Glucofructosan biosynthesis in Fusarium oxysporum

Low MW glucofructosans have been detected in the medium of Fusarium oxysporum. A 53-fold purification of fructosyl transferase has been achieved by ethanol precipitation, DEAE-cellulose and Sephadex G-100 column chromatography. Maximum fructosyl transferase activity coincided with maximum glucofructosan concentration in the medium. Invertase showed greatest activity in the later stages of growth when glucofructosans were absent. Fructosyl transferase and invertase have been separated by DEAE-cellulose column chromatography. On the basis of kinetic studies and effect of nucleotides on fructosyl transferase in the presence and absence of MgCl₂, a two site active centre linked through a nucleotide bridge is proposed. Fructosyl transferase and invertase are highly phosphorylated.