| Title | Grazing-induced Synechococcus microcolony formation: Experimental insights from two freshwater phylotypes |
| Abstract | Freshwater cyanobacteria of the genus Synechococcus are ubiquitous and organized either as single cells of diverse morphology or as microcolonies of different size. We studied the formation of microcolonies induced by the mixotrophic nanoflagellate Poterioochromonas sp. grazing on two Synechococcus strains belonging to phylotypes with different content of phycobiliproteins (PE: phycoerythrin-rich cells, L.Albano Group A; PC: phycocyanin-rich cells, MW101C3 Group I). The quantitative variations in cell abundance, morphological and physiological conditions were assessed on short-term incubations in semi-continuous cultures, single culture (PE, PC) and co-culture (PE+PC), with and without predators, by flow cytometry, and PhytoPAM. Under grazing pressure, we observed that (i) the abundance of PE single cells decreased over time with a concomitant formation of PE microcolonies; (ii) in PC single cultures, no significant variation in single cells was found and microcolonies did not form; (iii) both PE and PC formed monoclonal microcolonies in co-culture; (iv) PC cells increased the photosynthetic efficiency of the PSII (higher Fv/Fm) in co-culture. In the aftermath of microcolony formation as a predation-induced adaptation, our findings indicated a different response of Synechococcus phylotypes potentially co-existing in natural environment and the importance of their interaction. |
| Source | FEMS microbiology, ecology (print) 92 |
| Keywords | CyanobacteriaMicrocolonies |
| Journal | FEMS microbiology, ecology (print) |
| Editor | Elsevier, Amsterdam, Paesi Bassi |
| Year | 2016 |
| Type | Articolo in rivista |
| DOI | 10.1093/femsec/iw154 |
| Authors | Callieri C.; Amalfitano S.; Corno G.; Bertoni R. |
| Text | 372404 2016 10.1093/femsec/iw154 Scopus 2 s2.0 84992732430 Cyanobacteria Microcolonies Grazing induced Synechococcus microcolony formation Experimental insights from two freshwater phylotypes Callieri C.; Amalfitano S.; Corno G.; Bertoni R. Institute of Ecosystem Study, CNR ISE, Verbania, 28922, , Italy; Water Research Institute, CNR, Monterotondo, Rome, 00015, , Italy Freshwater cyanobacteria of the genus Synechococcus are ubiquitous and organized either as single cells of diverse morphology or as microcolonies of different size. We studied the formation of microcolonies induced by the mixotrophic nanoflagellate Poterioochromonas sp. grazing on two Synechococcus strains belonging to phylotypes with different content of phycobiliproteins PE phycoerythrin rich cells, L.Albano Group A; PC phycocyanin rich cells, MW101C3 Group I . The quantitative variations in cell abundance, morphological and physiological conditions were assessed on short term incubations in semi continuous cultures, single culture PE, PC and co culture PE PC , with and without predators, by flow cytometry, and PhytoPAM. Under grazing pressure, we observed that i the abundance of PE single cells decreased over time with a concomitant formation of PE microcolonies; ii in PC single cultures, no significant variation in single cells was found and microcolonies did not form; iii both PE and PC formed monoclonal microcolonies in co culture; iv PC cells increased the photosynthetic efficiency of the PSII higher Fv/Fm in co culture. In the aftermath of microcolony formation as a predation induced adaptation, our findings indicated a different response of Synechococcus phylotypes potentially co existing in natural environment and the importance of their interaction. 92 Published version http //www.scopus.com/record/display.url eid=2 s2.0 84992732430 origin=inward Articolo in rivista Elsevier 0168 6496 FEMS microbiology, ecology print FEMS microbiology, ecology print FEMS microbiol. ecol. print FEMS microbiology, ecology. print Federation of European Microbiological Societies microbiology, ecology print roberto.bertoni BERTONI ROBERTO cristiana.callieri CALLIERI CRISTIANA stefano.amalfitano AMALFITANO STEFANO gianluca.corno CORNO GIANLUCA |
