Synthesis of pullulan by acetone-dried cells and cell-free enzyme from pullularia pullulans, and the participation of lipid intermediate

It was demonstrated that the polysaccharide, pull ulan, was synthesized from sucrose by acetone-dried cells of Pulfularia pulfulans or from UDPG by cell-free enzyme preparations prepared from the organism. The pullulan formed was estimated by precipitation with ethanol, and determining maltotriose produced after treating the precipitate with Aerobacter isoamylase (pullulanase). Acetone cells (5 g) shaken with 200 ml of 10% sucrose produced over 250 mg of pullulan per 100 ml after 90 hr at 3ºC and pH 6.0. Cell-free enzyme produced pullulan from UDPG in the presence of ATP. ATP was essential for the biosynthesis, and ADPG could not replace for UDPG. In addition, it was observed that a lipid containing glucose residue was formed during. the reaction. The nature of this glucolipid was examined, and possible participation of a lipid intermediate was assumed in the pullulan biosynthesis.