المؤلفون: Yunfei Han, Shujing Zhang, Yang Wang, Jiangtao Gao, Jinhua Han, Zhiqiang Yan, Yongquan Ta, Yonghong Wang

المصدر: Scientific Reports, Vol 14, Iss 1, Pp 1-11 (2024)

مصطلحات موضوعية: Xenocoumacin 1 (Xcn1), Fermentation optimization, Xenorhabdus nematophila, Biopesticide, Response surface methodology, Medicine, Science

الوصف: Abstract Xenocoumacin 1 (Xcn 1), antibiotic discovered from secondary metabolites of Xenorhabdus nematophila, had the potential to develop into a new pesticide due to its excellent activity against bacteria, oomycetes and fungi. However, the current low yield of Xcn1 limits its development and utilization. To improve the yield of Xcn1, response surface methodology was used to determine the optimal composition of fermentation medium and one factor at a time approach was utilized to optimize the fermentation process. The optimal medium composed of in g/L: proteose peptone 20.8; maltose 12.74; K2HPO4 3.77. The optimal fermentation conditions were that 25 °C, initial pH 7.0, inoculum size 10%, culture medium 75 mL in a 250 mL shake flask with an agitation rate of 150 rpm for 48 h. Xenorhabdus nematophila YL001 was produced the highest Xcn1 yield (173.99 mg/L) when arginine was added to the broth with 3 mmol/L at the 12th h. Compared with Tryptic Soy Broth medium, the optimized fermentation process resulted in a 243.38% increase in Xcn1 production. The obtained results confirmed that optimizing fermentation technology led to an increase in Xcn1 yield. This work would be helpful for efficient Xcn1 production and lay a foundation for its industrial production.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/f0aaf6b59b7e4289ac2a2f619cdd160aTest

المؤلفون: Prajapati, M.R.¹, Maru, Ajay Kumar^{1, 1}, Raghunandan, B.L.²

المصدر: Indian Journal of Nematology 53(2):110-116. 2023

المؤلفون: Shobhi Chaudhary, Waseem Ali, Mohit Yadav, Garima Singh, Nomita Gupta, Sonam Grover, Chaitali Ghosh, Subhash Chandra, Jitendra Singh Rathore

مصطلحات موضوعية: Biochemistry, Microbiology, Cell Biology, Genetics, Infectious Diseases, Virology, Xenorhabdus nematophila, structure, ccdAB, toxin, antitoxin

الوصف: Toxin-antitoxin (TA) modules, initially discovered on bacterial plasmids and subsequently identified within chromosomal contexts, hold a pivotal role in the realm of bacterial physiology. Among these, the pioneering TA system, ccd (Control of Cell Death), primarily localized on the F-plasmid, is known for its orchestration of plasmid replication with cellular division. Nonetheless, the precise functions of such systems within bacterial chromosomal settings remain a compelling subject that demands deeper investigation. To bridge this knowledge gap, our study focuses on exploring ccdAB Xn2 , a chromosomally encoded TA module originating from the entomopathogenic bacterium Xenorhabdus nematophila . We meticulously delved into the system’s genomic assignments, structural attributes, and functional interplay. Our findings uncovered intriguing patterns—CcdB toxin homologs exhibited higher conservation levels compared to their CcdA antitoxin counterparts. Moreover, we constructed secondary as well as tertiary models for both the CcdB toxin and CcdA antitoxin using threading techniques and subsequently validated their structural integrity. Our exploration extended to the identification of key interactions, including the peptide interaction with gyrase for the CcdB homolog and CcdB toxin interactions for the CcdA homolog, highlighting the intricate TA interaction network. Through docking and simulation analyses, we unequivocally demonstrated the inhibition of replication via binding the CcdB toxin to its target, DNA gyrase. These insights provide valuable knowledge about the metabolic and physiological roles of the chromosomally encoded ccdAB Xn 2 TA module within the context of X. nematophila , significantly enhancing our comprehension of its functional significance within the intricate ecosystem of the bacterial host. Communicated by Ramaswamy H. Sarma

العلاقة: https://figshare.com/articles/journal_contribution/Computational_exploration_of_the_genomic_assignments_molecular_structure_and_dynamics_of_the_i_ccdAB_sup_Xn_sup_i_sup_i_2_i_sup_toxin-antitoxin_homolog_with_its_bacterial_target_the_DNA_gyrase_in_the_entomopathogen_i_Xenorhabdus_nematophila/25158411Test

الإتاحة: https://doi.org/10.6084/m9.figshare.25158411.v1Test
https://figshare.com/articles/journal_contribution/Computational_exploration_of_the_genomic_assignments_molecular_structure_and_dynamics_of_the_i_ccdAB_sup_Xn_sup_i_sup_i_2_i_sup_toxin-antitoxin_homolog_with_its_bacterial_target_the_DNA_gyrase_in_the_entomopathogen_i_Xenorhabdus_nematophila/25158411Test

