Role of environmental factors in phase shift of Xenorhabdus sp. SGchamp: An endo-symbionts of Steinernema thermophilum.

Xenorhabdus sp. SGchamp, mutualistically associated with insect-pathogenic nematodes of the families Steinernematidae are known to produce two colony forms, designated as primary and secondary phase. The primary form is better in its ability to provide nutrients for the nematodes in insects as well as for entomopathogenicity of nematode. The mechanism of phase variation is still not clear. Therefore, in present study, the effect of various environmental factors like temperature, pH and aeration conditions on phase reversion of the symbiotic bacteria associated with Steinernema thermophilum from Uttarakhand, India is being investigated. The results indicated that aeration and osmolarity played an important role in phase reversion.