Isolation and Characterization of Exopolysaccharides Produced by the Cyanobacterium Limnothrix redekei PUPCCC 116

Abstract

Limnothrix redekei PUPCCC 116, a filamentous cyanobacterium, has been identified through 16S rRNA gene sequencing. Exopolysaccharides (EPS) of this organism have been isolated and characterized chemically, and its rheological properties were compared with commercial xanthan. The organism produced 304 microg EPS/ml culture in 21 days. The rate of EPS production was maximum (313 microg EPS/mg protein/day) during the initial days of growth, and it decreased to 140 microg EPS/mg protein/day during 18-21 days of growth. Chemical analysis of EPS revealed the presence of glucose/mannose, ribose, rhamnose, and uronic acid. Fourier transformed infrared spectrum of EPS further revealed the presence of methyl and carboxyl groups besides C-N groups indicating the presence of peptidyl moieties. Elemental analysis of EPS showed the presence of 4.97% N. The organism under continuous light produced 102% more EPS compared to when grown under a light/dark cycle of 14/10 h. The rheological properties of EPS were comparable with commercial xanthan gum.

Extracellular Polymeric Substance (EPS) Production by <i>Nostoc minutum</i> under Different Laboratory Conditions

“…The viscosity of N. minutum EPS showed a decrease with an increase in the shear rate. Such rheological behaviour is the characteristic of a typical pseudoplastic non-Newtonian fluid [30] and agrees with results reported by Khattar et al [31].…”

Isolation and physico-chemical characterisation of extracellular polymeric substances produced by the marine bacteriumVibrio parahaemolyticus

“…Lyophilised samples were dissolved in distilled water (0.4% w/v) (Khattar et al 2010), and their viscosities Biofouling 311…”

Characterization and Optimization of Bioflocculant Exopolysaccharide Production by Cyanobacteria Nostoc sp. BTA97 and Anabaena sp. BTA990 in Culture Conditions

“…Oscillatoria formosa was reported to produce 334.8 μg ml −1 in 24 days [29]. Another filamentous cyanobacterium, Limnothrix redekei PUPCCC 116, produced 304 μg ml −1 of exopolysaccharides [30]. In other reports, strains of Cyanothece, Nostoc calcicola, and Anabaena were reported to produce 1,770, 700, and 55 mg l −1 of EPS, respectively [31][32][33].…”