A new tool to detect high viscous exopolymers from microalgae

Abstract

Microalgae are microorganisms often surrounded by a slime layer made of secreted polymeric substances sometimes including polysaccharides. These polysaccharides, weakly described in the literature, can constitute value-added molecules in several industrial areas. The aim of this article is to show that a new tool, the BioFilm Ring Test®, can be used to detect viscous microalgal exopolymers. Two red microalgal strains (Rhodella violacea and Porphyridium purpureum), one cyanobacterium (Arthrospira platensis) and their excreted polymeric fractions were studied. R. violacea and P. purpureum induced a positive response with the BioFilm Ring Test® contrary to A. platensis. Finally, the understanding of the fractions viscosity involvement in the BRT response was performed by a rheological study.

Study of the Adhesion of Clinical Strains of <i>Staphylococcus aureus</i> on an Abiotic Surface Using the Biofilm Ring Test®

“…Cations (calcium, magnesium, manganese) interfered with the behavior of the beads in the BFRT ® and decreased the BFI. Similar artefactual interactions have also been described with pronase [37] or with culture media with high ionic strength [38]. Such interaction has also been observed with antimicrobial cationic peptides derived from cathelicidin and which, at neutral pH, have many positive charges (C. Nagant, personal communication).…”

Effect of proteases against biofilms of Staphylococcus aureus and Staphylococcus epidermidis

“…epidermidis and Staph. aureus aureus (Chavant et al 2007;Badel et al 2008Badel et al , 2011a. BRT is a powerful analytical tool that enables quick and convenient screening of anti-biofilm agents based on the mobility of magnetic beads in the bacterial culture medium.…”

Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae

“…It is well known that hydrocolloid solutions of sPS, produced by red microalgae and the cyanobacterium A. platensis , present a non-Newtonian behaviour, as their viscosity depends negatively on the shear strain rate, i.e. , decreases with the increase of this last parameter [50,72,75,81,84,85], thus showing that it is a pseudoplastic compound [86] with a strong shear-thinning behaviour [75]. However, Sun et al [58] showed that fragments of EPS from Porphyridium had a different rheological behaviour, depending on the degree of degradation, sometimes exhibiting typical characteristics of Newtonian fluids.…”