Liquid-culture production of blastospores of the bioinsecticidal fungus Paecilomyces fumosoroseus using portable fermentation equipment

Abstract

The production of fungal spores using on-site, non-sterile, portable fermentation equipment is technically constrained. Very little information is available on the production requirements, such as medium concentration, inoculum stabilization, required fermentation times, and maintenance of axenic growth. In this study, we developed a two-part, liquid concentrate of the production medium that remains stable and soluble at room temperature. We also examined inoculum stability and showed that freeze- or air-dried blastospore preparations were stable for 7 days after rehydration when stored at 4 degrees C. The use of a low-pH (pH 4), relatively rich complex medium provided a growth environment deleterious to bacterial growth yet conducive to rapid sporulation by Paecilomyces fumosoroseus. High concentrations of blastospores (7.9 x 10(8)/ml) of P. fumosoroseus were produced in a 40-h fermentation with very low levels of bacterial contamination when the fermentor was charged with a blastospore production medium with a starting pH of 4 and inoculated with blastospore concentrations greater than 1 x 10(6) spores/ml. These studies demonstrate that the use of disinfected, portable fermentation equipment has potential for on-site production of high concentrations of blastospores of the bioinsecticidal fungus P. fumosoroseus.

An oil‐based formulation of Isaria fumosorosea blastospores for management of greenhouse whitefly Trialeurodes vaporariorum (Homoptera: Aleyrodidae)

“…The cost of their production is high because of the risk of contamination and the long culturing time required (up to 4 weeks of growth). Moreover, for solid culturing, large spaces with appropriate facilities and skilled technicians are needed for careful handling of culture bags or trays for suitable aeration . In liquid culturing, the fungi produce blastospores, which are developed from hyphae, and their production is completed in 3–4 days (depending on the culture medium).…”

“…Moreover, for solid culturing, large spaces with appropriate facilities and skilled technicians are needed for careful handling of culture bags or trays for suitable aeration. 6 In liquid culturing, the fungi produce blastospores, which are developed from hyphae, and their production is completed in 3-4 days (depending on the culture medium). This short production time reduces the risk of contamination and the cost of production.…”

Two strains ofPseudomonas fluorescensbacteria differentially affect survivorship of waxworm (Galleria mellonella) larvae exposed to an arthropod fungal pathogen,Beauveria bassiana

“…Jackson, Payne and Odelson (2004) observed that low levels of bacterial contamination in massproduced conidia of another entomopathogenic fungus Isaria (formerly Paecilomyces) fumosoroseus did not cause significant problems. However, as Jenkins and Grzywacz (2000) argued, higher levels of microbial contamination can interfere with, among other things, biopesticide efficacy.…”

Biowarfare Lessons, Emerging Biosecurity Issues, and Ways to Monitor Dual-Use Biotechnology Trends in the Future

“…These findings suggest that it may be cost-effective and feasible to use non-sterile equipment in certain botechnology applications in the future. 31 Another illustration of how mobile equipment has become occurred in South Africa in 2003. In 2003, a visiting Danish researcher and two South Africans surprised much of the scientific establishment, the government, and the public with their announcement that they had "cloned a cow" at a relative remote research station using a new, handmade cloning method that used a hand-crancked generator for power.…”