Diversity, Cyanotoxin Production, and Bioactivities of Cyanobacteria Isolated from Freshwaters of Greece
Spyros Gkelis,
Manthos Panou,
Despoina Konstantinou,
Panagiotis Apostolidis,
Antonia Kasampali,
Sofia Papadimitriou,
Dominiki Kati,
Giorgia Maria Di Lorenzo,
Stamatia Ioakeim,
Sevasti-Kiriaki Zervou,
Christophoros Christophoridis,
Theodoros M. Triantis,
Triantafyllos Kaloudis,
Anastasia Hiskia,
Minas Arsenakis
Affiliations
Spyros Gkelis
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Manthos Panou
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Despoina Konstantinou
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Panagiotis Apostolidis
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Antonia Kasampali
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Sofia Papadimitriou
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Dominiki Kati
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Giorgia Maria Di Lorenzo
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Stamatia Ioakeim
Department of Botany, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Sevasti-Kiriaki Zervou
Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research “Demokritos”, Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
Christophoros Christophoridis
Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research “Demokritos”, Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
Theodoros M. Triantis
Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research “Demokritos”, Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
Triantafyllos Kaloudis
Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research “Demokritos”, Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
Anastasia Hiskia
Laboratory of Photo-Catalytic Processes and Environmental Chemistry, Institute of Nanoscience & Nanotechnology, National Center for Scientific Research “Demokritos”, Patriarchou Grigoriou & Neapoleos, Agia Paraskevi, 15341 Athens, Greece
Minas Arsenakis
Department of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece
Cyanobacteria are a diverse group of photosynthetic Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against a broad spectrum of organisms and cell lines. In this study, 29 strains isolated from freshwaters in Greece were classified using a polyphasic approach and assigned to Chroococcales, Synechococcales, and Nostocales, representing 11 genera and 17 taxa. There were good agreements between 16S ribosomal RNA (rRNA)−cpcBA−internal genetic spacer (IGS) characterization and morphological features, except for the Jaaginema−Limnothrix group which appears intermixed and needs further elucidation. Methanol extracts of the strains were analyzed for cyanotoxin production and tested against pathogenic bacteria species and several cancer cell lines. We report for the first time a Nostoc oryzae strain isolated from rice fields capable of producing microcystins (MCs) and a Chlorogloeopsis fritschii strain isolated from the plankton of a lake, suggesting that this species may also occur in freshwater temperate habitats. Strains with very high or identical 16S rRNA gene sequences displayed different antibacterial and cytotoxic activities. Extracts from Synechococcus cf. nidulans showed the most potent antibacterial activity against Staphylococcus aureus, whereas Jaaginema sp. strains exhibited potent cytotoxic activities against human colorectal adenocarcinoma and hepatocellular carcinoma cells. Jaaginema Thessaloniki Aristotle University Microalgae and Cyanobacteria (TAU-MAC) 0110 and 0210 strains caused pronounced changes in the actin network and triggered the formation of numerous lipid droplets in hepatocellular carcinoma and green monkey kidney cells, suggesting oxidative stress and/or mitochondrial damage leading to apoptosis.