Isolation and Cloning of Phycocyanin Alpha Subunit Gene and its Production in E.coli Expression System

Phycocyanin is a blue pigment in two eukaryote algal genera and in cyanobacteria as Spirulina. This pigment has various biology activities and are utilised in a number of applications in foods, cosmetics and pharmaceuticals. A lot advantage of phycocyanin studied by many researchers but the scale-up of these methods is difficult and expensive while production of recombinant phycocyanin is more convenience and inexpensive to scale up protein desire. The purpose of this study was to isolation and cloning of phycocyanin alpha subunit gene in expression vector and production of recombinant protein in E.coli to provide industrial production of phycocyanin. The genomic DNA of Spirulina platensis was prepared and used for PCR as template. phycocyanin alpha subunit gene amplified by designed specialize primers was cloned in a pET43.1a expression vector, under the control of T7 promoter using NdeI and NotI restriction enzymes. The cloning of phycocyanin alpha subunit gene is confirmed by colony PCR, digestion and DNA sequencing. The constructs were transformed into E.coli strain BL21 (DE3). Expression of phycocyanin alpha subunit gene was examined by 12.5 % SDS-PAGE analysis at 8 hrs after induction by IPTG. The SDS-PAGE analysis showed that alpha subunit phycocyanin was produced in E.coli expression system. Our study provided the production of recombinant phycocyanin. Also overexpression of the synthetic alpha subunit phycocyanin in a bacterial system (E.coli BL-21) showed that E.coli can be used to produce this desire protein in large quantity.