The plasmids carrying CDF-MKI4 and pET28a-MicA were transformed into E. coli BL21 Gold (DE3). The transformed strains were cultured in lysogeny broth (LB) containing kanamycin (50 mg/L) and streptomycin (50 mg/L). After overnight growth, the cultures were inoculated into 90 × 1 L of fresh LB medium. IPTG (0.5 mM) and isoprenol (1.0 mM) were added to the cultures when OD600 reached 1.5 and further incubated at 28 °C and 250 rpm for an additional 18 hours. After centrifuging the cultures at 4000 rpm for 15 min, the resulting pellet was extracted with methanol (MeOH). Next, the organic extract underwent partitioning with petroleum ether (PE).