scholarly journals Identification of Putative Novel Class-I Lanthipeptides in Firmicutes: A Combinatorial In Silico Analysis Approach Performed on Genome Sequenced Bacteria and a Close Inspection of Z-Geobacillin Lanthipeptide Biosynthesis Gene Cluster of the Thermophilic Geobacillus sp. Strain ZGt-1

2018 ◽  
Vol 19 (9) ◽  
pp. 2650 ◽  
Author(s):  
Rawana N. Alkhalili ◽  
Björn Canbäck
Keyword(s):  
Genome Mining ◽  
In Silico Analysis ◽  
Gene Clusters ◽  
Class I ◽  
Bacterial Strains ◽  
In Vitro Production ◽  
Biosynthesis Gene Cluster ◽  
Bioinformatic Tools ◽  
Genome Annotations

Lanthipeptides are ribosomally synthesized and post-translationally modified polycyclic peptides. Lanthipeptides that have antimicrobial activity are known as lantibiotics. Accordingly, the discovery of novel lantibiotics constitutes a possible solution for the problem of antibiotic resistance. We utilized the publicly available genome sequences and the bioinformatic tools tailored for the detection of lanthipeptides. We designed our strategy for screening of 252 firmicute genomes and detecting class-I lanthipeptide-coding gene clusters. The designed strategy resulted in identifying 69 class-I lanthipeptide sequences, of which more than 10% were putative novel. The identified putative novel lanthipeptides have not been annotated on the original or the RefSeq genomes, or have been annotated merely as coding for hypothetical proteins. Additionally, we identified bacterial strains that have not been previously recognized as lanthipeptide-producers. Moreover, we suggest corrections for certain firmicute genome annotations, and recommend lanthipeptide records for enriching the bacteriocin genome mining tool (BAGEL) databases. Furthermore, we propose Z-geobacillin, a putative class-I lanthipeptide coded on the genome of the thermophilic strain Geobacillus sp. ZGt-1. We provide lists of putative novel lanthipeptide sequences and of the previously unrecognized lanthipeptide-producing bacterial strains, so they can be prioritized for experimental investigation. Our results are expected to benefit researchers interested in the in vitro production of lanthipeptides.

scholarly journals Overproduction of Ristomycin A by Activation of a Silent Gene Cluster in Amycolatopsis japonicum MG417-CF17

2014 ◽  
Vol 58 (10) ◽  
pp. 6185-6196 ◽  
Author(s):  
Marius Spohn ◽  
Norbert Kirchner ◽  
Andreas Kulik ◽  
Angelika Jochim ◽  
Felix Wolf ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gene Cluster ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Genome Mining ◽  
Gene Clusters ◽  
Von Willebrand Disease ◽  
Biosynthesis Gene Cluster ◽  
Content Type ◽  
Bioinformatic Tools

ABSTRACTThe emergence of antibiotic-resistant pathogenic bacteria within the last decades is one reason for the urgent need for new antibacterial agents. A strategy to discover new anti-infective compounds is the evaluation of the genetic capacity of secondary metabolite producers and the activation of cryptic gene clusters (genome mining). One genus known for its potential to synthesize medically important products isAmycolatopsis. However,Amycolatopsis japonicumdoes not produce an antibiotic under standard laboratory conditions. In contrast to mostAmycolatopsisstrains,A. japonicumis genetically tractable with different methods. In order to activate a possible silent glycopeptide cluster, we introduced a gene encoding the transcriptional activator of balhimycin biosynthesis, thebbrgene fromAmycolatopsis balhimycina(bbrAba), intoA. japonicum. This resulted in the production of an antibiotically active compound. Following whole-genome sequencing ofA. japonicum, 29 cryptic gene clusters were identified by genome mining. One of these gene clusters is a putative glycopeptide biosynthesis gene cluster. Using bioinformatic tools, ristomycin (syn. ristocetin), a type III glycopeptide, which has antibacterial activity and which is used for the diagnosis of von Willebrand disease and Bernard-Soulier syndrome, was deduced as a possible product of the gene cluster. Chemical analyses by high-performance liquid chromatography and mass spectrometry (HPLC-MS), tandem mass spectrometry (MS/MS), and nuclear magnetic resonance (NMR) spectroscopy confirmed thein silicoprediction that the recombinantA. japonicum/pRM4-bbrAbasynthesizes ristomycin A.

