Molecular insight into the metabolic activities of a protein-rich micro alga, Arthrospira platensis by de novo transcriptome analysis.

To gain genetic insights into the protein-rich microalga, the transcriptome of Arthrospira platensis was sequenced using Illumina technology and de novo assembly was carried out. A total of 6023 transcripts were present in the transcriptome among which 4616 transcripts were annotated with specific functions. Gene ontology analysis revealed that the genes are mainly involved in three major functions such as biological (16.19%), cellular (41.47%) and molecular (42.34%) processes. Pathway analysis indicated that majority of genes are involved in amino acid biosynthesis and metabolism which is depicting the protein-rich nature of spirulina. Other major pathways involved are carbohydrate metabolism, lipid metabolism, metabolism of co-factors and vitamins, antioxidant mechanism and metabolism of terpenoids and polyketides. qRT-PCR analysis was performed to confirm the potential antioxidant role of five candidate genes of spirulina in protecting the cells from oxidative stress induced by hydrogen peroxide. Moreover, these results indicated that spirulina is rich in biological resources which could be efficiently used for multiple applications such as carbon dioxide utilization, nitrogen fixation and biofuel production.