scholarly journals The insecticidal activity of an entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens against Periplaneta and Blattella cockroaches

2020 ◽  
Vol 50 (2) ◽  
pp. 27-33
Author(s):  
Takahiro Hamaguchi ◽  
Daiki Sawanomukai ◽  
Kazuki Sato ◽  
Sota Ozawa ◽  
Duraisamy Kalaiselvi ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Entomopathogenic Nematode ◽  
Symbiotic Bacterium ◽  
Heterorhabditis Bacteriophora ◽  
Photorhabdus Luminescens

Physico-chemical properties and mode of action of a signal from the symbiotic bacterium Photorhabdus luminescens inducing dauer juvenile recovery in the entomopathogenic nematode Heterorhabditis bacteriophora

Nematology ◽  
2001 ◽  
Vol 3 (8) ◽  
pp. 849-853 ◽  
Author(s):  
Ralf-Udo Ehlers ◽  
Jens Aumann
Keyword(s):  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Chemical Properties ◽  
Symbiotic Bacterium ◽  
Heterorhabditis Bacteriophora ◽  
Juvenile Stage ◽  
Food Sources ◽  
Symbiotic Bacteria ◽  
Photorhabdus Luminescens ◽  
Physico Chemical

AbstractRecovery in entomopathogenic nematodes is the exit from the dauer juvenile stage. It is a response to environmental queues signalling the presence of food sources (e.g., insect haemolymph). The bacterium Photorhabdus luminescens excretes a signal which also induces recovery of its symbiotic Heterorhabditis bacteriophora dauer juveniles. This bacterial signal is composed of at least two compounds with different polarity. The symbiotic bacteria also secrete an antagonistic signal which inhibits nematode recovery. The recovery-inducing signal compounds have a molecular mass of less than 20 kDa and are negatively charged. The data indicate that at least one compound is smaller than 5 kDa. The bacterial signal triggers by receptor binding, the first step in a recovery-inducing muscarinic signalling pathway.

Isolation, bioassay and characterisation of Xenorhabdus sp. SY5, a highly virulent symbiotic bacterium of an entomopathogenic nematode isolated from China

Nematology ◽  
2013 ◽  
Vol 15 (2) ◽  
pp. 153-163 ◽  
Author(s):  
Huan Wang ◽  
Hui Dong ◽  
Haitao Qian ◽  
Runxi Xia ◽  
Bin Cong
Keyword(s):  
Growth Inhibition ◽  
Insecticidal Activity ◽  
Entomopathogenic Nematode ◽  
Symbiotic Bacterium ◽  
Symbiotic Bacteria ◽  
Toxin Gene ◽  
Agricultural Pests ◽  
Bacterial Strains ◽  
Biological Pest Control ◽  
Highly Virulent

The entomopathogenic nematodes (EPN), together with their symbiotic bacteria, are obligate and lethal parasites of insects and are applied as biological approaches to pest management. In this paper, we isolated 122 strains of symbiotic bacteria from 23 EPN isolates that were gathered in various soils containing different vegetations from different regions of China. All these isolated bacterial strains showed oral insecticidal activity and/or growth inhibition to the larvae of Ostrinia furnacalis. Among these strains, Xenorhabdus sp. SY5 exhibited high insecticidal activity to O. furnacalis, Plutella xylostella, Mythimna separata, Laphygma exigua and Tenebrio molitor, all of which are important agricultural pests. Xenorhabdus sp. SY5 was isolated from EPN Steinernema sp. SY5. Through DEAE-52 column chromatography, seven toxins were purified from X. sp. SY5. Bioassay results showed that all seven toxins had, to a certain extent, insecticidal activity and/or growth inhibition to O. furnacalis, T. molitor, P. xylostella, M. separata and L. exigua. Our data also showed that each of these toxins had different insecticidal activity and/or growth inhibition against different insect species. The partial toxin gene sequence of X. sp. SY5 was determined, and its deduced amino acid sequence only showed 75, 66 and 65% identities to homologues of EPN symbiotic bacteria Photorhabdus luminescens, Xenorhabdus nematophila and Yersinia mollaretii, respectively. These results suggested that strain SY5 is a highly virulent EPN symbiotic bacterial strain that has a potential value for biological pest control.

Photorhabdus luminescens subsp. noenieputensis subsp. nov., a symbiotic bacterium associated with a novel Heterorhabditis species related to Heterorhabditis indica

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1853-1858 ◽  
Author(s):  
Tiarin Ferreira ◽  
Carol van Reenen ◽  
Sylvie Pagès ◽  
Patrick Tailliez ◽  
Antoinette P. Malan ◽  
...  
Keyword(s):  
Type Species ◽  
Galleria Mellonella ◽  
Entomopathogenic Nematode ◽  
Symbiotic Bacterium ◽  
Tween 20 ◽  
Haemolytic Activity ◽  
Phenotypic Traits ◽  
Photorhabdus Luminescens ◽  
Content Type ◽  
Link Type