scholarly journals Bacteriocins of Non-aureus Staphylococci Isolated from Bovine Milk

2017 ◽  
Vol 83 (17) ◽  
Author(s):  
Domonique A. Carson ◽  
Herman W. Barkema ◽  
Sohail Naushad ◽  
Jeroen De Buck
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Genome Mining ◽  
Bovine Milk ◽  
Gene Clusters ◽  
Antibiotic Use ◽  
Content Type ◽  
Treatment And Prevention ◽  
Whole Genomes

ABSTRACT Non-aureus staphylococci (NAS), the bacteria most commonly isolated from the bovine udder, potentially protect the udder against infection by major mastitis pathogens due to bacteriocin production. In this study, we determined the inhibitory capability of 441 bovine NAS isolates (comprising 26 species) against bovine Staphylococcus aureus. Furthermore, inhibiting isolates were tested against a human methicillin-resistant S. aureus (MRSA) isolate using a cross-streaking method. We determined the presence of bacteriocin clusters in NAS whole genomes using genome mining tools, BLAST, and comparison of genomes of closely related inhibiting and noninhibiting isolates and determined the genetic organization of any identified bacteriocin biosynthetic gene clusters. Forty isolates from 9 species (S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. saprophyticus, S. sciuri, S. simulans, S. warneri, and S. xylosus) inhibited growth of S. aureus in vitro, 23 isolates of which, from S. capitis, S. chromogenes, S. epidermidis, S. pasteuri, S. simulans, and S. xylosus, also inhibited MRSA. One hundred five putative bacteriocin gene clusters encompassing 6 different classes (lanthipeptides, sactipeptides, lasso peptides, class IIa, class IIc, and class IId) in 95 whole genomes from 16 species were identified. A total of 25 novel bacteriocin precursors were described. In conclusion, NAS from bovine mammary glands are a source of potential bacteriocins, with >21% being possible producers, representing potential for future characterization and prospective clinical applications. IMPORTANCE Mastitis (particularly infections caused by Staphylococcus aureus) costs Canadian dairy producers $400 million/year and is the leading cause of antibiotic use on dairy farms. With increasing antibiotic resistance and regulations regarding use, there is impetus to explore bacteriocins (bacterially produced antimicrobial peptides) for treatment and prevention of bacterial infections. We examined the ability of 441 NAS bacteria from Canadian bovine milk samples to inhibit growth of S. aureus in the laboratory. Overall, 9% inhibited growth of S. aureus and 58% of those also inhibited MRSA. In NAS whole-genome sequences, we identified >21% of NAS as having bacteriocin genes. Our study represents a foundation to further explore NAS bacteriocins for clinical use.

scholarly journals In Silico Analysis of the Antigenic Properties of Iron-Regulated Proteins against Neisseria meningitidis

2020 ◽  
Vol 10 (17) ◽  
pp. 6113
Author(s):  
Md. Shahedur Rahman ◽  
Chayon Biswas ◽  
Polash Kumar Biswas ◽  
Md. Ashraful Kader ◽  
S. M. Nur Alam ◽  
...  
Keyword(s):  
Neisseria Meningitidis ◽  
Outer Membrane Proteins ◽  
Treatment Strategies ◽  
In Silico Analysis ◽  
Analysis Data ◽  
Bioinformatic Tools ◽  
Antigenic Properties ◽  
Potential Vaccine

