Inactive corrinoid-compound significantly decreases in Spirulina platensis grown in a cobalt-deficient medium.

Spirulina platensis NIES-39 was grown under open culture system in the presence or absence of CoSO(4) (12 microg/L) and/or vitamin B(12) (10 microg/L) to confirm whether CoSO(4) and/or vitamin B(12) stimulate or are essential for growth of the algal cells and for accumulation of vitamin B(12). The addition of CoSO(4) and/or vitamin B(12) could not affect both cell growth and cell yield of the alga. The amount of corrinoid-compound was increased significantly by the addition of CoSO(4) but not by vitamin B(12). A C18 reversed-phase HPLC pattern of the Spirulina corrinoid-compound increased by the addition of CoSO(4) was identical to that of authentic pseudovitamin B(12), which is inactive for human. These results indicate that the algal cells grown in the absence of CoSO(4) are suitable for use of human health foods because the inactive corrinoid-compound can be reduced significantly.