Fig. 2

Strength of promoter candidates measured by a GFP reporter. A Construction of a GFP expression plasmid under the control of a predicted promoter for integration into a Methylomonas sp. DH-1 chromosome. B Promoter strength measurement in Methylomonas sp. DH-1 by flow cytometry. Promoters showed up to 410-fold differences in GFP expression. The strength was normalized by that of the lac promoter (100%). As the y-axis is drawn at log scale, five promoter candidates that showed no detectable fluorescence were excluded from the graph. Data indicate mean ± SEM (n = 3)