The bacterial symbiont AM7T, isolated from a novel entomopathogenic nematode species of the genus Heterorhabditis, displays the main phenotypic traits of the genus Photorhabdus and is highly pathogenic to Galleria mellonella. Phylogenetic analysis based on a multigene approach (16S rRNA, recA, gyrB, dnaN, gltX and infB) confirmed the classification of isolate AM7T within the species Photorhabdus luminescens and revealed its close relatedness to Photorhabdus luminescens subsp. caribbeanensis , P. luminescens subsp. akhurstii and P. luminescens subsp. hainanensis . The five concatenated protein-encoding sequences (4197 nt) of strain AM7T revealed 95.8, 95.4 and 94.9 % nucleotide identity to sequences of P. luminescens subsp. caribbeanensis HG29T, P. luminescens subsp. akhurstii FRG04T and P. luminescens subsp. hainanensis C8404T, respectively. These identity values are less than the threshold of 97 % proposed for classification within one of the existing subspecies of P. luminescens . Unlike other strains described for P. luminescens , strain AM7T produces acid from adonitol, sorbitol and xylitol, assimilates xylitol and has no lipase activity on medium containing Tween 20 or 60. Strain AM7T is differentiated from P. luminescens subsp. caribbeanensis by the assimilation of N-acetylglucosamine and the absence of haemolytic activity. Unlike P. luminescens subsp. akhurstii , strain AM7T does not assimilate mannitol, and it is distinguished from P. luminescens subsp. hainanensis by the assimilation of trehalose and citrate, the inability to produce indole from tryptophan and the presence of acetoin production and urease activity. Strain AM7T ( = ATCC BAA-2407T  = DSM 25462T) belongs to a novel subspecies, and is proposed as the type strain of Photorhabdus luminescens subsp. noenieputensis sp. nov.

scholarly journals Involvement of Vitamin B6Biosynthesis Pathways in the Insecticidal Activity of Photorhabdus luminescens

2016 ◽  
Vol 82 (12) ◽  
pp. 3546-3553 ◽  
Author(s):  
Kazuki Sato ◽  
Toyoshi Yoshiga ◽  
Koichi Hasegawa
Keyword(s):  
Insecticidal Activity ◽  
Genetic Screening ◽  
De Novo ◽  
Entomopathogenic Nematode ◽  
Vitamin B ◽  
Photorhabdus Luminescens ◽  
Content Type ◽  
C Elegans ◽  
Growth Deficiency ◽  
Highly Virulent

ABSTRACTPhotorhabdus luminescensis a Gram-negative entomopathogenic bacterium which symbiotically associates with the entomopathogenic nematodeHeterorhabditis bacteriophora.P. luminescensis highly virulent to many insects and nonsymbiotic nematodes, includingCaenorhabditis elegans. To understand the virulence mechanisms ofP. luminescens, we obtained virulence-deficient and -attenuated mutants againstC. elegansthrough a transposon-mutagenized library. From the genetic screening, we identified thepdxBgene, encoding erythronate-4-phosphate dehydrogenase, as required forde novovitamin B6biosynthesis. Mutation inpdxBcaused growth deficiency ofP. luminescensin nutrient-poor medium, which was restored under nutrient-rich conditions or by supplementation with pyridoxal 5′-phosphate (PLP), an active form of vitamin B6. Supplementation with three other B6vitamers (pyridoxal, pyridoxine, and pyridoxamine) also restored the growth of thepdxBmutant, suggesting the existence of a salvage pathway for vitamin B6biosynthesis inP. luminescens. Moreover, supplementation with PLP restored the virulence-deficient phenotype againstC. elegans. Combining these results with the fact thatpdxBmutation also caused attenuation of insecticidal activity, we concluded that the production of appropriate amounts of vitamin B6is critical forP. luminescenspathogenicity.IMPORTANCEThe Gram-negative entomopathogenic bacteriumPhotorhabdus luminescenssymbiotically associates with the entomopathogenic nematodeHeterorhabditis bacteriophora.P. luminescensis highly virulent to many insects and nonsymbiotic nematodes, includingCaenorhabditis elegans. We have obtained several virulence-deficient and -attenuatedP. luminescensmutants againstC. elegansthrough genetic screening. From the genetic analysis, we present the vitamin B6biosynthetic pathways inP. luminescensthat are important for its insecticidal activity. Mutation inpdxB, encoding erythronate-4-phosphate dehydrogenase and required for thede novovitamin B6biosynthesis pathway, caused virulence deficiency againstC. elegansand growth deficiency ofP. luminescensin nutrient-poor medium. Because such phenotypes were restored under nutrient-rich conditions or by supplementation with B6vitamers, we showed the presence of the two vitamin B6synthetic pathways (de novoand salvage) inP. luminescensand also showed that the ability to produce an appropriate amount of vitamin B6is critical forP. luminescenspathogenicity.

scholarly journals Draft Genome Sequence of Photorhabdus luminescens HIM3 Isolated from an Entomopathogenic Nematode in Agricultural Soils

2017 ◽  
Vol 5 (35) ◽  
Author(s):  
Rosalba Salgado-Morales ◽  
Nancy Rivera-Gómez ◽  
Fernando Martínez-Ocampo ◽  
Luis Fernando Lozano-Aguirre Beltrán ◽  
Armando Hernández-Mendoza ◽  
...  
Keyword(s):  
Genome Size ◽  
Genome Sequence ◽  
Agricultural Soils ◽  
Entomopathogenic Nematode ◽  
Draft Genome ◽  
Symbiotic Bacterium ◽  
Draft Genome Sequence ◽  
Photorhabdus Luminescens ◽  
Content Type ◽  
Heterorhabditis Indica

ABSTRACT In this work, we report the draft genome sequence of Photorhabdus luminescens strain HIM3, a symbiotic bacterium associated with the entomopathogenic nematode Heterorhabditis indica MOR03, isolated from soil sugarcane in Yautepec, Morelos, Mexico. These bacteria have a G+C content of 42.6% and genome size of 5.47 Mb.

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