The characterization and comparison of exopolysaccharides from two benthic diatoms with different biofilm formation abilities

Abstract

Exopolysaccharide (EPS) of two benthic diatoms, Amphora sp. and Stauroneis sp., with different biofilm formation abilities were investigated. The ratio of suspension-cells/biofilm-cells was employed to indicate the diatom biofilm formation abilities. The soluble EPS from the supernatant of whole culture, tightly bound EPS from floating cells, loosely and tightly bound EPS from biofilm cells were fractionated as SL-EPS, F-TB-EPS, BF-LB-EPS and BF-TB-EPS, respectively. The analysis for productions and monosaccharide compositions indicated that EPS from two diatoms were different in terms of the productions, distributions, and monomer compositions. Amphora sp. produced more (1.5-fold) total exopolysaccharides, but less (<0.4-fold) BF-TB-EPS than Stauroneis sp. The monosaccharides of the EPS from Amphora sp. were more diverse than those of Stauroneis sp., with 13 and 10 monomers, respectively. Neutral sugars, Glc, Xyl and Man, were abundant in Stauroneis sp., while Gal, Glc and Xyl were rich in Amphora sp. Uronic acid and hexosamine were present in all fractions of two diatoms, especially Glc-A being the most abundant monomer in SL-EPS of Amphora sp. It was proposed that the high content of uronic acid (especially Glc-A) might be crucial for the strong biofilm formation abilities of Amphora sp.

Exopolysaccharides from Microalgae and Cyanobacteria: Diversity of Strains, Production Strategies, and Applications

“…[ 35 ], Staurastrum orbiculare [ 36 ], Amphora sp. [ 37 ], Anabaena spiroides [ 38 ], Aphanothece halophytica [ 39 ], Arthrospira platensis [ 40 ], Cyanospira capsulata [ 41 ], Fischerella maior [ 42 ], Corynoplastis japonica , and Neorhodella cyanea [ 32 ]. In addition, some other uronic acids have been occasionally described, such as mannuronic acid, detected only in the EPSs of Heterosigma akashiwo [ 43 ].…”

“…and Amphora sp. [ 37 ], Amphora salina and Triceratium dubium [ 47 ], Aulacoseira granulate and Microcystis aeruginosa [ 38 ], Thalassiosira sp. [ 48 ], Toypothrix tenuis [ 49 ], Calothrix sp.…”

A methodological review on the characterization of microalgal biofilm and its extracellular polymeric substances

“…proposed stronger biofilm adhesion ability than Stauroneis sp. (Jin et al, 2018). High-molecular weight carbohydrates can be easily extracted with ethanol precipitation and centrifuged to remove the water-insoluble substances such as glycolipids (Takahashi et al, 2009).…”

Physiology of microalgal biofilm: a review on prediction of adhesion on substrates

“…Strong adhesion usually consists of huge compounds in which their macromolecules can come in close contact with a wide range of surfaces [11]. There were scientific reports on the isolation and partial chemical analysis of EPS from the microalgae to date, especially extracellular polysaccharides because it is a major component in the biofilm matrix [57][58][59]. In a biofilm, the functional groups of exopolysaccharides depict strong affinity toward different dissolved organic matters and metal ions [60].…”

“…Among those monosaccharides, glucose concentration was the highest as compared with the others [ 62 ]. In the biofilm cells of Amphora sp., glucose was the most abundant followed by galactose, mannose and rhamnose with mole percentage over 10% and xylose, fucose and N-acetyl-D-glucosamine in mole percentage less than 5% [ 57 ]. In the same study, the biofilm cells of Stauroneis sp.…”