scholarly journals A plant endophyte Staphylococcus hominis strain MBL_AB63 produces a novel lantibiotic, homicorcin and a position one variant

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Aftab Uddin ◽  
Shammi Akter ◽  
Mahbuba Ferdous ◽  
Badrul Haidar ◽  
Al Amin ◽  
...  
Keyword(s):  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Whole Genome Sequence ◽  
Antimicrobial Substances ◽  
The Core ◽  
Rp Hplc ◽  
Ring Structures ◽  
Core Peptide ◽  
Staphylococcus Hominis ◽  
Epilancin 15X

AbstractHere we report a jute endophyte Staphylococcus hominis strain MBL_AB63 isolated from jute seeds which showed promising antimicrobial activity against Staphylococcus aureus SG511 when screening for antimicrobial substances. The whole genome sequence of this strain, annotated using BAGEL4 and antiSMASH 5.0 to predict the gene clusters for antimicrobial substances identified a novel antimicrobial peptide cluster that belongs to the class I lantibiotic group. The predicted lantibiotic (homicorcin) was found to be 82% similar to a reported peptide epicidin 280 having a difference of seven amino acids at several positions of the core peptide. Two distinct peaks obtained at close retention times from a RP-HPLC purified fraction have comparable antimicrobial activities and LC–MS revealed the molecular mass of these peaks to be 3046.5 and 3043.2 Da. The presence of an oxidoreductase (homO) similar to that of epicidin 280- associated eciO or epilancin 15X- associated elxO in the homicorcin gene cluster is predicted to be responsible for the reduction of the first dehydrated residue dehydroalanine (Dha) to 2-hydroxypropionate that causes an increase of 3 Da mass of homicorcin 1. Trypsin digestion of the core peptide and its variant followed by ESI–MS analysis suggests the presence of three ring structures, one in the N-terminal and other two interlocking rings at the C-terminal region that remain undigested. Homicorcin exerts bactericidal activity against susceptible cells by disrupting the integrity of the cytoplasmic membrane through pore formation as observed under FE-SEM.

scholarly journals Biocontrol of tomato bacterial wilt by the new strain Bacillus velezensis FJAT-46737 and its lipopeptides

2020 ◽  
Author(s):  
Meichun Chen ◽  
Jieping Wang ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Rongfeng Xiao ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Plant Pathogens ◽  
Nitrogen Sources ◽  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Biocontrol Agents ◽  
Whole Genome Sequence ◽  
The Rich ◽  
Tomato Bacterial Wilt

Abstract Background: There is an urgent need to discover biological biocontrol agents to control bacterial wilt. This study reports on a new lipopeptide-producing biocontrol strain FJAT-46737 and explores its lipopeptidic compounds, and this study investigates the antagonistic effects of these compounds.Results: Based on a whole genome sequence analysis, the new strain FJAT-46737 was identified as Bacillus velezensis, and seven gene clusters responsible for the synthesis of bioactive secondary metabolites in FJAT-46737 were predicted. The antimicrobial results demonstrated that FJAT-46737 exhibited broad-spectrum antimicrobial activities in vitro against three bacteria and three fungi. Pot experiments showed that the control efficiencies for tomato bacterial wilt of the whole cultures, the 2-fold diluted supernatants and the crude lipopeptide of FJAT-46737 were 66.2%, 82.0%, and 96.2%, respectively. The above results suggested that one of the antagonistic mechanisms of FJAT-46737 was the secretion of lipopeptides consisting of iturins, fengycins and surfactins. The crude lipopeptides had significant antagonistic activities against several pathogens (including Ralstonia solanacearum, Escherichia coli and Fusarium oxysporum) and fengycins were the major antibacterial components of the lipopeptides against R. solanacearum in vitro. Furthermore, the rich organic nitrogen sources (especially yeast extracts) in the media promoted the production of fengycin and surfactin by FJAT-46737. The secretion of these two lipopeptides was related to temperature fluctuations, with the fengycin content decreasing by 96.6% and the surfactins content increasing by 59.9% from 20 oC to 40 oC. The optimal temperature for lipopeptide production by FJAT-46737 varied between 20 oC and 25oC. Conclusions: The B. velezensis strain FJAT-46737 and its secreted lipopeptides could be used as new sources of potential biocontrol agents against several plant pathogens, and especially the bacterial wilt pathogen R. solanacearum.

