Enhanced hyphal body production byEntomophaga aulicaeprotoplasts in the presence of a neutral and a positively charged surface under mass fermentation conditions

摘要

The effects of two disks, one with a net neutral charge (Mylar) and one with a positive charge (polypropylene), on hyphal body production from protoplasts of the fungusEntomophaga aulicaeunder mass fermentation conditions were determined. The results were compared with those obtained with a vessel lacking a disk (control). The presence of either disk greatly enhanced hyphal body production, especially by day 4 of incubation. A maximum level of 94.1 hyphal body production was achieved using the disks as compared to a maximum level of 42 under control conditions. With the exception of aspartic acid, which was produced under control conditions and not utilized when the disks were present, the amino acids were removed from the medium earlier and (or) more completely in the presence of the disks. Glucose utilization and oxygen consumption were greater in the presence of the disks. The utilization of fermentation vessel configurations employing neutral or positively charged disks (surfaces) offers a method for greatly enhancing hyphal body production for biocontrol of the larval stages of forest defoliators.Key words:Entomophaga aulicae, hyphal body production, biological control, mass fermentation, neutral and positively charged surfaces.