Effect of nutritional factors on the culture of Nostoc sp. as a source of phycobiliproteins

Summary The effect of nutritional factors in a new culture medium (BW₃) is described for the cyanobacterium Nostoc sp. The growth of Nostoc sp. was higher in BW₃ than in control media currently used for cyanobacteria. With medium BW₃ the content of the pigment c-phycocyanin depended on the culture conditions employed, particularly the nature of the nitrogen and carbon sources. Higher amounts of c-phycocyanin amounting to 20.1% on a dry-weight basis were accumulated when both sources were supplied in the gas phase of the culture. The phycobiliproteins of Nostoc sp. were resolved into two components: c-phycocyanin (_max = 614 nm) and allophycocyanin (_max = 652 nm). The phycobiliprotein composition was 30% allophycocyanin and 70% c-phycocyanin. The culture of Nostoc sp. in BW₃ medium seems promising as a source of biomass for the production of natural dyes.