
mesh_terms: D001704:Biopolymers / Q000032:analysis*; D017523:Croatia; D005227:Fatty Acids / Q000032:analysis*; D000459:Phaeophyceae / Q000737:chemistry* / Q000254:growth & development; D011134:Polysaccharides / Q000032:analysis*
chemical_list: D001704:Biopolymers; D005227:Fatty Acids; D011134:Polysaccharides
keywords: Acinetospora crinita; aggregates; brown algae; filamentous algae; lipids; polysaccharides