Anatomizing extracellular polymer of Calothrix desertica with its anti-oxidation and anti-nutrient profiling

Abstract

Calothrix desertica having a semilunar apical heterocyst is proficient at excreting 1.2 g/L of extracellular polymers (EPsC) in 45 days. The refined EPsC constitutes 430 mg/g of glycogen, 390 mg/g of protein, and 14.6 mg/g of glycoproteins (GPs). The glycoprotein estimation of EPsC was performed by two step hydrolysis methods with H2SO4. The peak between 10 mAU to 20 mAU in HPLC, 1400 cm-1 to 1700 cm-1 in FTIR, and 40kDa- 35kDa bands in SDS-PAGE authenticates the presence of glycoproteins in the EPsC. The EPsC agglomerate of 1000 nm to 3000 nm size with a Zeta potential of -20 mV to 5 mV was determined using DLS. Further EPsC of nanosizes of 30 nm to 150 nm in 50,000 X and 20 nm to 40 nm in 60,000 X was measured using FE- SEM. The DPPH assay and H2O2 scavenging assay showed 73.1% and 70.8% of anti-oxidant activity in EPsC, which is coequally efficient as standard gallic acid. EPsC biopolymer can also be used as a potential reducing agent, as per the anti-nutrient activity studies.