Optimisation of a cyanobacterial culture used for production of isotopes-labelled recombinant proteins

A culture of Spirulina platensis was optimised for the preparation of an is otopes-labelled medium that can be used for cultivation of E. coli. Optimis ed conditions include 0.625 g [N-13]-NaNO3/l and 5.6 g [C-13]-NaHCO3/l, and maintenance of a basic pH. The medium produced from the hydrolysed cyanoba cterial biomass supported the growth of E. coli with a doubling time and bi omass comparable to those obtained with the rich medium LB. This procedure allowed a reduction of the costs of isotope labelling of recombinant protei ns by a factor of about 3.