Journal of Bacteriology & Parasitology

A proposal for the unification of two strains of cyanobacteria genus Nostoc to the same species

7^th World Congress on Microbiology

November 28-29, 2016 Valencia, Spain

Bahareh Nowruzi, Ramezan-Ali Khavari-Nejad, Taher Nejadsattari, Karina Sivonen and David P Fewer

Islamic Azad University, Iran
Kharazmi University, Iran
University of Helsinki, Finland

Posters & Accepted Abstracts: J Bacteriol Parasitol

Abstract:

Studies of cyanobacteria are important to the global scientific community because of their ecological and applied importance. Amongst the different cyanobacterial orders, the Nostocales and Stigonematales orders are especially important as they fix atmospheric nitrogen and thus contribute to the fertility of agricultural soils worldwide. However, in spite of their ecological importance and environmental concerns, their identification and taxonomy is still problematic and confusing, often being based on current morphological and physiological studies, which generates confusing classification systems based on plastic characters that vary with the environmental and cultural conditions. The present research aimed to investigate through a polyphasic approach, the differences in morphological and genotypic features of two cyanobacteria strains isolated from paddy fields of Iran, belonging to the family Nostocaceae (subsection IV. I). Based on the description of the morphology provided by Desikachary (1959), the two strains were identified as Nostoc ellipsosporum and Nostoc muscorum. Challenges arose when the two Nostoc strains could not be discriminated by 16S rRNA and ITS genes sequencing. The results of sequencing of the cloned bacterial 16S rRNA fragment strongly indicated that the current morphological classification of the two Nostoc species is invalid. Moreover, phylogenetic study of these two Nostoc strains has demonstrated that genetic relationships are in conflict with the morphological classification. Besides, after doing DNA-DNA re-association experiments, we concluded that the two Nostoc strains investigated might possibly be united into one species.

Biography :

Email: bahare77biol@yahoo.com