It has been known that the ability of Shiga toxinproducing Escherichia coli (STEC) to produce Stx2e in culture media plays a role in the diagnosis of edema disease and determination of subunit vaccine candidates in STEC isolates. To examine the efficiency of Stx2e production in several commercial media, a Stx2e-producing strain (KEFS1302) was grown in four different media: ISO-Sensitest broth (ISB), E. coli broth (ECB), trypticase soy broth (TSB), and Mueller Hinton broth (MHB), with or without mitomycin C at 37°C (250 rpm) for 6 h. Toxin production was measured by enzyme-linked immunosorbent assay. In the presence of mitomycin C, ECB was found to be the most suitable medium, reaching a production peak (OD600 = 1.2) at 1 h; Stx2e was mostly produced during the logarithmic phase (within 3 h). On the other hand, toxin production in ISB reached a peak at 3 h after incubation in the absence of mitomycin C. Stx2e was purified by fast protein liquid chromatography (FPLC) using anion-exchange chromatography. The 43 kDa band of Stx2e was confirmed by western blot using the ECB supernatant. Our results showed that ECB and ISB media would be a suitable medium for mass production of Stx2e even if the toxin production is dependent on time.

• Ji-A Jung(Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Ha-Young Kim(Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Ara Jo(Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Jong-wan Kim(Animal Disease Diagnostic Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea)
• Wan-Kyu Lee(College of Veterinary Medicine, Chungbuk National University, Cheongju 28644, Korea)
• Jae-Won Byun(Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Gimcheon 39660, Korea) Corresponding author