Development of Entomophaga aulicae protoplasts in synthetic eastern hemlock looper hemolymph

Abstract

The protoplast stages of Entomophaga aulicae grew in a medium based on the amino acid and amine composition of the hemolymph of the eastern hemlock looper, Lambdina fiscellaria fiscellaria. The optimum temperature and pH ranges for spindle-shaped protoplast growth were 15 to 25 °C and 5.5 to 6.5, respectively. Spindle-shaped protoplast development progressed asynchronously through the formation of mesoprotoplasts, elliptical mesoprotoplasts, and rod-shaped and spherical hyphal bodies. The production of these stages was not influenced by either medium pH or osmolality. Conidia were formed on conidiophores arising from spherical hyphal bodies near the surface of the culture medium. Changes in amino acid and amine levels during growth were correlated with the stage of fungal development. The major amino acids utilized during development included L-glutamine, L-asparagine, L-proline, L-leucine, L-isoleucine, L-tyrosine, and the amine O-phosphoethanolamine.Key words: Entomophaga aulicae, Lambdina fiscellaria fiscellaria, protoplasts, hemolymph, ninhydrin-positive compounds.