Diversity analysis of cyanobacterial flora from the Tatapani Hot Spring of Chhattisgarh and exploration of their industrially as well as environmentally valuable properties

Abstract

The present study investigates the cyanobacterial diversity of Tatapani hot spring, Chhattisgarh, India, using a polyphasic approach, their pigment system, biofuel properties and ability to bioremediate emerging pollutant triclosan. While the microscopic analyses of the natural samples reflected high cyanobacterial diversity with all morpho-forms, physicochemical studies revealed temperature being the major factor affecting the cyanobacterial distribution in the hot spring. Among the 22 collected cyanobacterial samples, 14 were grown successfully under laboratory conditions and 10 of them showed optimum growth at 45 °C. However, four strains displayed preference for lower temperature (27 °C) for optimum growth. The polyphasic characterization of 14 strains revealed that all the thermophiles belonged to the genus Mastigocladus whereas the strains Sytonema sp. TPJ-3, Calothrix sp. TPB-2, Westiellopsis sp. TPR-29 and Desikacharya sp. TPB-4 constituted the group of mesophiles. Calothrix sp. TPB-2 was identified as a novel genus (Neocalothrix thermalis) based on distinct morphology and phylogenetic position with unique ITS folding pattern. Additionally, our study disclosed the production of comparatively higher amounts of pigments and medium chain length fatty acids (C16 to C18) by the thermophilic strains, which indicated their potential to be used as feedstocks for pigments and biofuel production respectively. Although the triclosan bioremediation study reflected considerable triclosan removal efficiencies of all the strains, most impressive results were observed in case of Westiellopsis sp. TPR-29 (93.08 %) and Mastigocladus sp. TA-8 (91.92 %). Moreover, the in-silico study-based revelation of high triclosan binding ability of cyanobacterial laccase (−5.8 and − 5.4 kcal/mol) and catechol 2,3-dioxygenase (−5.9 and − 6.0 kcal/mol) suggested the probable triclosan degrading potential of Westiellopsis and Mastigocladus. Conclusively, the Tatapani hot spring represents a unique environment with the dominance of true-branched heterocytous thermophilic cyanobacteria that have enormous potential to remove triclosan and produce high amounts of pigments and medium chain length fatty acids.