Open AccessLife cycle as a stable trait in the evaluation of diversity of Nostoc from biofilms in rivers
Author(s) -
Mateo Pilar,
Perona Elvira,
Berrendero Esther,
Leganés Francisco,
Martín Marta,
Golubić Stjepko
Publication year - 2011
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2010.01040.x
Subject(s) - biology , nostoc , 16s ribosomal rna , phylogenetic tree , trichome , biofilm , botany , trait , strain (injury) , phylogenetic diversity , ecology , evolutionary biology , gene , genetics , bacteria , cyanobacteria , anatomy , computer science , programming language
The diversity within the genus Nostoc is still controversial and more studies are needed to clarify its heterogeneity. Macroscopic species have been extensively studied and discussed; however, the microscopic forms of the genus, especially those from running waters, are poorly known and likely represented by many more species than currently described. Nostoc isolates from biofilms of two Spanish calcareous rivers were characterized comparing the morphology and life cycle in two culture media with different levels of nutrients and also comparing the 16S rRNA gene sequences. The results showed that trichome shape and cellular dimensions varied considerably depending on the culture media used, whereas the characteristics expressed in the course of the life cycle remained stable for each strain independent of the culture conditions. Molecular phylogenetic analysis confirmed the distinction between the studied strains established on morphological grounds. A balanced approach to the evaluation of diversity of Nostoc in the service of autecological studies requires both genotypic information and the evaluation of stable traits. The results of this study show that 16S rRNA gene sequence similarity serves as an important criterion for characterizing Nostoc strains and is consistent with stable attributes, such as the life cycle.