AUTHOR=Ngo Trang T. , Nguyen Bich-Loan T. , Duong Tuan A. , Nguyen Thu-Huyen T. , Nguyen Thanh L. , Kieu Kien T. , Do Minh-Hanh T. , Nguyen Sang V. , Thang Nguyen Dinh , Pham Hang T. L. 

TITLE=Polyphasic evaluation and cytotoxic investigation of isolated cyanobacteria with an emphasis on potent activities of a Scytonema strain

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1025755

DOI=10.3389/fmicb.2022.1025755

ISSN=1664-302X

ABSTRACT=<p>Cyanobacteria are phototrophic organisms widely found in most types of natural habitats in the tropical regions of the world. In this study, we isolated and identified cyanobacterial strains from paddy soil in Hanoi (Vietnam) and investigated their cytotoxic activities. Five isolated cyanobacterial strains showed distinctive profiles of gene sequences (rRNA 16S and <italic>rbcL</italic>), phylogenetic placements, and morphological characteristics. Based on the polyphasic evaluation, they were classified as <italic>Scytonema bilaspurense</italic> NK13, <italic>Hapalosiphon welwitschii</italic> MD2411, <italic>Aulosira</italic> sp. XN1103, <italic>Desikacharya</italic> sp. NS2000, and <italic>Desmonostoc</italic> sp. NK1813. The cytotoxic screening revealed that the extract of strain <italic>Scytonema bilaspurense</italic> NK13 exhibited potent cytotoxic activities against four human cell lines of HeLa cells, OVCAR-8 cells, HaCaT cells, and HEK-293T cells, with IC<sub>50</sub> values of 3.8, 34.2, 21.6, and 0.6 μg/mL, respectively. This is the first time a well-classified <italic>Scytonema</italic> strain from tropical habitat in Southeast Asia has been recognized as a potential producer of cytotoxic compounds.</p>