Cloning and Prokaryotic Expression of C-Phycocyanin Gene from Nostoc flagelliforme Isolation and Purification of C-phycocyanin from Nostoc flagelliforme Study on Mass Production of Phycobilins from PC Rich Strain of Spirulina platensis Biosynthesis of a Fluorescent Cyanobacterial C-phycocyanin Holo-α Subunit in Escherichia coli