Plant parasitic nematodes are parasitized and preyed by a variety of soil organisms which includes predatory nematodes, fungi, bacteria, viruses, protozoans, turbellarians, tardigrades, mites and other microarthropods. One such spore forming and an obligate parasite is Pasteuria penetrans. The major limitation in the use of Pasteuriaspp. is their inability to grow in the absence of host nematodes. In vivo systems although proven are unlikely to be adopted for large scale application in most farming systems. Attempts were made to culture the organism in in vitro. Among the symbiotic bacteria used for mass production co-culturing with Enterobacter proved to be successful in culturing this obligate organism in a specially developed medium for mass multiplication.