Assimilation of disaccharides by some fungi causing "leaf spot" diseases

Abstract

Phyllosticta cycadina, P. artocarpina and Pestalotia mangiferoe were isolated from the leaf spot diseases of Cycas revoluta, Artocarpus heterophyllus and Mangifera indica respectively. A detailed study of the assimilation of sucrose, maltose and lactose by these organisms was undertaken. Sucrose and maltose were assimilated through a hydrolytic pathway. Pestalotia mangiferoe utilized both glucose and fructose simultaneously, but the two species of Phyllosticta behaved differently and consumed glucose three days before the other hydrolytic product of sucrose (viz., fructose). Synthesis of an oligosaccharide (maltotriose) was recorded during the assimilation of maltose. Lactose was used through a non-hydrolytic pathway and was found to be a poor source but a mixture of its hydrolytic products supported good growth.