Extraction of novel sulfated polysaccharides from Aphanothece sacrum (Sur.) Okada, and its spectroscopic characterization

Abstract

We extracted polysaccharides (PS) from Aphanothece sacrum using a hot alkaline solution which degraded other biopolymers such as proteins and nucleotides. The spectroscopy and elemental analyses indicated the PS contain carboxyls and sulfate groups. The degree of sulfation was estimated as about 10 mol %. 1H NMR studies demonstrated that the PS of A. sacrum had a dimethylated fucose unit. The combination of sulfate group and fucose in the prokaryotic PS was first evidenced by the direct spectroscopic studies. The PS showed efficient gelation behavior, binding to metal ions abundant in soil, and the swelling volume of the gel was approximately 250 times the dry volume. These results imply that PS of A. sacrum, which has been mass cultivated in Japan for a long time, may have potential as an environmentally benign water absorbent.

Development of Functional Bionanocomposites Using Cyanobacterial Polysaccharides

“…They can exhibit high structural and functional properties together with the biocompatible and biodegradable characteristics associated with biopolymers . In order to develop a series of bionanocomposites of cyanobacterial polysaccharides, we have used sacran, which is a recently‐developed supergiant polysaccharide extracted from the edible cyanobacteria Aphanothece sacrum which is mass‐cultivated in natural rivers . As described in next section, sacran had an average M w of 2.35×10 7 g/mol determined by light scattering (MALLS; detection angle from 15° to 40°) as absolute value, and we believe that this value of molecular weight can be regarded as a world record of extracted molecules.…”

“…Aphanothece sacrum (A. sacrum) is mass‐cultured in fresh water in Japan, and its extracellular matrix includes metal ions that create a jelly‐like material (gel) which protects the cells, and may be useful as a scaffold for cell proliferation. Sacran was extracted from A. sacrum biomaterials by the following procedure . The A. sacrum samples were freeze‐thawed in order to break the cell membranes and then washed with pure water to clear water‐soluble materials such as aqueous pigments (phycobiliproteins).…”

Physiological properties and genetic analysis related to exopolysaccharide (EPS) production in the fresh-water unicellular cyanobacterium <i>Aphanothece sacrum</i> (Suizenji Nori)

“…Alternatively, a unique uronic acid(s) such as nosturonic acid (Helm et al, 2000) might be contained in the sugar chains. The chemical properties of EPS were almost the same as that of A. sacrum cultured in a traditional aquafarm (Okajima-Kaneko et al, 2007).…”

“…Cell sheets of A. sacrum are preserved as salted or dried forms, and served in traditional Japanese cuisine. Okajima-Kaneko et al (2007) determined the partial molecular structure of the EPS using A. sacrum that was cultured in the open-air aquafarm. The EPS of A. sacrum has an extremely high molecular weight of over 1.6 ¥ 10 4 kDa, and has carboxylate groups in 17 mol% and sulfate groups in about 12 mol% of the sugar residues (Okajima et al, 2007).…”

Evaluation of an Edible Blue-Green Alga,Aphanothece sacrum, for Its Inhibitory Effect on Replication of Herpes Simplex Virus Type 2 and Influenza Virus Type A

“…18) The polysaccharide, named as sacrun, was reported to contain sulfated muramic acid as a chain constituent, and to show good absorption capacity for saline. 19) However, little information about biological effects of sacrun is available.…”