Optimization, characterization, and flow properties of exopolysaccharides produced by the cyanobacteriumLyngbya stagnina

Abstract

The exopolysaccharides produced by the cyanobacterium Lyngbya stagnina have been characterized. Maximum amounts of EPS (142.4 µg EPS ml(-1) culture) were obtained during the stationary phase of growth and rate of EPS production was maximum during late phase of growth. When medium was supplemented with 85 mM NaCl, the organism produced three times more EPS compared to EPS produced by control cultures. TLC and HPLC analysis of the EPS hydrolysate revealed heteropolysaccharide nature with presence of four neutral sugars and galacturonic acid. Presence of high amounts of galacturonic acid in EPS indicated its polyanionic character. Aqueous dispersions of EPS showed non-Newtonian, pseudoplastic behavior and its viscosity was found to be quite stable with time. The viscosity data of aqueous dispersions of EPS at different temperatures (20-50 °C) were fitted into rheological models. The viscosity of EPS varied with pH, being highest at pH 10 and lowest at pH 6. Both divalent and monovalent cations caused increase in viscosity of EPS solution. The results suggest that EPS of this organism may find application in food industry.

Isolation, characterization and localization of extracellular polymeric substances from the cyanobacteriumArthrospira platensisstrain MMG-9

“…REPS, LEPS and TEPS, revealed the ratio in which the component monosaccharides were present in the three operational fractions to be different, with seven out of eight tested monosaccharide residues detected in the TEPS fraction. Although a wide range of analytical techniques have been used to study the monosaccharide composition of EPS, including TLC, HPLC, GC and GC-MS, these techniques can only detect four-eight residues in a single run (Saravanan & Jayachandran, 2008;Jindal et al, 2013;Ohki et al, 2014). Glucose is the predominant monosaccharide in the majority of cyanobacterial released polysaccharides (REPS); an exception is the REPS of Anabaena sphaerica which contains galactose as the main sugar (Li et al, 2001).…”

Potential Biotechnological Applications of Cyanobacterial Exopolysaccharides

“…The rheological properties of EPSs produced by the cyanobacterium Lyngbya stagnina have been studied by Jindal and coauthors. [20]. Shear-thinning pseudoplastic behavior of EPS of L. stagnina is similar to commercial gum Xanthan which is widely useful in the food industry.…”

Continuous cultivation of a thermophilic bacteriumAeribacillus pallidus418 for production of an exopolysaccharide applicable in cosmetic creams

“…The flow behaviour of fluids depends on variables such as shear rate, temperature, pressure, and time of shearing (Jindal et al . ). For most non‐Newtonian fluids, the viscosity decreases with an increase in shear rate, giving rise to what is known as pseudoplasticity or shear thinning behaviour.…”