Taxonomic Identification of Bacteria, Associated with Bulgarian Populations of Entomopathogenic Nematodes from Genus Steinernema (Rhabditida, Steinernematidae) II

ABSTRACT

The entomopathogenic nematode from the genera Steinernema and Heterorhabditis are symbiotically associated with bacteria from the genera Xenorhabdus and Photorhabdus. The bacteria belong to the family Enterobacteriaceae; pathogenic when injected into the hemocoel of Galleria mellonella (Lepidopthera) larvae. All Xenorhabdus and Photorhabdus isolates have been shown to produce two forms when cultured in vitro. These colony forms indicate two phases that differ in their morphological and biochemical characteristics. Each nematode species has a specific association with one species of bacterium. Xenorhabdus or Photorhabdus species may be associated with more than one species (1, 2). Entomopathogenic nematodes represent one important part of the spectrum of biocontrol agents. They are used to control insect pests in high-value crops and potentially they could be used in integrated pest management, organic farming and sustainable agriculture systems to control soil-borne insect pests. During our study we found bacteria belonging not only to the family Enterobacteriaceae. The results of an investigation on taxonomic identification of bacteria, isolated from three different entomopathogenic populations are presented in this paper.