Fig. 2

Screening and identification of EpoK-supporting redox partners through the overexpression of putative ferredoxin and ferredoxin reductase genes. a Epothilone A + B and the total production of the parental strain H7029-1, H7029-2 strain expressing epoK, and strains H7029-3 to H7029-10 overexpressing eight other selected ferredoxin genes. b Comparison of the epothilone A + B proportions in the strains overexpressing the putative ferredoxin genes. c Epothilone A + B and the total production of the parental strain H7029-1, the H7029-2 strain expressing epoK, and strains H7029-11 to H7029-16 overexpressing three other putative ferredoxin reductase genes alone or in combination with fdx_0135 or fdx_S4580. d Comparison of the epothilone A + B proportions in the strains overexpressing the putative ferredoxin reductase genes alone or in combination with fdx_0135 or fdx_S4580. e HPLC analysis of the extracts from strains H7029-2, H7029-3, H7029-12, and H7029-15. The changes in the composition of epothilone clearly represented the results of overexpressing ferredoxin and ferredoxin reductase genes. A, epothilone A; B, epothilone B; C, epothilone C; D, epothilone D. All strains above were analysed in triplicate, and the data are presented as the means ± standard deviations of the values from three independent experiments (n = 3)