Neisseria meningitidis is a commensal pathogen that causes infectious cerebrospinal disease in people of all ages. The multivariate role of six disease-causing polysaccharide serotypes is found to play a crucial role in developing vaccines (or general treatment strategies) to treat this emerging pathogen. Iron is a crucial transition metal for N. meningitidis. Proteomic analysis data could be valuable for vaccine design. Here, we conduct a comparative study using computational bioinformatic tools to identify the most effective iron-regulated outer membrane proteins (OMPs) as immunogenic targets for a potential vaccine against N. meningitidis. The basic properties of N. meningitidis OMPs are explored for flexibility, solubility, hydrophilicity, beta-turns, and overall antigenic probability. Results of our study suggest that iron-regulated OMPs are flexible and soluble in water with high densities of conformational B-cell epitopes. As such, they can be recommended as a novel candidate for a vaccine against N. meningitidis both in vitro and in vivo.

scholarly journals Genomic and Metabolomic Analysis of Antarctic Bacteria Revealed Culture and Elicitation Conditions for the Production of Antimicrobial Compounds

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 673
Author(s):  
Kattia Núñez-Montero ◽  
Damián Quezada-Solís ◽  
Zeinab G. Khalil ◽  
Robert J. Capon ◽  
Fernando D. Andreote ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Culture Media ◽  
Genome Mining ◽  
Gene Clusters ◽  
Culture Conditions ◽  
Bioactive Metabolites ◽  
Bacterial Strains ◽  
Antarctic Bacteria ◽  
New Antibiotics

Concern about finding new antibiotics against drug-resistant pathogens is increasing every year. Antarctic bacteria have been proposed as an unexplored source of bioactive metabolites; however, most biosynthetic gene clusters (BGCs) producing secondary metabolites remain silent under common culture conditions. Our work aimed to characterize elicitation conditions for the production of antibacterial secondary metabolites from 34 Antarctic bacterial strains based on MS/MS metabolomics and genome mining approaches. Bacterial strains were cultivated under different nutrient and elicitation conditions, including the addition of lipopolysaccharide (LPS), sodium nitroprusside (SNP), and coculture. Metabolomes were obtained by HPLC-QTOF-MS/MS and analyzed through molecular networking. Antibacterial activity was determined, and seven strains were selected for genome sequencing and analysis. Biosynthesis pathways were activated by all the elicitation treatments, which varies among strains and dependents of culture media. Increased antibacterial activity was observed for a few strains and addition of LPS was related with inhibition of Gram-negative pathogens. Antibiotic BGCs were found for all selected strains and the expressions of putative actinomycin, carotenoids, and bacillibactin were characterized by comparison of genomic and metabolomic data. This work established the use of promising new elicitors for bioprospection of Antarctic bacteria and highlights the importance of new “-omics” comparative approaches for drug discovery.

scholarly journals Coregulation by Phenylacetyl-Coenzyme A-Responsive PaaX Integrates Control of the Upper and Lower Pathways for Catabolism of Styrene by Pseudomonas sp. Strain Y2

2006 ◽  
Vol 188 (13) ◽  
pp. 4812-4821 ◽  
Author(s):  
Teresa del Peso-Santos ◽  
David Bartolomé-Martín ◽  
Cristina Fernández ◽  
Sergio Alonso ◽  
José Luis García ◽  
...  
Keyword(s):  
Binding Sites ◽  
Coenzyme A ◽  
Regulatory Protein ◽  
In Silico Analysis ◽  
Gene Clusters ◽  
Dependent Manner ◽  
Dnase I Footprinting ◽  
Gene Copies ◽  
Repressor Proteins

