Purification of Levan Fructotransferase fromArthvobacter nicotinovoramGS-9 and Production of DFA IV from Levan by the Enzyme

A bacterial strain, GS-9, isolated from soil as a levan-degrading microorganism produced an extracellular enzyme that converted levan into DFA IV. This strain was identified as Arthrobacter nicotinovorvans. The DFA IV-producing enzyme was specifically induced by levan. The enzyme was purified 60-fold from culture supernatant to give a single band on SDS-PAGE. The molecular weight of this enzyme was 52,000 by SDS-PAGE and a monomer by gel filtration. The enzyme gave DFA IV as a main product (> 75%), and fructose, levanbiose, and two unidentified oligosaccharides as minor products, and was identified as a novel levan fructotransferase.