Effects of surface material on growth pattern and bioactive exopolymers production of intertidal cyanobacteria Phormidium sp.

Abstract

A novel approach applying a conico-cylindrical flask (CCF) was used to study the growth of two morphologically identical <em>Phormidium </em>strains namely AP3 and AP9F. Further, the monosaccharide composition of the exopolysaccharide (EPS), its production, applicability in industrial processes and biological activity were evaluated. These evaluations were performed by employing contrasting cultivation modes (biofilm or planktonic) and different surface materials (hydrophobic polymethyl methacrylate (PMMA) and hydrophilic glass (G). Biofilm formation was seen to be elevated in PMMA-CCF cultivated <em>Phormidium</em> AP3 and AP9F than G-CCF mode. Among the two surface materials tested <em>Phormidium</em> AP3 and AP9F produced the highest amount of planktonic biomass in PMMA-CCF than in G-CCF mode. Average values of biofilm capsular/bound polysaccharide and polysaccharide released by cell suspension of <em>Phormidium</em> AP3 and AP9F were elevated in PMMA-CCF compared to the G-CCF setup. Protein concentrations in released polysaccharide (RPS) and biofilm of PMMA-CCF were higher in the <em>Phormidium </em>AP3 and AP9F when compared to the G-CCF cultivation. The antimicrobial, emulsifying and flocculating activities of EPS were assessed using standard assays.