ISOLATION AND CHARACTERIZATION OF SYMBIOTIC BACTERIUM ENTEROBACTER HORMAECHEI FROM ENTOMOPATHOGENIC NEMATODE AND INSECTICIDAL ACTIVITY OF BACTERIAL ISOLATE AND ITS SECONDARY METABOLITE ON SPODOPTERA LITURA LARVAE

Author (s) : Dr.V.K.EVANJALENE and Dr.S.POONGODI

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Abstract :
Entomopathogenic nematodes are potential agent for control the agriculture insect pests. Entomopathogenic nematodes are associated with symbiotic bacterium, which cause virulence in insects. In this study Panagrolaimus spp nematode was isolated from soil and symbiotic bacteria isolated from nematode infecting Spodoptera litura. Based on biochemical, physiological and molecular characterization the isolated symbiotic bacterium was identified as belonging to from Enterobactericea family. Phylogenetic analysis of 16S rDNA sequence of symbiotic bacteria is Enterobacter hormaechei. Furthermore, isolated entomopathogenic nematodes were infected to S. litura larvae fed on different diet (artificial diet + Zn, 3P+1C and 1P+3c) with ratio of protein, carbohydrate and zinc (50mg/kg of diet) in diet. 48hrs infection of entomopathogenic nematode shows high mortality to S. litura grow on artificial diet comprise with Zn and 3P+1C diet. Enterobacter hormaechei and its secondary metabolites treated to S. litura in different concentration (10 -4 , 10 -5 and 10 -6 ). Symbiotic bacteria and secondary metabolites cause high mortality to S. litura maintained in all diet groups. Mortality rate depend on concentration of Enterobacter hormaechei and secondary metabolites. Additionally ethyl acetate extract of Enterobacter hormaechei was analyzed by FT-IR and GC-MS, which shows the presence of alkanes, carboxylic acids, aldehydes, misc, amines, alkylhalides and alkynes functional groups, while benzenepropanoic acid, dibutyl phthalate and 1,2- benzenedicarboxylic acids compounds were observed by GC MS analysis. HPLC spectrum analysis also showed peaks at 3-8mins of retention time. This study shows that virulence of symbiotic bacteria Enterobacter hormaechei and its secondary metabolites can be utilized in pest control programs in agriculture.

Keywords : Enterobacter hormaechei, Nematodes, Panagrolaimus sp, FT-IR, GC-MS, HPLC, symbiotic.

Conference Date : 17/09/2021

Pages : 77

Paper ID : IESMDT75