Please use this identifier to cite or link to this item: http://hdl.handle.net/10603/8801
Title: Identification and molecular characterization of symbiotic bacteria (Xenorhabdus sp.) associated with indigenous entomopathogenic nematode (Steinernema sp.)
Researcher: Sushil Kumar
Guide(s): Yadav, Anita
Ganguli, Sudarshan
Keywords: Bio Technology
Entomopathogenic nematodes
Steinernematids
symbiotic bacteria
Heterorhabditids
Upload Date: 15-May-2013
University: Kurukshetra University
Completed Date: 2011
Abstract: Members of the genus Xenorhabdus and Photorhabdus are symbiotically associated with the infective juveniles (IJs) of the entomopathogenic nematodes belonging to the genera Steinernema and Heterorhabditis. These bacteria are instrumental in killing the insects by causing septicemia within 24 to 48 hours, and also providing nutrition for the nematodes. These nematodes along with their bacteria are soil dwelling lethal parasites of insects, which are being used as effective biopesticides for promoting organic farming and for managing several insect pests of crops as well as some household pests. An investigation was undertaken with the objectives to (i) isolate the symbiotic bacterium associated with indigenous Entomopathogenic nematode species, (ii) characterize them based on morphological, biological, biochemical and molecular parameters and (iii) establish the species identity of the bacterium isolated from Entomopathogenic nematodes. newlineExtensive surveys were carried out throughout Meghalaya and Kerala, the two states of India and collected 86 soil samples. Soil samples were baited with Galleria mellonella for isolating entomopathogenic nematodes (EPNs). Bacteria associated with EPNs were isolated from the hemolymph of insect on NBTA medium. The symbiotic bacterium associated with S. meghalayensis and Steinernema sp strain IARI-EPN-SGkr, were characterized and proposed as new species of the genus Xenorhabdus, i.e. X . meghalayensis sp. nov. and X. keralensis sp. nov. on the basis of 16s rRNA gene sequence comparison, RFLPs, cultural, biochemical and morphological characteristics.The nearest phylogenetic relatives of bacterium X. meghalayensis were X. kozodoii (97%), X. stockiae (95%) and X. hominickii (95%) based on similarity in 16s rDNA sequence. It is different from other known species of the genus in their ability to cause distinct starch hydrolysis, being positive for Tween 80, Arabinose and for N-Acetyl-D-Glucosamine and D-Gluconic Acid utilization.
Pagination: 99p.
URI: http://hdl.handle.net/10603/8801
Appears in Departments:Department of Bio-Technology

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01_title.pdfAttached File99.59 kBAdobe PDFView/Open
02_declaration.pdf117.9 kBAdobe PDFView/Open
03_certificate.pdf117.94 kBAdobe PDFView/Open
04_acknowledgements.pdf89.98 kBAdobe PDFView/Open
05_abstract.pdf415.03 kBAdobe PDFView/Open
06_abstract in english.pdf90.8 kBAdobe PDFView/Open
07_contents.pdf192.38 kBAdobe PDFView/Open
08_list of plates.pdf134.36 kBAdobe PDFView/Open
09_list of figures.pdf100.5 kBAdobe PDFView/Open
10_list of tables.pdf92.69 kBAdobe PDFView/Open
11_abbreviations.pdf113.74 kBAdobe PDFView/Open
12_list of publications.pdf81.75 kBAdobe PDFView/Open
13_chapter 1.pdf142.08 kBAdobe PDFView/Open
14_chapter 2.pdf382.8 kBAdobe PDFView/Open
15_chapter 3.pdf221.13 kBAdobe PDFView/Open
16_chapter 4.pdf233.47 kBAdobe PDFView/Open
17_chapter 5.pdf139.9 kBAdobe PDFView/Open
18_references.pdf256.08 kBAdobe PDFView/Open
19_appendix.pdf112.64 kBAdobe PDFView/Open
20_figures.pdf2.33 MBAdobe PDFView/Open
21_tables.pdf313.25 kBAdobe PDFView/Open


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