Phylogenetic analysis of Arthrospira strains from Ordos based on 16S rRNA

To study the growth rate of different Arthrospira strains, three species of Arthrospira from Ordos alkaline lake, labeled as sp.DD, sp.ER, sp.FB, one species of Arthrospira from Hasu Sea in Hohhot, labeled as sp.HS, another purified strain labeled as sp.QD donated by the Ocean University of China had been collected. The first four need to be further isolated and purified in culture. The growth curves of all strains were plotted. Subsequently, 16S rRNA sequences were amplified and sequenced in an attempt to study taxonomic relationships. The results showed that the growth rate was increased in the first 9 days, and sp.DD had the highest growth rate. Analysis of the sequencing results revealed that sp.HS had 99.79% homology with Arthrospira platensis strain Sp-2, sp.DD had 99.69% homology with Arthrospira platensis FACHB834, sp.QD had 99.54% homology with Arthrospira platensis F3S, sp.ER had 99.79% homology with Arthrospira erdosensis ‘Inner Mongolia’, sp.FB had 99.74% homology with Arthrospira erdosensis ‘Inner Mongolia’. Phylogenetic analysis indicated that sp.HS was closely related to Arthrospira platensis strain Sp-2; sp.DD and sp.QD had a close genetic relationship; sp.ER and sp.FB had a close genetic relationship. In conclusion, these findings provide a theoretical basis for the further development and reproduction of dominant algae species in Inner Mongolia through biological analysis of Arthrospira.