STUDIES ON OLIGOSACCHARIDE SYNTHESIS BY 5 SPECIES OF HELMINTHOSPORIUM

The effect of L-sorbose on the transglycosidase activity of five species of llelminthosporiuin (H. specifcrum [Bain.] Nicot, H. rostratum Drechs., H. hawaiiense Bougn., H. nodulosum Berk ex Curt, and H.hatodes [Drechs.]) during the growth of sucrose and maltose media was studied. Considerable improvement in the yield of mycelial growth was noted on both sucrose and mallose media when they were supplemented with 2 g of sorbose. In maltose medium this enhancement was maintained even when it was supplemented with 5 g of sorbose, whereas in sucrose medium a declinc in dry weight was noted in all species examined, except for II. rostratum. The oligosaccharide synthesis was remarkably depressed when these media were supplemented with 2 g of sorbose in sucrose medium and it was partly inhibited in maltose medium. Pronounced depression in oligosaccharide synthesis was noted in media supplemented with 5 g of sorbose. © 1969 S. Karger AG, Basel.