Abstract Title
Phylogenetic analysis of cyanobacteria based on two novel molecular markers, implicated in the nitrogenase biosynthesis
Start Date
23-5-2022 5:45 PM
End Date
23-5-2022 7:00 PM
Abstract
The characterization of bloom cyanobacteria communities remains challenging, as taxonomy of several cyanobacterial genera is still unresolved, especially within Nostocales taxa. Nostocales cyanobacteria are capable of nitrogen fixation; nitrogenase genes are grouped into operons and are located in the same genetic locus. Previous studies demonstrated, that the divergence rate of nitrogenase structural gene (nifH) in cyanobacteria appear to be in congruence with that of 16S rRNA. However, there is no available information regarding the phylogeny of structural genes of the nitrogenase cluster. In this context, we developed a set of degenerate PCR primers for the amplification of nifE and nifN, two understudied structural nitrogenase genes. Successful phylogenetic analyses of nifE and nifN genes were carried out on thirty (30) Nostocales cyanobacteria strains, representing the genera Anabaena, Anabaenopsis, Calothrix, Chlorogloeopsis, Desmonostoc, Dolichospermum, Komarekiella, Nodularia, Nostoc, Raphidiopsis, Sphaerospermopsis, and Trichormus. A similar phylogenetic pattern between nifE/nifN, nifH, and 16S rRNA was observed, while phylogeny based on the nitrogenase structural genes nifE/nifN showed a higher resolution between Nostocales cyanobacteria and their lifestyle. In this study, we propose the use of two novel molecular markers, which could provide better insights in the taxonomy of Nostocales.
Phylogenetic analysis of cyanobacteria based on two novel molecular markers, implicated in the nitrogenase biosynthesis
The characterization of bloom cyanobacteria communities remains challenging, as taxonomy of several cyanobacterial genera is still unresolved, especially within Nostocales taxa. Nostocales cyanobacteria are capable of nitrogen fixation; nitrogenase genes are grouped into operons and are located in the same genetic locus. Previous studies demonstrated, that the divergence rate of nitrogenase structural gene (nifH) in cyanobacteria appear to be in congruence with that of 16S rRNA. However, there is no available information regarding the phylogeny of structural genes of the nitrogenase cluster. In this context, we developed a set of degenerate PCR primers for the amplification of nifE and nifN, two understudied structural nitrogenase genes. Successful phylogenetic analyses of nifE and nifN genes were carried out on thirty (30) Nostocales cyanobacteria strains, representing the genera Anabaena, Anabaenopsis, Calothrix, Chlorogloeopsis, Desmonostoc, Dolichospermum, Komarekiella, Nodularia, Nostoc, Raphidiopsis, Sphaerospermopsis, and Trichormus. A similar phylogenetic pattern between nifE/nifN, nifH, and 16S rRNA was observed, while phylogeny based on the nitrogenase structural genes nifE/nifN showed a higher resolution between Nostocales cyanobacteria and their lifestyle. In this study, we propose the use of two novel molecular markers, which could provide better insights in the taxonomy of Nostocales.