Production of Exopolysaccharide from an Endophytic Fusarium sp. GloS2 and Documentation of its In vitro Antioxidative Potentialities

This study investigated the exopolysaccharide (EPS) producing ability of an endophytic fungus GloS2. It involved examining various aspects, including identifying and cultivating endophytic fungi, producing and characterizing EPS, optimizing the production process, and evaluating their antioxidant properties. The fungus GloS2 (Fusarium sp.) was optimized for EPS synthesis through one variable at a time (OVAT) and response surface methodology (RSM) to determine the optimal culture environment and growth medium components, resulting in the maximum EPS production of 5.39 gL-1. Furthermore, the EPS exhibited significant antioxidant activity with a greater IC50 value (15.05 ± 0.51 µg mL-1) in the hydroxyl radical scavenging assay. The Fourier Transform Infrared Spectral analysis indicates the presence of chemical groups i.e., O-H, C-H, C-O-H, and C-O. Additionally, gas chromatography-mass spectrometry (GC-MS) analysis revealed that erythrose, fructose, and mannose were the major monosaccharide components, with a molar proportion of nearly 1:1:1 and a molecular mass of ~1.12 x 105 Da. Moreover, the structural characterization of EPS has confirmed the existence of α-glycosidic linkage along with β-D-galactopyranosyl moieties and substituted glucose residues.