Visualization of exocellular lectins in the entomopathogenic fungus Conidiobolus obscurus.

We demonstrated the presence of lectins binding to glucose and N-acetylglucosamine on the surface of Conidiobolus obscurus spores by using glycosylated serum albumins substituted with fluorescent dyes and colloidal gold. The role of these exocellular lectins was examined in relation to the adhesion of the fungal spores to their host insect and the pathogenicity of the fungus.

Lipid level and total fatty acid composition for selected developmental stages of Entomophthora egressa.

The major fatty acids (greater than 10%) of Entomophthora egressa were C16:0 and C18:1 . Minor fatty acids, which varied with the stage of fungal development, included C11:0, C12:0, C13:0, C14:0, C15:0, C16;1, C17:0, C18:0, C18:2, C18:3 C:201, C20:2, C20:3, C20:4, C20:5 and two unidentified unsaturated fatty acids. Differences were observed between the total fatty acid levels of C12:0, C14:0, C17:0, C18:0, and C20:5 and the degree of unsaturation of the fatty acids of 37-h protoplasts grown in modified Grace's medium and a simplified growth medium (SGM). The levels of C12:0, C14:0, C18:1, C20:4, and C20:5 decreased and the levels of C18:0 and C20:2 increased with the formation of spherical hyphal body (shb)initials. With the production of mature shb increased levels of C12:0, C14:0, C15:0, C18:1, C20:4, and C20:5 were detected. During the germination of the shb the levels of C14:0, C16:1, C18;1, and C20:4 increased, whereas C15:0 and C20:5 levels declined. The fatty acid levels, except for C12:0, C13:0, and C20:2, remained constant during the mycelial stage. The degree of fatty acid unsaturation decreased during early stages of development (protoplasts through shb initials). In SGM the degree of fatty acid unsaturation was lowest during the shb initial stage and highest during the shb stage. The total lipid level increased during shb maturation and declined during shb germination.

[Changes in the fatty acid composition of phospholipids during the growth process of microscopic fungi of the family Entomophthoraceae]. / Izmenenie zhirnokislotnogo sostava fosfolipidov v protsesse razvitiia mikroskopicheskikh gribov semeistva Entomophthoraceae.

The fatty acid composition of phospholipids and its changes during growth of two cultures of microscopic fungi belonging to the family Entomophthoraceae have specific peculiarities. Fatty acids in the composition of phospholipids contain from 10 to 20 carbon atoms in the chain; unsaturated fatty acids prevail among them, and constitute about 60% in the phospholipids of Ent. coronata 1932 and about 70% in the phospholipids of Ent. conica 1716. The content of arachidonic acid in the phospholipids of the both cultures is high (up to 17%). The fatty lipids of phospholipids are actively involved in metabolism in the process of the fungal growth, particularly in Ent. coronata 1932 which is characterized by a higher level of metabolism. The total degree of unsaturation of phospholipids changes only slightly during the growth of the two cultures.

[Quantitative changes in the principal cell constituents of Entomophthora virulenta during sporogenesis]. / Variations quantitatives des principaux constituants cellulaires d'Entomophthora virulenta lors de la sporogénèse.

Changes in the relative abundance of cell constituents of Entomophthora virulenta Hall & Dunn were studied during the various differentiation phases leading to the formation of zygospores. The highest total protein (43%) and nucleic acid (5.2% RNA and 0.2% DNA) concentrations were found in the exponential growth phase; these concentrations decreased regularly as the mycelium aged. The amount of lipids was four times larger at the prespore and spore stage (about 25%) than at the exponential mycelial stage. The zygospore contained a very high concentration of chitin (about 17%), three times more than the mycelial concentrations. However, the percentage of polysaccharides without chitin, but including glycogen, was higher in the deceleration phase mycelium (34%) than in the spore (25%). A physiological model of the sexual sporulation of E. virulenta based on these data has been presented.

Study of the long chain bases of sphingomyelin of Entomophthora coronata.

Sphingomyelin was isolated from a strain of Entomophthora coronata, a fungus pathogenic for humans. After hydrolysis, the long chain bases were converted to their dinitrophenyl (N2pH) derivatives and the aldehydes prepared by oxidizing these compounds with periodic acid. The aldehydes were studied by gas chromatography. Twelve different aldehydes were identified, the chain distributiion ranging from C14 to C17. The prominent chains were unsaturated. Straight and branched chains were found. The most abundant parent base which formed 52% of the total aldehyde was a 1,3-dihydroxy-2-aminohexadecene.