Identification of Phormidium sp, (kützing ex Gomont 1892): a potential exopolymer for effective bioremediation

Abstract

The autotrophic cyanobacterium Phormidium sp. is filamentous, blue-green, sheath-prominent, and trichome-constricted. DNA barcoding of the 16S rRNA sequence was submitted to NCBI-GenBank under the accession number MW436689, with a similarity of 97–99% with varied sequences. The Phormidium sp. barcode region had a high G + C content (52.7%). An investigation is underway to extract and characterize exocellular polymeric substances from Phormidium sp. (EPS-P) for efficacy analysis. FTIR, GC-MS, and NMR were used to characterize (EPS-P). FTIR suggests the presence of hydroxy groups (O-H moieties) and amine salts (N-H). GCMS shows D-galactose, L-rhamnose, D-mannose, uronic acid, and D-glucuronic acid. The specific chemical shifts could be identified in the 1H NMR spectra. EPS has been used in a variety of industrial and environmental applications. The ability to emulsify EPS-P (0.1%) was analyzed with various oils. The emulsifying index (EI) was observed to be gingelly oil > brake oil > neem oil > coconut oil > petrol oil > diesel oil (EI24-EI120 hours). EPS-P performed bio-flocculating activity at various concentrations (10-50 mg mL1). The flocculating activity of EPS-P shows 89.5% at 50 mg ml−1. The EPS-P could be an excellent candidate for bio-flocculation and bio-emulsification aspects that are also eco-friendly.