Cloning, nucleotide sequence, expression in escherichia coli of levansucrase genes from the plant pathogens pseudomonas syringae pv. glycinea and P. syringae pv. phaseolicola - Boch, Jens.; Hettwer, Ursula.; Jaeckel, Frank R.; Meyer, Manfred.; Rudolph, Klaus.; Ullrich, Matthias S.