Fig. 2
Characterization of Nostoc strain overexpressing the flv3B gene. a Growth curve of Nostoc strains grown in either nitrate-containing medium or nitrate free medium. For each curve, three independent cultures were performed. The growth was assessed during 12 days by measuring the optical density at 750 nm. The standard deviation is indicated by error bars. b Light microscope images of Nostoc strains grown in nitrate-containing medium or nitrate- free medium. For the last conditions, images were acquired 24 h after nitrogen starvation. Heterocytes are indicated by black arrows. c Heterocyte pattern formation in the wild type and the WT/patB-flv3B strain. Strains were grown in BG11 (nitrate-containing medium) to an OD750 of 0.4 and induced to form heterocytes by transfer to BG-110 medium (nitrate-free medium). Vegetative cells and heterocytes were scored microscopically 24 h after nitrogen starvation. The data shown are representative of three independent experiments