المؤلفون: Shujing Zhang, Yunfei Han, Lanying Wang, Jinhua Han, Zhiqiang Yan, Yong Wang, Yonghong Wang

المصدر: Journal of Fungi, Vol 10, Iss 3, p 175 (2024)

مصطلحات موضوعية: Xenorhabdus nematophila, Xenocoumacin 1, antifungal activity, Sclerotinia sclerotiorum, biopesticide, Biology (General), QH301-705.5

الوصف: Sclerotinia sclerotiorum (Lib.) de Bary, a polyphagous necrotrophic fungal pathogen, has brought about significant losses in agriculture and floriculture. Until now, the most common method for controlling S. sclerotiorum has been the application of fungicides. Xenocoumacin 1 (Xcn1) is a potential biopesticide having versatile antimicrobial activities, generated by Xenorhabdus nematophila. This study was intended to isolate Xcn1 from X. nematophila YL001 and clarify its efficacies for S. sclerotiorum control. Xcn1 demonstrated a wider antifungal spectrum against 10 plant-pathogenic fungi. It also exhibited a strong inhibitory effect on the mycelial growth of S. sclerotiorum with an EC50 value of 3.00 μg/mL. Pot experiments indicated that Xcn1 effectively inhibited disease extension on oilseed rape and broad bean plants caused by S. sclerotiorum. Morphological and ultrastructural observations revealed that the hyphae of S. sclerotiorum became twisted, shriveled, and deformed at the growing points after treatment with Xcn1 at 3.00 μg/mL and that the subcellular fractions also became abnormal concurrently, especially the mitochondrial structure. Moreover, Xcn1 also increased cell membrane permeability and decreased the content of exopolysaccharide as well as suppressing the activities of polygalacturonase and cellulase of S. sclerotiorum, but exerted no effects on oxalic acid production. This study demonstrated that Xcn1 has great potential to be developed as a new biopesticide for the control of S. sclerotiorum.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2309-608X/10/3/175Test; https://doaj.org/toc/2309-608XTest

الوصول الحر: https://doaj.org/article/d9caf0afbfcb42ada04c98cba89c6d75Test

المؤلفون: Vicente-Díez, Ignacio, Pou, Alicia, Campos-Herrera, Raquel

مصطلحات موضوعية: Deterrent compounds - Lobesia botrana - oviposition cue repellence, Photorhabdus laumondii - Vitis vinifera, Volatile Organic Compounds - Xenorhabdus nematophila

وصف الملف: application/pdf

العلاقة: info:eu-repo/semantics/altIdentifier/eissn/1096-0805; info:eu-repo/semantics/altIdentifier/pissn/0022-2011; The deterrent ability of Xenorhabdus nematophila and Photorhabdus laumondii compounds as a potential novel tool for Lobesia botrana (Lepidoptera: Tortricidae) management, 2023, vol. 198; https://investigacion.unirioja.es/documentos/642b385da1c8a315fd2353edTest; urn:issn:1096-0805; urn:issn:0022-2011

الإتاحة: https://doi.org/10.1016/J.JIP.2023.107911Test
https://investigacion.unirioja.es/documentos/642b385da1c8a315fd2353edTest

المؤلفون: Jiaqi Duan, Baoming Yuan, Fenglian Jia, Xiaohui Li, Chang Chen, Guangyue Li

مصطلحات موضوعية: Biophysics, Microbiology, Genetics, Molecular Biology, Biotechnology, Developmental Biology, Infectious Diseases, Space Science, Biological Sciences not elsewhere classified, dna fragments ranging, different constitutive promoters, xenorhabdus nematophila cb6, xenorhabdus budapestensis xbd8, wt xbd8, successfully applied, significant increase, selection system, selection marker, seamlessly knocked, sacb <, one cassette, neo <, good efficiency, fclc <, fabclavine 8, fabclavine 7, dual selection, batch experiment, 788 bp

الوصف: Xenorhabdus can produce numerous natural products, but their development has been hampered by the lack of a seamless genetic manipulation method. In this study, we compared several lethal genes and determined the sacB gene as the most effective counter-selection marker and then established a dual selection/counter-selection system by integrating neo and sacB genes into one cassette. This provides an efficient and seamless genetic manipulation method for Xenorhabdus. Using this method, DNA fragments ranging from 205 to 47,788 bp in length were seamlessly knocked out or replaced with impressively high positive rates of 80 to 100% in Xenorhabdus budapestensis XBD8. In addition, the method was successfully applied with good efficiency (45–100%) in Xenorhabdus nematophila CB6. To further validate the method, different constitutive promoters were used to replace the native fclC promoter in a batch experiment. The positivity rate remained consistently high, at 46.3%. In comparison to WT XBD8, the recombinant strain MX14 demonstrated a significant increase in the production of fabclavine 7 and fabclavine 8 by 4.97-fold and 3.22-fold, respectively, while the overall production of fabclavines was enhanced by 3.52-fold.

