Similarity analysis of <i>Spirulina/Arthrospira</i> strains on the basis of phycocyanin operon locus (cpcB-IGS-cpcA) and 16S rRNA gene sequences

Abstract

<i>Spirulina/Arthrospira</i> is a species of cyanobacteria used in health foods, animal feed, food additives and fine chemicals. The present study conducted a comparison of the 16S rRNA and cpcBA-intergenic spacer (cpcBA-IGS) gene sequences in <i>Spirulina/Arthrospira</i> strains from culture collection of CCUBGA, IARI, New Delhi. All the strains of <i>Spirulina</i> used in this study had shown nearly 99% similarity amongst them. About fifty sequences (cpcBA-IGS) of <i>Spirulin</i> a strains taken from NCBI with ten from the present strains of <i>Spirulina</i>, a neighbour-joing (NJ) tree was constructed with the help of MEGA 5.0. The tree showed 99% similarity. All the sequences were put to Multiple Sequence Alignment with the help of T-Coffee (version 7.38) and BioEdit (version 7.38) software. Similarity studies undertaken based upon 16S rRNA and cpcBA-IGS genes sequence analysis indicated similarity coefficient of 0.84.<i> S. platensis</i> and <i>Arthrospira</i> sp. showed 100 percent similarity. Therefore, the current study supports some previous conclusions based on 16S rRNA gene and cpcBA-IGS sequences, which found that <i>Arthrospira</i> taxa are monophyletic. However, compared to 16S rRNA sequences, cpcBA-IGS sequences might be better suited to resolve close relationships and interspecies variability.