Influence of Physical Factors and Selected Media on the Growth of Entomophthora Egressa Protoplasts Isolated from Spruce Budworm Larvae

ABSTRACT

The effects of selected physical factors and media on the growth of protoplasts of Entomophthora egresso were determined. The optimum temperature was 20 C. Shaken protoplast cultures grew faster than stationary cultures. Protoplast growth was optimal in the medium containing 10 mm 2-n-(morpholino)ethane sulfonic acid as a buffer at pH 6.2. Based on the maximum level of protoplasts in spindle-form and the shortest generation time, the optimum osmolality was 350 mOsm/kg. Charged and neutral Sephadex resin beads did not influence protoplast growth rates but DEAE-Sephadex and Sephadex G-200 favored mycelial development. Reducing the amino acid and carbohydrate complexity of the growth medium increased the generation time of the protoplasts. The data permit the maximum production of protoplasts to facilitate additional physiological studies.

Key Words:

• Entomophthora egresso
• temperature
• pH
• osmolality
• entomopathogen