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Fig. 3 | Microbial Cell Factories

Fig. 3

From: Systematic identification of endogenous strong constitutive promoters from the diazotrophic rhizosphere bacterium Pseudomonas stutzeri DSM4166 to improve its nitrogenase activity

Fig. 3

Enhanced nitrogenase activity by overexpressing nifA using endogenous strong constitutive promoters in DSM4166. (A) The nitrogenase activity of DSM4166 and nifA overexpression strains cultivated in the nitrogen-free medium K at 1% oxygen determined by the acetylene reduction method. (B) The concentration of extracellular ammonium produced by DSM4166 and nifA overexpression strains. (C) The transcriptional level of selected 25 nif genes in the P12445-nifA overexpression strain relative to DSM4166 cultivated in the same condition as A. Error bars indicate the standard deviations of three replicates (n = 3). The P-value cutoff for all the plots is 0.05. * P < 0.05, ** P < 0.01, and *** P < 0.001. ns, not significant. One-way ANOVA test with Tukey Pairwise comparisons was used to compute statistical significance

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