Mutagenesis of precursor peptide for the generation of nosiheptide analogues

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94643-94650 ◽  
Author(s):  
Shuzhen Wang ◽  
Xulu Zheng ◽  
Qi Pan ◽  
Yijun Chen
Keyword(s):  
Antimicrobial Activities ◽  
The Core ◽  
Precursor Peptide ◽  
Core Peptide

Thr3 in the core peptide of NosM could be mutated to generate nosiheptide analogues retaining antimicrobial activities.

scholarly journals Biocontrol of tomato bacterial wilt by a new strain Bacillus velezensis FJAT-46737 and its lipopeptides

2019 ◽  
Author(s):  
Meichun Chen ◽  
Jieping Wang ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Rongfeng Xiao ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Plant Pathogens ◽  
Antimicrobial Agents ◽  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Whole Genome Sequence ◽  
Dependent Manner ◽  
Bacillus Velezensis ◽  
Tomato Bacterial Wilt

Abstract Background There is an urgent need to discover alternative antimicrobial agents to control bacterial wilt. The objectives of this study were to report a new lipopeptide-producding biocontrol strain FJAT-46737 and its lipopeptides, and to investigate their antagonistic effects.Results Based on the whole genome sequence analysis, the new strain FJAT-46737 was finally identified as Bacillus velezensis and seven gene clusters that responsible for synthesis of bioactive secondary metabolite in the FJAT-46737 were predicted. Antimicrobial results demonstrated that FJAT-46737 exhibited broad-spectrum antimicrobial activities in vitro against bacteria and fungi. The pot experiments showed that the tomato bacterial wilt control efficiencies of the whole cultures, the 2-fold diluted supernatants and the crude lipopeptide of FJAT-46737 were 66.2%, 82.0%, and 96.2%, respectively. The above results suggested that one of the antagonistic mechanisms of FJAT-46737 was secretion of lipopeptides that consisted of iturins, fengycins and surfactins. The crude lipopeptides had significant antagonistic activities on several pathogen in a dosage-dependent manner, and the fengycins confirmed to play a major role in antibacterial abilities in vitro of the lipopeptides against Ralstonia solanacearum . Furthermore, it was found that the rich organic nitrogen sources (expecially yeast extracts) in the media were benificial for FJAT-46737 to produce fengycin and surfactin. The secretion of these two lipopeptides were also adjusted by the culture temperature: the content of the fengycins decreased by 96.6% and that of the surfactins ascended by 59.9% from 20 o C to 40 o C. And 20 o C~25 o C is the suitable temperature for FJAT-46737 to produce lipopeptide.Conclusions The B. velezensis strain FJAT-46737 and its lipopeptides would used as new sources of potential biocontrol agents against plant pathogens, especially the bacterial wilt pathogen R. solanacearum .

scholarly journals Biocontrol of tomato bacterial wilt by the new strain Bacillus velezensis FJAT-46737 and its lipopeptides

2020 ◽  
Author(s):  
Meichun Chen ◽  
Jieping Wang ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Rongfeng Xiao ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Plant Pathogens ◽  
Nitrogen Sources ◽  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Biocontrol Agents ◽  
Whole Genome Sequence ◽  
The Rich ◽  
Tomato Bacterial Wilt

