Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Large-scale production of viral biopesticides

Chemical crop protecting agents may impose considerable environmental stress and induce resistance in insects. Therefore, bioinsecticides form a challenging alternative. Especially baculoviruses are of interest, since they are highly specific for the target pest, and no resistance has been reported so far. The project developed an insect-cell-culture process on an industrial scale for the production of a viral biopesticide. Traditionally, baculoviruses are produced in insect larvae. This process is laborious and difficult to scale-up. Moreover, insects are easily contaminated. Modern cell-culture technology facilitates the growth of insect cells in suspension in bioreactors. Successively, those cells may be infected with the extracellular form of the baculovirus, after which the cells will produce the occluded form of the virus (Polyhedra Inclusion Bodies, PlBs) found in nature

New SeNPV and HaNPV strains were isolated from the Iberian Peninsula, and the NPV isolates were characterized. Insecticidal activity of the isolates were determined but no significant differences were found. Two new cell lines, now established, emerged from Se, with optimized growth in serum-free suspension cultures.

A mathematical model describing the behaviour of insects, formulations and spray applications in the field was constructed and in vivo baculovirus bioassay methods and an in vitro test method was developed. The method was used to quantify baculovirus temperature and simulated sunlight inactivation. The ultraviolet assay system allowed the testing of potential UV protectants and the protective effect of propyl gallate was demonstrated. It was shown that there was no difference in inherent infectivity of in vitro and in vivo produced HaSNPV and AcMNPV. Furthermore the extraction and purification of in vitro produced baculovirus was shown to be much easier and with a much higher efficiency compared to in vivo produced virus. The results of a field trial carried out on alfalfa showed no differences in insecticidal activity between in vitro and in vivo produced SeMNPV.

Reported by

Wageningen Agricultural University
6700 EV Wageningen