العلاقة: https://figshare.com/articles/journal_contribution/Development_of_an_Efficient_and_Seamless_Genetic_Manipulation_Method_for_Xenorhabdus_and_Its_Application_for_Enhancing_the_Production_of_Fabclavines/24854408Test

الإتاحة: https://doi.org/10.1021/acs.jafc.3c04136.s001Test
https://figshare.com/articles/journal_contribution/Development_of_an_Efficient_and_Seamless_Genetic_Manipulation_Method_for_Xenorhabdus_and_Its_Application_for_Enhancing_the_Production_of_Fabclavines/24854408Test

المؤلفون: Haq Abdul Shaik, Archana Mishra

المصدر: Microorganisms; Volume 11; Issue 7; Pages: 1678

مصطلحات موضوعية: asafoetida, P. apterus, Steinernema carpocapsae, Xenorhabdus nematophila, virulence, pro-phenol oxidase (PPO), phenol oxidase (PO), immunity

جغرافية الموضوع: agris

الوصف: Nematode–microbe symbiosis plays a key role in determining pathogenesis against pests. The modulation of symbiotic bacteria may affect the virulence of entomopathogenic nematodes (EPNs) and the biological management of pests. We tested the influence of asafoetida (ASF) extract on the virulence of Steinernema carpocapsae and its symbiotic bacterium, Xenorhabdus nematophila, in Pyrrhocoris apterus. A total of 100 mg of ASF killed 30% of EPNs in 48 h, while P. apterus remained unaffected. The EPNs pre-treated with 100 mg of ASF influenced P. apterus’s mortality by 24–91.4% during a period of 24 to 72 h. The topical application of ASF acted as a deterrent to S. carpocapsae, lowering host invasion to 70% and delaying infectivity with 30% mortality for 168 h. Interestingly, Steinernema’s symbiotic bacterium, Xenorhabdus, remained unaffected by ASF. An in vitro turbidity test containing 100 mg of ASF in a medium increased the growth rate of Xenorhabdus compared to a control. A disc diffusion assay confirmed the non-susceptibility of Xenorhabdus to ASF compared to a positive control, streptomycin. Pro-phenol oxidase (PPO) and phenol oxidase (PO) upregulation showed that ASF influences immunity, while EPN/ASF showed a combined immunomodulatory effect in P. apterus.We report that ASF modulated the virulence of S. carpocapsae but not that of its symbiotic bacterium, X. nematophila, against P. apterus.

وصف الملف: application/pdf

العلاقة: Antimicrobial Agents and Resistance; https://dx.doi.org/10.3390/microorganisms11071678Test

الإتاحة: https://doi.org/10.3390/microorganisms11071678Test

المؤلفون: Emilie Lefoulon, Natalie Campbell, S. Patricia Stock

المصدر: PeerJ, Vol 10, p e12956 (2022)

مصطلحات موضوعية: Xenorhabdus nematophila, Prophages, Diversity, Gene expression, Induction, Phage-like particle, Medicine, Biology (General), QH301-705.5

الوصف: Background Entomopathogenic Xenorhabdus bacteria are endosymbionts of Steinernema nematodes and together they form an insecticidal mutualistic association that infects a wide range of insect species. Xenorhabdus produce an arsenal of toxins and secondary metabolites that kill the insect host. In addition, they can induce the production of diverse phage particles. A few studies have focused on one integrated phage responsible for producing a phage tail-like bacteriocin, associated with an antimicrobial activity against other Xenorhabdus species. However, very little is known about the diversity of prophage regions in Xenorhabdus species. Methods In the present study, we identified several prophage regions in the genome of Xenorhabdus nematophila AN6/1. We performed a preliminary study on the relative expression of genes in these prophage regions. We also investigated some genes (not contained in prophage region) known to be involved in SOS bacterial response (recA and lexA) associated with mitomycin C and UV exposure. Results We described two integrated prophage regions (designated Xnp3 and Xnp4) not previously described in the genome of Xenorhabdus nematophila AN6/1. The Xnp3 prophage region appears very similar to complete Mu-like bacteriophage. These prophages regions are not unique to X. nematophila species, although they appear less conserved among Xenorhabdus species when compared to the previously described p1 prophage region. Our results showed that mitomycin C exposure induced an up-regulation of recA and lexA suggesting activation of SOS response. In addition, mitomycin C and UV exposure seems to lead to up-regulation of genes in three of the four integrated prophages regions.

