-
Journal of Applied Microbiology Jun 2024This study aimed to overproduce industrially relevant and safe bio-compound trans-cinnamic acid (tCA) from Photorhabdus luminescens with deletion strategies and...
AIM
This study aimed to overproduce industrially relevant and safe bio-compound trans-cinnamic acid (tCA) from Photorhabdus luminescens with deletion strategies and homologous expression strategies that had not been applied before for tCA production.
METHODS AND RESULTS
The overproduction of the industrially relevant compound tCA was successfully performed in Photorhabdus luminescens by deleting stlB (TTO1ΔstlB) encoding a cinnamic acid CoA ligase in the isopropylstilbene pathway and the hcaE insertion (knockout) mutation (hcaE:: cat) in the phenylpropionate catabolic pathway, responsible for tCA degradation. A double mutant of both stlB deletion and hcaE insertion mutation (TTO1DM ΔstlB-hcaE:: cat) was also generated. These deletion strategies and the phenylalanine ammonium lyase-producing (PI-PAL from Photorhabdus luminescens) plasmid, pBAD30C, carrying stlA (homologous expression mutants) are utilized together in the same strain using different media, a variety of cultivation conditions, and efficient anion exchange resin (Amberlite IRA402) for enhanced tCA synthesis. At the end of the 120-hour shake flask cultivation, the maximum tCA production was recorded as 1281 mg L-1 in the TTO1pBAD30C mutant cultivated in TB medium, with the IRA402 resin keeping 793 mg L-1 and the remaining 488 mg L-1 found in the supernatant.
CONCLUSION AND IMPACT OF THE STUDY
tCA production was successfully achieved with homologous expression, coupled with deletion and insertion strategies. 1281 mg L-1is the highest tCA concentration that achieved by bacterial tCA production in flask cultivation, according to our knowledge. IRA402 resin adsorbers seem useful for enhancing tCA acquisition in bacterial cultures. Mutations on the hcaE and stlB genes clearly increased the amount of tCA. P. luminescens is an effective bacterial candidate to produce tCA in industrial applications with the implemented strategies.
PubMed: 38906846
DOI: 10.1093/jambio/lxae149 -
Cell Chemical Biology Aug 2023Darobactins represent a class of ribosomally synthesized and post-translationally modified peptide (RiPP) antibiotics featuring a rare bicyclic structure. They target...
Darobactins represent a class of ribosomally synthesized and post-translationally modified peptide (RiPP) antibiotics featuring a rare bicyclic structure. They target the Bam-complex of Gram-negative bacteria and exhibit in vivo activity against drug-resistant pathogens. First isolated from Photorhabdus species, the corresponding biosynthetic gene clusters (BGCs) are widespread among γ-proteobacteria, including the genera Vibrio, Yersinia, and Pseudoalteromonas (P.). While the organization of the BGC core is highly conserved, a small subset of Pseudoalteromonas carries an extended BGC with additional genes. Here, we report the identification of brominated and dehydrated darobactin derivatives from P. luteoviolacea strains. The marine derivatives are active against multidrug-resistant (MDR) Gram-negative bacteria and showed solubility and plasma protein binding ability different from darobactin A, rendering it more active than darobactin A. The halogenation reaction is catalyzed by DarH, a new class of flavin-dependent halogenases with a novel fold.
Topics: Phenylpropionates; Gram-Negative Bacteria; Metabolome
PubMed: 37451267
DOI: 10.1016/j.chembiol.2023.06.011 -
Nature Reviews. Microbiology Sep 2014Bacterial ADP-ribosyltransferase toxins (bARTTs) transfer ADP-ribose to eukaryotic proteins to promote bacterial pathogenesis. In this Review, we use prototype bARTTs,... (Review)
Review
Bacterial ADP-ribosyltransferase toxins (bARTTs) transfer ADP-ribose to eukaryotic proteins to promote bacterial pathogenesis. In this Review, we use prototype bARTTs, such as diphtheria toxin and pertussis toxin, as references for the characterization of several new bARTTs from human, insect and plant pathogens, which were recently identified by bioinformatic analyses. Several of these toxins, including cholix toxin (ChxA) from Vibrio cholerae, SpyA from Streptococcus pyogenes, HopU1 from Pseudomonas syringae and the Tcc toxins from Photorhabdus luminescens, ADP-ribosylate novel substrates and have unique organizations, which distinguish them from the reference toxins. The characterization of these toxins increases our appreciation of the range of structural and functional properties that are possessed by bARTTs and their roles in bacterial pathogenesis.
Topics: ADP Ribose Transferases; Adenosine Diphosphate Ribose; Animals; Bacteria; Bacterial Toxins; Computational Biology; Humans; Insecta; Models, Molecular; Plants; Signal Transduction
PubMed: 25023120
DOI: 10.1038/nrmicro3310 -
Insects Aug 2020This special issue contains articles that add to the ever-expanding toolbox of insect pathogenic nematodes (entomopathogenic nematodes; EPNs) as well articles that...
