An investigation into the physiological and nutritional requirements of the protoplast stage of the fungus Entomophthora egressa MacLeod and Tyrrell (Phycomycete: Entomophthorales)

Abstract

The physiological and nutritional requirements of the entomogenous phycomycete Entomophthora egressa MacLeod and Tyrrell were determined using the wall-free protoplast stage. -- Based on the uptake of ninhydrin-positive compounds the amino acids in the standard medium, Grace's modified insect tissue culture medium, were simplified to contain the amino acids methionine, asparagine and glutamine. -- The buffer 2-(N-morpholino) ethanesulfonic acid afforded excellent buffering capacity. The protoplasts utilized glucose, were vitamin autotrophic in two different media and required protein for membrane integrity. -- The regeneration patterns were studied throughout the experiments using various liquid and solid media. It was possible to induce mycelial and hyphal body development in the two simplified liquid media. -- Biochemical analysis of the fungal host, Lambdina fiscellaria fiscellaria (Guenee) in terms of haemolymph amino acids resulted in the development of a medium superior to the standard medium. Fatty acid analysis and total lipid production for various stages of the fungal host and protoplasts were determined.