ABSTRACT The PstyA promoter of Pseudomonas sp. strain Y2 controls expression of the styABCD genes, which are required for the conversion of styrene to phenylacetate, which is further catabolized by the products of two paa gene clusters. Two PaaX repressor proteins (PaaX1 and PaaX2) regulate transcription of the paa gene clusters of this strain. In silico analysis of the PstyA promoter region revealed a sequence located just within styA that is similar to the reported PaaX binding sites of Escherichia coli and the proposed PaaX binding sites of the paa genes of Pseudomonas species. Here we show that protein extracts from some Pseudomonas strains that have paaX genes, but not from a paaX mutant strain, can bind and retard the migration of a PstyA specific probe. Purified maltose-binding protein (MBP)-PaaX1 fusion protein specifically binds the PstyA promoter proximal PaaX site, and this binding is eliminated by the addition of phenylacetyl-coenzyme A. The sequence protected by MBP-PaaX1 binding was defined by DNase I footprinting. Moreover, MBP-PaaX1 represses transcription from the PstyA promoter in a phenylacetyl-coenzyme A-dependent manner in vitro. Finally, the inactivation of both paaX gene copies of Pseudomonas sp. strain Y2 leads to a higher level of transcription from the PstyA promoter, while heterologous expression of the PaaX1 in E. coli greatly decreases transcription from the PstyA promoter. These findings reveal a control mechanism that integrates regulation of styrene catabolism by coordinating the expression of the styrene upper catabolic operon to that of the paa-encoded central pathway and support a role for PaaX as a major regulatory protein in the phenylacetyl-coenzyme A catabolon through its response to the levels of this central metabolite.

scholarly journals A widespread family of bacterial gene clusters produces ClpP inhibitors

2021 ◽  
Author(s):  
Gerry Wright ◽  
Elizabeth Culp ◽  
David Sychantha ◽  
Christian Hobson ◽  
Andrew Pawlowski ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Genome Mining ◽  
Antibiotic Resistance Genes ◽  
Gene Clusters ◽  
Biosynthetic Gene Clusters ◽  
Bacterial Gene ◽  
Clinical Potential ◽  
Novel Scaffold

Abstract Intracellular proteolytic complexes play an essential role in modeling the proteome in both bacteria and eukaryotes. ClpP is the protease subunit of one such highly conserved proteolytic complex that, despite its potential, remains unexploited as a drug target. Here we describe a target-directed genome mining strategy to identify ClpP targeting compounds from the bacterial order Actinomycetales. By searching for biosynthetic gene clusters that contain duplicated copies of ClpP as putative antibiotic resistance genes, we identify a family of ClpP-associated clusters that are widespread across phyla, including environmental and pathogenic bacteria. While numerous bacterial pyrrolizidine alkaloids produced by these gene clusters are known, their connection to ClpP has never been made. We show that these previously characterized molecules do not affect ClpP function but are shunt metabolites derived from the genuine product of these gene clusters, a reactive covalent ClpP inhibitor. Focusing on one such cryptic gene cluster from Streptomyces cattleya DSM 46488, we use heterologous expression to purify the relevant ClpP inhibitor, which we name clipibicyclene. We show in vitro and in vivo that clipibicyclene is a potent covalent inhibitor of ClpP and that cluster-associated ClpPs provide resistance. ClpP inhibition results in antibacterial activity against actinobacteria, including Mycobacterium smegmatis, and inhibition of virulence factor production by Staphylococcus aureus. Finally, we solve the crystal structure of clipibicyclene-modified Escherichia coli ClpP. Clipibicyclene’s discovery deconvolutes the actual function of a family of natural products widespread in nature. It provides a novel scaffold for therapeutic ClpP inhibitor development, making these findings significant from the perspective of their discovery and their clinical potential.

scholarly journals A Pseudoalteromonas clade with remarkable biosynthetic potential

2021 ◽  
Author(s):  
Rocky Chau ◽  
Leanne A. Pearson ◽  
Jesse Cain ◽  
John A. Kalaitzis ◽  
Brett A. Neilan
Keyword(s):  
Natural Products ◽  
Gene Cluster ◽  
Genome Mining ◽  
Gene Clusters ◽  
Average Density ◽  
Biologically Active ◽  
Biosynthesis Gene Cluster ◽  
Diverse Range ◽  
Siderophore Biosynthesis ◽  
Biosynthesis Gene

