Ozone enhanced production of potentially useful exopolymers from the cyanobacterium Nostoc muscorum

Publication date: Available online 27 January 2020Source: Polymer TestingAuthor(s): Dharitri Borah, Gayathri Rethinam, Subramanian Gopalakrishnan, Jayashree Rout, Naiyf S. Alharbi, Sulaiman Ali Alharbi, Thajuddin NooruddinAbstractExtracellular polysaccharides (EPS) from Nostoc muscorum, a heterocystous, filamentous cyanobacterium isolated from a jhumland (shifting cultivation) soil of Assam, North-East India, was physico-chemically characterized to find out its potential applications and to improve its production with some stress source like ozone. Using Response Surface Methodology (RSM), EPS production was improved. Accordingly, with magnesium sulfate (MgSO4·7H2O) at 62 mg L−1, Sodium Chloride (NaCl) at 58 mg L−1 and 56 mg L−1 di-potassium hydrogen phosphate (K2HPO4), a yield of 126.73 μg mL−1 of EPS in 12 days was obtained which was four-fold higher than un-optimised control. An important finding of this study is that EPS production could be further enhanced by over 50% with a mild stress by a strong oxidizing agent ozone (O3). Physico-chemical properties of this Ozone induced EPS was evaluated and found identical to uninduced EPS. EPS was composed of the hexoses- Glucose (14.80%), Galactose (18.01%) and Mannose (12.64%), the pentoses- Arabinose (17.86%) and Xylose (11.66%), the deoxyhexose- Fucose (12.53%) and Rhamnose (12.50%). Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) analysis revealed the presence of the f...
Source: Polymer Testing - Category: Chemistry Source Type: research