V. Miriam Sheba, C. Prasana Kumar, B. Balaji Prasath and T. Nargis Begum
Abstract
Mangrove ecosystems are highly productive areas significantly impacted by tides, environmental conditions, and human activity. Cyanobacteria, a photoautotrophic phylum, holds significant importance due to its long evolutionary history. Cyanobacteria is known for its wide range of morphological, physiological, and genetic diversity. The traditional method of identification, which depends on the morphological characteristics may not provide accurate resolution due to closely related species. Hence a polyphasic approach is carried out in this study which involves the combination of methods including morphological, physiological and molecular techniques. Cyanobacterial strains from Muthukuda mangrove ecosystem on the southeastern coast of India, when examined under a microscope, had numerous unicellular and filamentous cyanobacteria from the orders Chroococcales sp, Synechococcales sp., Chroococcales sp, and Oscillatoriales sp, according to the observations. To ensure the purity of the cyanobacterial strain under the microscope, meticulous examination of cellular morphology and the absence of any contaminating organisms were conducted. DNA was extracted from the purified cyanobacteria strains and amplified with cyanobacteria-specific 16S rRNA genes, sequencedand submitted in NCBI. The relationship between the cyanobacterial isolates was monitored by constructing a phylogenetic tree. Both morphological and molecular analysis was compared and the results complimented each other. Using the polyphasic approach, our four cyanobacterial strains were identified: P. mucicola, P. foetida, Gloeocapsea sp., and S. elongatus. This study highlights and insists on the polyphasic identification of cyanobacterial species, as accurate identification is essential for isolating and characterizing cyanobacterial strains with desired traits for understanding diversity and distribution. This comprehensive approach not only enhances our understanding of cyanobacterial ecology but also provides valuable insights for the sustainable management of aquatic environments and the development of biotechnological solutions leveraging cyanobacterial capabilities.