Pseudoalteromonas species produce a diverse range of biologically active compounds, including those biosynthesized by non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs). Here we report the biochemical and genomic analysis of Pseudoalteromonas sp. HM-SA03, isolated from the blue-ringed octopus, Hapalochalaena sp. Genome mining for secondary metabolite pathways revealed seven putative NRPS/PKS biosynthesis gene clusters, including those for the biosynthesis of alterochromides, pseudoalterobactins, alteramides and four hitherto novel compounds. Among these was a novel siderophore biosynthesis gene cluster with unprecedented architecture (NRPS-PKS-NRPS-PKS-NRPS-PKS-NRPS). Alterochromide production in HM-SA03 was also confirmed by liquid chromatography-mass spectrometry. An investigation of the biosynthetic potential of 42 publicly available Pseudoalteromonas genomes indicated that some of these gene clusters are distributed throughout the genus. Through phylogenetic analysis, a particular subset of strains formed a clade with extraordinary biosynthetic potential, with an average density of ten biosynthesis gene clusters per genome. In contrast, the majority of Pseudoalteromonas strains outside this clade contained an average of three clusters encoding complex biosynthesis. These results highlight the under-explored potential of Pseudoalteromonas as a source of new natural products. Importance This study demonstrates that the Pseudoalteromonas strain, HM-SA03, isolated from the venomous blue-ringed octopus, Hapalochalaena sp., is a biosynthetically talented organism, capable of producing alterochromides and potentially six other specialized metabolites. We have identified a pseudoalterobactin biosynthesis gene cluster and proposed a pathway for the production of the associated siderophore. A novel siderophore biosynthesis gene cluster with unprecedented architecture was also identified in the HM-SA03 genome. Finally, we have demonstrated that HM-SA03 belongs to a phylogenetic clade of strains with extraordinary biosynthetic potential. While our results do not support a role of HM-SA03 in Hapalochalaena sp. venom (tetrodotoxin) production, they emphasize the untapped potential of Pseudoalteromonas as a source of novel natural products.

scholarly journals Potential of Pseudomonas chlororaphis subsp. aurantiaca Strain Pcho10 as a Biocontrol Agent Against Fusarium graminearum

2014 ◽  
Vol 104 (12) ◽  
pp. 1289-1297 ◽  
Author(s):  
Weiqun Hu ◽  
Qixun Gao ◽  
Mohamed Sobhy Hamada ◽  
Dawood Hosni Dawood ◽  
Jingwu Zheng ◽  
...  
Keyword(s):  
Fusarium Head Blight ◽  
Fusarium Graminearum ◽  
Biocontrol Agent ◽  
Identification System ◽  
Pseudomonas Chlororaphis ◽  
Bacterial Strains ◽  
Head Blight ◽  
Biosynthesis Gene Cluster ◽  
Microbial Identification

To develop an effective biocontrol strategy for management of Fusarium head blight on wheat caused by Fusarium graminearum, the bacterial biocontrol agent Pcho10 was selected from more than 1,476 wheat-head-associated bacterial strains according to its antagonistic activity in vitro. This strain was subsequently characterized as Pseudomonas chlororaphis subsp. aurantiaca based on 16S ribosomal DNA sequence analysis, assays of the BIOLOG microbial identification system, and unique pigment production. The major antifungal metabolite produced by Pcho10 was further identified as phenazine-1-carboxamide (PCN) on the basis of nuclear magnetic resonance data. The core PCN biosynthesis gene cluster in Pcho10 was cloned and sequenced. PCN showed strong inhibitory activity against F. graminearum conidial germination, mycelial growth, and deoxynivalenol production. Tests both under growth chamber conditions and in field trials showed that Pcho10 well colonized on the wheat head and effectively controlled the disease caused by F. graminearum. Results of this study indicate that P. chlororaphis subsp. aurantiaca Pcho10 has high potential to be developed as a biocontrol agent against F. graminearum. To our knowledge, this is the first report of the use of P. chlororaphis for the management of Fusarium head blight.

scholarly journals Connecting the Lab and the Field: Genome Analysis of Phyllobacterium and Rhizobium Strains and Field Performance on Two Vegetable Crops

