Fig. 1From: Overproduction of the Flv3B flavodiiron, enhances the photobiological hydrogen production by the nitrogen-fixing cyanobacterium Nostoc PCC 7120Flv3B overproduction analysis. a–c Quantitative RT-PCR analysis of flv3B (a, c) and patB (b, d) gene transcription. RNA were collected from the wild type (a, b) or the WT/patB-flv3B (c) strain at four different times (7, 18, 24 and 48 h) after the onset of nitrogen depletion. Each sample was measured in triplicate and the standard deviation is indicated by error bars. Values were normalized to the rnpB transcript, relatively to the value obtained for the wild type strain, which was set to 1. d Immunoblot analysis of the amount of Flv3B protein (upper panel) in the wild type and WT/patB-flv3B strains, carried out using antibodies produced against FlvB from Chlamydomonas reinhardtii [18]. Immunoanalysis of RbcL protein amount was carried out as a loading control (lower panel). The condition (+ Nitrate) stands for cultures performed in nitrate-containing medium, and the condition (− Nitrate) indicates cultures grown in nitrate-free mediumBack to article page