Liquid culture of the entomopathogenic nematode-bacterium-complex Heterorhabditis megidis/Photorhabdus luminescens
Authors: Ehlers R-U.; Lunau S.; Krasomil-Osterfeld K.; Osterfeld K.H.
Source: BioControl, Volume 43, Number 1, 1998 , pp. 77-86(10)
A process technology for production of the entomopathogenic biocontrol nematode-bacterium complex Heterorhabditis megidis/Photorhabdus luminescens in monoxenic liquid culture in laboratory scale bioreactors is described. Dauer juvenile yields varied between 21 and 68 million dauer juveniles/l medium. The maximum density was reached at 13 to 25 days after inoculation of P. luminescens. The reason for the high variability in yield was identified. After the 24-h bacterial preculture the bioreactor is inoculated with nematode dauer juveniles which develop to self-fertilizing hermaphrodites. The exit from enduring dauer stages (recovery) was between 18 and 90% of the inoculum density. Low dauer juvenile recovery resulted in the development of two-generations within 20 to 25 days. In contrast, high dauer juvenile recovery led to a one-generation process terminated within 15 days. Factors influencing dauer recovery are still unknown.
Document Type: Regular paper
Publication date: 1998-01-01