The Influence of Xenorhabdus nematophilus (Enterobacteriaceae) on the Propagation of Entomopathogenic Nematodes Steinernema carpocapsae (Weiser) in Liquid Culture

Abstract

The influence of symbiotic bacterium Xenorhabdus nematophilus (Enterobacteriaceae) on the propagation of entomopathogenic nematode Steinernema carpocapsae in liquid medium conducted in the laboratory of Entomology and Zoology division, Dept. of Agriculture was carried out in the following issues:
1. Culturing X. nematophilus and s. carpocapsae together in 4 different conditions (treatmens) and each has 5 replications (CRD) as follows:
1.1) cultruing bacteria in liquid culture 24 hours long before nematode inoculation,
1.2) inoculation of bacteria and nematode in liquid culture at the same time,
1.3) bacterial cells were cultured 24 hours long and filtered before nematode inoculation and
1.4) culturing nematode without bacterial inoculum.
Thirty ml liquid medium contained in 125 ml conical flask was autoclaved at 121 C. for 30 min. Each flask was then inoculated with 10 bacterial cells and 30,000 infective juveniles of nematode. The result showed that the first treatment gave the highest yield (166,139 nematodes/ml) and is significantly different (P=0.05) from other methods.
2. Study on the effect of inoculum sizes on yield of nematode in liqued medium. Four inoculum sizes of bacteria 3x10 , 3x10 3x10 and 3x10 cell/ml. were used. The result showed that the yield of infective juveniles of nematode/ml increased with inoculum sizes of bacteria.