This special issue contains articles that add to the ever-expanding toolbox of insect pathogenic nematodes (entomopathogenic nematodes; EPNs) as well articles that provide new insights into the mutualistic interaction between EPNs and their hosts. The study of natural infection models such as EPNs allows detailed insight into micro- and macro-evolutionary dynamics of innate immune reactions, including known but also emerging branches of innate immunity. Additional new insights into the kinetics of EPN infections are gained by increased spatiotemporal resolution of advanced transcriptome studies and live imaging.
PubMed: 32872298
DOI: 10.3390/insects11090577 -
Insects Apr 2015The scientific community working in the field of insect pathology is experiencing an increasing academic and industrial interest in the discovery and development of new... (Review)
Review
The scientific community working in the field of insect pathology is experiencing an increasing academic and industrial interest in the discovery and development of new bioinsecticides as environmentally friendly pest control tools to be integrated, in combination or rotation, with chemicals in pest management programs. In this scientific context, market data report a significant growth of the biopesticide segment. Acquisition of new technologies by multinational Ag-tech companies is the center of the present industrial environment. This trend is in line with the requirements of new regulations on Integrated Pest Management. After a few decades of research on microbial pest management dominated by Bacillus thuringiensis (Bt), novel bacterial species with innovative modes of action are being discovered and developed into new products. Significant cases include the entomopathogenic nematode symbionts Photorhabdus spp. and Xenorhabdus spp., Serratia species, Yersinia entomophaga, Pseudomonas entomophila, and the recently discovered Betaproteobacteria species Burkholderia spp. and Chromobacterium spp. Lastly, Actinobacteria species like Streptomyces spp. and Saccharopolyspora spp. have gained high commercial interest for the production of a variety of metabolites acting as potent insecticides. With the aim to give a timely picture of the cutting-edge advancements in this renewed research field, different representative cases are reported and discussed.
PubMed: 26463190
DOI: 10.3390/insects6020352 -
Trends in Parasitology Jan 2020Xenorhabdus and Photorhabdus species are symbiotic bacteria of the insect-pathogenic soil nematodes that produce insecticidal compounds lethal to prey insects. Recently,... (Review)
Review
Xenorhabdus and Photorhabdus species are symbiotic bacteria of the insect-pathogenic soil nematodes that produce insecticidal compounds lethal to prey insects. Recently, there has been much interest in adapting these insecticidals for mosquito control. Here, I advocate the potential of Xenorhabdus/Photorhabdus as natural sources of mosquitocides (larvicides, adulticides) and feeding-deterrents.
Topics: Animals; Culicidae; Insecticides; Mosquito Control; Nematoda; Photorhabdus; Symbiosis; Xenorhabdus
PubMed: 31375436
DOI: 10.1016/j.pt.2019.07.003 -
Nature Microbiology Oct 2022Discovery of antibiotics acting against Gram-negative species is uniquely challenging due to their restrictive penetration barrier. BamA, which inserts proteins into the...
Discovery of antibiotics acting against Gram-negative species is uniquely challenging due to their restrictive penetration barrier. BamA, which inserts proteins into the outer membrane, is an attractive target due to its surface location. Darobactins produced by Photorhabdus, a nematode gut microbiome symbiont, target BamA. We reasoned that a computational search for genes only distantly related to the darobactin operon may lead to novel compounds. Following this clue, we identified dynobactin A, a novel peptide antibiotic from Photorhabdus australis containing two unlinked rings. Dynobactin is structurally unrelated to darobactins, but also targets BamA. Based on a BamA-dynobactin co-crystal structure and a BAM-complex-dynobactin cryo-EM structure, we show that dynobactin binds to the BamA lateral gate, uniquely protruding into its β-barrel lumen. Dynobactin showed efficacy in a mouse systemic Escherichia coli infection. This study demonstrates the utility of computational approaches to antibiotic discovery and suggests that dynobactin is a promising lead for drug development.
Topics: Animals; Anti-Bacterial Agents; Bacterial Outer Membrane Proteins; Escherichia coli; Escherichia coli Proteins; Gram-Negative Bacteria; Mice; Peptides; Phenylpropionates
PubMed: 36163500
DOI: 10.1038/s41564-022-01227-4 -
International Journal of Systematic and... Jan 2021Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria, BA1, Q614 and PB68.1, isolated from the digestive system of entomopathogenic nematodes, were...
Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria, BA1, Q614 and PB68.1, isolated from the digestive system of entomopathogenic nematodes, were biochemically and molecularly characterized to clarify their taxonomic affiliations. The 16S rRNA gene sequences of these strains suggest that they belong to the Gammaproteobacteria, to the family , and to the genus . Deeper analyses using whole genome-based phylogenetic reconstructions suggest that BA1 is closely related to , that Q614 is closely related to and that PB68.1 is closely related to genomic comparisons confirm these observations: BA1 and 15138 share 68.8 % digital DNA-DNA hybridization (dDDH), Q614 and SF41 share 75.4 % dDDH, and PB68.1 and DSM 17609 share 76.6 % dDDH. Physiological and biochemical characterizations reveal that these three strains also differ from all validly described species and from their more closely related taxa, contrary to what was previously suggested. We therefore propose to classify BA1 as a new species within the genus , Q614 as a new subspecies within and PB68.1 as a new subspecies within . Hence, the following names are proposed for these strains: sp. nov. with the type strain BA1(=DSM 111180=CCOS 1943=LMG 31957), subsp subsp. nov. with the type strain Q614 (=DSM 111144=CCOS 1944=LMG 31959) and subsp subsp. nov. with the type strain PB68.1 (=DSM 111145=CCOS 1942). These propositions automatically create subsp subsp. nov. with SF41 as the type strain (currently classified as ) and subsp. subsp. nov. with DSM17609 as the type strain (currently classified as ).
Topics: Animals; Australia; Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Digestive System; Egypt; Nematoda; Nucleic Acid Hybridization; Photorhabdus; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Thailand
PubMed: 33464198
DOI: 10.1099/ijsem.0.004610 -
The Journal of Antibiotics Aug 2016Photorhabdus luminescens is a bioluminescent entomopathogenic bacterium that undergoes phenotypic variation and lives in mutualistic association with nematodes of the...
Photorhabdus luminescens is a bioluminescent entomopathogenic bacterium that undergoes phenotypic variation and lives in mutualistic association with nematodes of the family Heterorhabditidae. The pair infects and kills insects, and during their coordinated lifecycle, the bacteria produce an assortment of specialized metabolites to regulate its mutualistic and pathogenic roles. As part of our search for new specialized metabolites from the Photorhabdus genus, we examined organic extracts from P. luminescens grown in an amino-acid-rich medium based on the free amino-acid levels found in the circulatory fluid of its common insect prey, the Galleria mellonella larva. Reversed-phase HPLC/UV/MS-guided fractionation of the culture extracts led to the identification of two new pyrazinone metabolites, lumizinones A (1) and B (2), together with two N-acetyl dipeptides (3 and 4). The lumizinones were produced only in the phenotypic variant associated with nematode development and insect pathogenesis. Their chemical structures were elucidated by analysis of 1D and 2D NMR and high-resolution ESI-QTOF-MS spectral data. The absolute configurations of the amino acids in 3 and 4 were determined by Marfey's analysis. Compounds 1-4 were evaluated for their calpain protease inhibitory activity, and lumizinone A (1) showed inhibition with an IC50 (half-maximal inhibitory concentration) value of 3.9 μm.
Topics: Amino Acids; Animals; Chromatography, High Pressure Liquid; Inhibitory Concentration 50; Lepidoptera; Magnetic Resonance Spectroscopy; Mass Spectrometry; Photorhabdus; Protease Inhibitors; Pyrazines; Spectrometry, Mass, Electrospray Ionization
PubMed: 27353165
DOI: 10.1038/ja.2016.79 -
Natural Product Reports Apr 2018Covering: up to November 2017 Organismic interaction is one of the fundamental principles for survival in any ecosystem. Today, numerous examples show the interaction... (Review)
Review
Covering: up to November 2017 Organismic interaction is one of the fundamental principles for survival in any ecosystem. Today, numerous examples show the interaction between microorganisms like bacteria and higher eukaryotes that can be anything between mutualistic to parasitic/pathogenic symbioses. There is also increasing evidence that microorganisms are used by higher eukaryotes not only for the supply of essential factors like vitamins but also as biological weapons to protect themselves or to kill other organisms. Excellent examples for such systems are entomopathogenic nematodes of the genera Heterorhabditis and Steinernema that live in mutualistic symbiosis with bacteria of the genera Photorhabdus and Xenorhabdus, respectively. Although these systems have been used successfully in organic farming on an industrial scale, it was only shown during the last 15 years that several different natural products (NPs) produced by the bacteria play key roles in the complex life cycle of the bacterial symbionts, the nematode host and the insect prey that is killed by and provides nutrients for the nematode-bacteria pair. Since the bacteria can switch from mutualistic to pathogenic lifestyle, interacting with two different types of higher eukaryotes, and since the full system with all players can be established in the lab, they are promising model systems to elucidate the natural function of microbial NPs. This review summarizes the current knowledge as well as open questions for NPs from Photorhabdus and Xenorhabdus and tries to assign their roles in the tritrophic relationship.
Topics: Animals; Bacteria; Bacterial Physiological Phenomena; Biological Products; Host-Pathogen Interactions; Insecta; Life Cycle Stages; Nematoda; Organic Agriculture; Photorhabdus; Symbiosis; Xenorhabdus
PubMed: 29359226
DOI: 10.1039/c7np00054e