Phylogenetic identification of unknown microalgae which isolated from the Caspian Sea

To identify the phylogenetic position of unknown microalgae, which were isolated from the southern coast of the Caspian Sea, all samples were cultured in a specific solid culture medium for microalgae. The grown microalgae strains were transferred to a liquid culture medium for suspension culture. For molecular studies, the suspension was precipitated by adding Iron (III) Chloride solution. The extraction of microalgae genomic DNA was performed by an optimized heat-shock method. Then the polymerase chain reaction was used to partially amplify the genes locus encoding ۱۶s rDNA. Amplification of these regions was performed using ۱۲ set primers designed based on the conserved area. Among these primers, six sets showed proper amplification of target gene regions in the genome. Gene fragments were purified from the gel and ligated into the pTZ۵۷R/T vector by TA cloning technique and amplified in the bacterial strain Dh۵α. Finally, the recombinant plasmids after purification were selected for sequencing. The results were analyzed by Vector NTi ver.۱۱ and blasted at the Genetic Database (NCBI). The phylogenetic tree and similarity matrix with the Maximum Parsimony method for all six gene loci showed that the studied unknown microalgae have the lowest genetic distance with the algal strain Spirulina laxissima.

Keywords:

Cyanobacteria , Ribosomes , Molecular classification , ۱۶s Rdna