Divergence in three newly identified Arthrospira species from Mexico.

Arthrospira (Spirulina) is a microalgae that has a unique set of biological characteristics which are very useful for a broad range of applications. Based on its worldwide requirements, this investigation was conducted to collect, isolate and identify the local Arthrospira strains in the central and western part of Mexico. We have successfully collected, isolated and identified (morphologically as well as molecularly) three Arthrospira strains from different regions in Mexico. Morphological studies were conducted by analyzing the size and shape of the helix, the spiral pattern, cell length and width with the help of light microscopy and for molecular analysis, the 16S rRNA and internally transcribed spacer (ITS, 16S-23 rRNA) gene partial sequence were used followed by phylogenetic analysis. The three species were completely different in their filament size and width whereas their ITS sequences were the same in size and more than 87 % similar in nucleotide sequence. The resulted morphological and phylogenetic analysis concluded that the three stains were identified as Arthrospira platensis. Inspite of their morphological variations and differences they were grouped genetically into one cluster along with the A. platensis of reported strains of Gene Bank database (NCBI). One of the isolated strains NPS-0, is probably the biggest Arthrospira strains ever reported and can be suitable for industrial scale biomass and protein production.