African Entomology (2021) 29, 423-434

M.D. Dunn, P.D. Belur and A.P. Malan (2021)
Effect of glucose, agar supplementation and bacterial cell density on the in vitro liquid culture of Steinernema jeffreyense
African Entomology 29 (2), 423-434
Abstract: Entomopathogenic nematodes (EPNs) of the family Steinernematidae are effective biological control agents against important pest insects. The in vitro liquid culture method of mass production is used to produce EPNs of high quantity, quality and with reduced cost by upscaling. The first step in liquid mass production is the use of shake flasks to obtain monoxenic infective juvenile (IJ) inoculum for optimisation purposes, followed by upscaling to a desktop fermenter. This study was undertaken to assess the impact of the addition of agar and glucose to the culture medium, as well as assessing the impact of bacterial cell density inoculum on IJ recovery and yield. Steinernema jeffreyense was cultured in 250 ml Erlenmeyer flasks, with the mutualistic bacterium Xenorhabdus khoisanae. In this study the impact of four different agar and glucose concentrations showed negligible impact on nematode recovery and yield. Different initial bacterial inoculum densities inoculated to the culture medium showed a low inoculum density of 2 % (6 × 10⁶ cells) of the bacteria culture to be the optimal inoculum concentration. A bacterial growth curve for X. khoisanae in tryptic soy broth, showed 40–44 h to be the optimum time for introduction of the initial nematode inoculum into the complex medium.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Antoinette P. Malan

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
rearing/culturing/mass production

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Steinernema jeffreyense (entomopathogen)