Cyanobacteria are a group of prokaryotic microorganisms including both coccoid and filamentous forms. Their prokaryotic nature, the presence of many cryptic species and the coexistence of different classification systems make particularly difficult the taxonomic identification of these organisms. Currently, more and more authors agree that a polyphasic approach is necessary to correctly identify cyanobacterial strains (Komárek 2010, Moro et al. 2010, Sciuto et al. 2011). In the light of their capability to produce bioactive compounds and since some studies suggest that the production of metabolites by cyanobacteria is species‐ specific or even strain‐specific (Biondi et al. 2008, Sharp et al. 2009), it is important to know the cyanobacterial composition of certain environments, such as thermal springs exploited for therapeutic purposes. For several years our laboratory has been involved in the characterization of cyanobacteria colonizing the Euganean thermal District (Padova, Italy) (Ceschi‐Berrini et al. 2004, Moro et al. 2007a, 2007b, 2010), highlighting how these organisms are responsible for most of the mud therapeutic properties. Particularly, a filamentous strain, isolated from this environment and characterized as Phormidium sp. ETS‐05 (where the acronym ‘ETS’ stands for ‘Euganean Thermal Springs’), showed high contents of polyunsaturated fatty acids with anti‐inflammatory properties higher than those of other commonly used pharmaceuticals (Lalli et al. 2004). Ischia thermal District (Naples, Italy), another Italian thermal environment, is known since ancient time and it is visited by thousands of people for therapeutic purposes every year. However, scarce information is available on the bioglea growing in this environment and on its therapeutic potential. For these reasons, and in order to draw a parallel to the Euganean thermal District, recently we have started a study on the biodiversity of Ischia thermal springs. This survey has led to a first publication on a filamentous cyanobacterium, named Protolyngbya sp. strain ITD‐01 (where the acronym ‘ITD’ indicates ‘Ischia Thermal District’) (Sciuto et al. 2011). Here we present results about another cyanobacterium isolated from Ischia District, the coccoid strain ITD‐02. The performed molecular and phylogenetic analyses underlined how this organism is strictly related to another coccoid cyanobacterium, isolated from the Euganean thermal District and previously characterized as Cyanobacterium aponinum PCC 10605 (Moro et al. 2007b). From this starting point, we have carried out a polyphasic approach to compare the two organisms, including morphological, ultrastructural, biochemical, and physiological analyses. The obtained data allow us to ascribe strain ITD‐02 to the genus Cyanobacterium, but the question regarding its belonging to the species C. aponinum or to a different species is still open.
Polyphasic comparison of two cyanobacterial strains from different Italian thermal districts
Sciuto K
Primo
;
2012
Abstract
Cyanobacteria are a group of prokaryotic microorganisms including both coccoid and filamentous forms. Their prokaryotic nature, the presence of many cryptic species and the coexistence of different classification systems make particularly difficult the taxonomic identification of these organisms. Currently, more and more authors agree that a polyphasic approach is necessary to correctly identify cyanobacterial strains (Komárek 2010, Moro et al. 2010, Sciuto et al. 2011). In the light of their capability to produce bioactive compounds and since some studies suggest that the production of metabolites by cyanobacteria is species‐ specific or even strain‐specific (Biondi et al. 2008, Sharp et al. 2009), it is important to know the cyanobacterial composition of certain environments, such as thermal springs exploited for therapeutic purposes. For several years our laboratory has been involved in the characterization of cyanobacteria colonizing the Euganean thermal District (Padova, Italy) (Ceschi‐Berrini et al. 2004, Moro et al. 2007a, 2007b, 2010), highlighting how these organisms are responsible for most of the mud therapeutic properties. Particularly, a filamentous strain, isolated from this environment and characterized as Phormidium sp. ETS‐05 (where the acronym ‘ETS’ stands for ‘Euganean Thermal Springs’), showed high contents of polyunsaturated fatty acids with anti‐inflammatory properties higher than those of other commonly used pharmaceuticals (Lalli et al. 2004). Ischia thermal District (Naples, Italy), another Italian thermal environment, is known since ancient time and it is visited by thousands of people for therapeutic purposes every year. However, scarce information is available on the bioglea growing in this environment and on its therapeutic potential. For these reasons, and in order to draw a parallel to the Euganean thermal District, recently we have started a study on the biodiversity of Ischia thermal springs. This survey has led to a first publication on a filamentous cyanobacterium, named Protolyngbya sp. strain ITD‐01 (where the acronym ‘ITD’ indicates ‘Ischia Thermal District’) (Sciuto et al. 2011). Here we present results about another cyanobacterium isolated from Ischia District, the coccoid strain ITD‐02. The performed molecular and phylogenetic analyses underlined how this organism is strictly related to another coccoid cyanobacterium, isolated from the Euganean thermal District and previously characterized as Cyanobacterium aponinum PCC 10605 (Moro et al. 2007b). From this starting point, we have carried out a polyphasic approach to compare the two organisms, including morphological, ultrastructural, biochemical, and physiological analyses. The obtained data allow us to ascribe strain ITD‐02 to the genus Cyanobacterium, but the question regarding its belonging to the species C. aponinum or to a different species is still open.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
