Detection of levansucrase. (a) Western blot analysis: 10 μg of total proteins were separated by 10% SDS-PAGE, transferred onto PVDF membrane, hybridized with anti-Lsc antiserum and detected using BCIP/NBT. The dark bands (arrow) correspond to Lsc and the corresponding fusion proteins. (b) Zymogram: 100 μg of total proteins were separated by 10% native-PAGE and incubated in 5% sucrose solution overnight. The white bands indicate formation of levan after utilization of sucrose by Lsc and the fusion proteins.