Illustration of the different lsc genes and fusion constructs. (a) Levan formation ability of the proteins encoded by the fusion constructs in levan negative mutant PG4180.M6. The cells were grown on mannitol-glutamate agar medium containing 5% sucrose at 18°C to check for levan formation (indicated by the dome-shaped glossy slime) around the colony. LscB, LscBUpNA and LscBUpA showed levan formation. (b) Schematic representation of the DNA fusion products. The dashed line and dashed arrow represents lscB while the solid line and solid arrow represents lscA.