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1124
Author(s):  
José David Flores-Félix ◽  
Encarna Velázquez ◽  
Eustoquio Martínez-Molina ◽  
Fernando González-Andrés ◽  
Andrea Squartini ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Promotion ◽  
Genome Mining ◽  
Field Performance ◽  
In Silico Analysis ◽  
Homoserine Lactone ◽  
Plant Colonization ◽  
Vegetable Crops ◽  
Bacterial Strains ◽  
Acetic Acid Production

The legume nodules are a rich source not only of rhizobia but also of endophytic bacteria exhibiting plant growth-promoting mechanisms with potential as plant biostimulants. In this work we analyzed the genomes of Phyllobacterium endophyticum PEPV15 and Rhizobium laguerreae PEPV16 strains, both isolated from Phaseolus vulgaris nodules. In silico analysis showed that the genomes of these two strains contain genes related to N-acyl-homoserine lactone (AHL) and cellulose biosynthesis, involved in quorum sensing and biofilm formation, which are essential for plant colonization. Several genes involved in plant growth promotion such as those related to phosphate solubilization, indole acetic acid production, siderophore biosynthesis and nitrogen fixation were also located in both genomes. When strains PEPV15 and PEPV16 were inoculated in lettuce and carrot in field assays, we found that both significantly increased the yield of lettuce shoots and carrot roots by more than 20% and 10%, respectively. The results of this work confirmed that the genome mining of genes involved in plant colonization and growth promotion is a good strategy for predicting the potential of bacterial strains as crops inoculants, opening new horizons for the selection of bacterial strains with which to design new, effective bacteria-based plant biostimulants.

scholarly journals Antimicrobial Activity Screening of Rhizosphere Soil Bacteria from Tomato and Genome-Based Analysis of their Antimicrobial Biosynthetic Potential

2020 ◽  
Author(s):  
Lu Zhou ◽  
Chunxu Song ◽  
Zhibo Li ◽  
Oscar P. Kuipers
Keyword(s):  
Antimicrobial Activity ◽  
Plant Growth ◽  
Disease Control ◽  
Pseudomonas Syringae ◽  
Rhizosphere Soil ◽  
Gene Clusters ◽  
Bacterial Strains ◽  
Vast Number ◽  
Tomato Disease

Abstract Background: Tomato plant growth is frequently hampered by a high susceptibility to pests and diseases. Traditional chemical control causes a serious impact on both the environment and human health. Therefore, seeking environment-friendly and cost-effective green methods in agricultural production becomes crucial nowadays. Plant Growth Promoting Rhizobacteria (PGPR) can promote plant growth through biological activity. Their use is considered to be a promising sustainable approach for crop growth. Moreover, a vast number of biosynthetic gene clusters (BGCs) for secondary metabolite production are being revealed in PGPR, which helps to find potential anti-microbial activities for tomato disease control.Results: We isolated 351 bacterial strains (181 of which are Bacillus sp.) from healthy tomato, rhizosphere soil, and tomato tissues. In vitro antagonistic assays revealed that 34 Bacillus strains have antimicrobial activity against Erwinia carotovora, Pseudomonas syringae; Rhizoctonia solani; Botrytis cinerea; Verticillium dahliae and Phytophthora infestans. The genomes of 10 Bacillus and Paenibacillus strains with good antagonistic activity were sequenced. Via genome mining approaches, we identified 120 BGCs encoding NRPs, PKs-NRPs, PKs, terpenes and bacteriocins, including known compounds such as fengycin, surfactin, bacillibactin, subtilin, etc. In addition, several novel BGCs were identified. We discovered that the NRPs and PKs-NRPs BGCs in Bacillus species are encoding highly conserved known compounds as well as various novel variants.Conclusions: This study highlights the great number of varieties of BGCs in Bacillus strains. These findings pave the road for future usage of Bacillus strains as biocontrol agents for tomato disease control and are a resource arsenal for novel antimicrobial discovery.

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