Fig. 1

Butenyl-spinosyn production analysis. a The HPLC profiles of the wild-type and mutant strains. The detection wavelength was set at 250 nm during the analysis, and the chromatographic peak of butenyl-spinosyn appeared at 13.1 min. b Butenyl-spinosyn was detected for 10 days in the wild-type and mutant strains. The maximum production of butenyl-spinosyn in S. pogona was 424.3 mAU*s, and that of S. pogona-Sp1418 was 1382.9 mAU*s, while butenyl-spinosyn was hardly detected in S. pogona-Δsp1418 under the same conditions. The maximum concentration of butenyl-spinosyn produced by S. pogona-Sp1418 increased by 225.9% as compared to that produced by wild type. *, **and *** indicated P < 0.05, P < 0.01 and P < 0.005, respectively, compared to S. pogona under the same conditions. Error bars indicated standard errors of results from n = 3 replicates