وصف الملف: electronic resource

العلاقة: https://peerj.com/articles/12956.pdfTest; https://peerj.com/articles/12956Test/; https://doaj.org/toc/2167-8359Test

الوصول الحر: https://doaj.org/article/2a11a28d20e34d8a912a1f50707ff789Test

المؤلفون: Han, Yunfei, Zhang, Shujing, Wang, Yang, Gao, Jiangtao, Han, Jinhua, Yan, Zhiqiang, Ta, Yongquan, Wang, Yonghong

المصدر: Sci Rep ; ISSN:2045-2322 ; Volume:14 ; Issue:1

مصطلحات موضوعية: Xenorhabdus nematophila, Biopesticide, Fermentation optimization, Response surface methodology, Xenocoumacin 1 (Xcn1)

الوصف: Xenocoumacin 1 (Xcn 1), antibiotic discovered from secondary metabolites of Xenorhabdus nematophila, had the potential to develop into a new pesticide due to its excellent activity against bacteria, oomycetes and fungi. However, the current low yield of Xcn1 limits its development and utilization. To improve the yield of Xcn1, response surface methodology was used to determine the optimal composition of fermentation medium and one factor at a time approach was utilized to optimize the fermentation process. The optimal medium composed of in g/L: proteose peptone 20.8; maltose 12.74; K2HPO4 3.77. The optimal fermentation conditions were that 25 °C, initial pH 7.0, inoculum size 10%, culture medium 75 mL in a 250 mL shake flask with an agitation rate of 150 rpm for 48 h. Xenorhabdus nematophila YL001 was produced the highest Xcn1 yield (173.99 mg/L) when arginine was added to the broth with 3 mmol/L at the 12th h. Compared with Tryptic Soy Broth medium, the optimized fermentation process resulted in a 243.38% increase in Xcn1 production. The obtained results confirmed that optimizing fermentation technology led to an increase in Xcn1 yield. This work would be helpful for efficient Xcn1 production and lay a foundation for its industrial production.

العلاقة: https://doi.org/10.1038/s41598-024-63794-2Test; https://pubmed.ncbi.nlm.nih.gov/38866882Test; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11169479Test/

الإتاحة: https://doi.org/10.1038/s41598-024-63794-2Test
https://pubmed.ncbi.nlm.nih.gov/38866882Test
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11169479Test/

المؤلفون: Lefoulon, E., Campbell, N., Stock, S.P.

المساهمون: School of Animal and Comparative Biomedical Sciences, University of Arizona

المصدر: PeerJ

مصطلحات موضوعية: Diversity, Gene expression, Induction, Mitomycin, Phage-like particle, Prophages, UV, Xenorhabdus nematophila

الوصف: Background: Entomopathogenic Xenorhabdus bacteria are endosymbionts of Steinernema nematodes and together they form an insecticidal mutualistic association that infects a wide range of insect species. Xenorhabdus produce an arsenal of toxins and secondary metabolites that kill the insect host. In addition, they can induce the production of diverse phage particles. A few studies have focused on one integrated phage responsible for producing a phage tail-like bacteriocin, associated with an antimicrobial activity against other Xenorhabdus species. However, very little is known about the diversity of prophage regions in Xenorhabdus species. Methods: In the present study, we identified several prophage regions in the genome of Xenorhabdus nematophila AN6/1. We performed a preliminary study on the relative expression of genes in these prophage regions. We also investigated some genes (not contained in prophage region) known to be involved in SOS bacterial response (recA and lexA) associated with mitomycin C and UV exposure. Results: We described two integrated prophage regions (designated Xnp3 and Xnp4) not previously described in the genome of Xenorhabdus nematophila AN6/1. The Xnp3 prophage region appears very similar to complete Mu-like bacteriophage. These prophages regions are not unique to X. nematophila species, although they appear less conserved among Xenorhabdus species when compared to the previously described p1 prophage region. Our results showed that mitomycin C exposure induced an up-regulation of recA and lexA suggesting activation of SOS response. In addition, mitomycin C and UV exposure seems to lead to up-regulation of genes in three of the four integrated prophages regions. Copyright 2022 Lefoulon et al. ; Open access journal ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.

العلاقة: Lefoulon, E., Campbell, N., & Stock, S. P. (2022). Identification of novel prophage regions in Xenorhabdus nematophila genome and gene expression analysis during phage-like particle induction. PeerJ.; http://hdl.handle.net/10150/663854Test; PeerJ

الإتاحة: https://doi.org/10.7717/peerj.12956Test
http://hdl.handle.net/10150/663854Test