Abstract Background: There is an urgent need to discover alternative Bacillus biocontrol agents to control bacterial wilt. This study reports on a new lipopeptide-producing biocontrol strain FJAT-46737 and explores its lipopeptidic compounds, and this study investigates the antagonistic effects of these compounds.Results: Based on a whole genome sequence analysis, the new strain FJAT-46737 was identified as Bacillus velezensis, and seven gene clusters responsible for the synthesis of bioactive secondary metabolites in FJAT-46737 were predicted. The antimicrobial results demonstrated that FJAT-46737 exhibited broad-spectrum antimicrobial activities in vitro against three bacteria and three fungi. Pot experiments showed that the control efficiencies for tomato bacterial wilt of the whole cultures, the 2-fold diluted supernatants and the crude lipopeptide of FJAT-46737 were 66.2%, 82.0%, and 96.2%, respectively. The above results suggested that one of the antagonistic mechanisms of FJAT-46737 was the secretion of lipopeptides consisting of iturins, fengycins and surfactins. The crude lipopeptides had significant antagonistic activities against several pathogens (including Ralstonia solanacearum, Escherichia coli and Fusarium oxysporum) and fengycins were the major antibacterial components of the lipopeptides against R. solanacearum in vitro. Furthermore, the rich organic nitrogen sources (especially yeast extracts) in the media promoted the production of fengycin and surfactin by FJAT-46737. The secretion of these two lipopeptides was related to temperature fluctuations, with the fengycin content decreasing by 96.6% and the surfactins content increasing by 59.9% from 20 oC to 40 oC. The optimal temperature for lipopeptide production by FJAT-46737 varied between 20 oC and 25oC. Conclusions: The B. velezensis strain FJAT-46737 and its secreted lipopeptides could be used as new sources of potential biocontrol agents against several plant pathogens, and especially the bacterial wilt pathogen R. solanacearum.

scholarly journals Biocontrol of tomato bacterial wilt by a new strain Bacillus velezensis FJAT-46737 and its lipopeptides

2019 ◽  
Author(s):  
Meichun Chen ◽  
Jieping Wang ◽  
Bo Liu ◽  
Yujing Zhu ◽  
Rongfeng Xiao ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Plant Pathogens ◽  
Antimicrobial Agents ◽  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Whole Genome Sequence ◽  
Dependent Manner ◽  
Bacillus Velezensis ◽  
Tomato Bacterial Wilt

Abstract Background: There is an urgent need to discover alternative antimicrobial agents to control bacterial wilt. The objectives of this study were to report a new lipopeptide-producing biocontrol strain FJAT-46737 and its lipopeptides, and to investigate their antagonistic effects. Results: Based on the whole genome sequence analysis, the new strain FJAT-46737 was finally identified as Bacillus velezensis and seven gene clusters that responsible for synthesis of bioactive secondary metabolite in the FJAT-46737 were predicted. Antimicrobial results demonstrated that FJAT-46737 exhibited broad-spectrum antimicrobial activities in vitro against bacteria and fungi . The pot experiments showed that the tomato bacterial wilt control efficiencies of the whole cultures, the 2-fold diluted supernatants and the crude lipopeptide of FJAT-46737 were 66.2%, 82.0%, and 96.2%, respectively. The above results suggested that one of the antagonistic mechanisms of FJAT-46737 was secretion of lipopeptides that consisted of iturins, fengycins and surfactins. The crude lipopeptides had significant antagonistic activities on several pathogen in a dosage-dependent manner, and the fengycins confirmed to play a major role in antibacterial abilities in vitro of the lipopeptides against Ralstonia solanacearum . Furthermore, it was found that the rich organic nitrogen sources (especially yeast extracts) in the media were beneficial for FJAT-46737 to produce fengycin and surfactin. The secretion of these two lipopeptides were also adjusted by the culture temperature: the content of the fengycins decreased by 96.6% and that of the surfactins ascended by 59.9% from 20 o C to 40 o C. The temperature of 20 o C~25 o C is the suitable temperature for FJAT-46737 to produce lipopeptide. Conclusions: The B. velezensis strain FJAT-46737 and its lipopeptides would used as new sources of potential biocontrol agents against plant pathogens, especially the bacterial wilt pathogen R. solanacearum .

scholarly journals Biocontrol of tomato bacterial wilt by the new strain Bacillus velezensis FJAT-46737 and its lipopeptides

2020 ◽  
Author(s):  
Meichun Chen ◽  
Jieping Wang(New Corresponding Author) ◽  
Bo Liu(Former Corresponding Author) ◽  
Yujing Zhu ◽  
Rongfeng Xiao ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Plant Pathogens ◽  
Antimicrobial Agents ◽  
Nitrogen Sources ◽  
Gene Clusters ◽  
Antimicrobial Activities ◽  
Whole Genome Sequence ◽  
Bacillus Velezensis ◽  
Tomato Bacterial Wilt

Abstract Background: There is an urgent need to discover alternative antimicrobial agents to control bacterial wilt. This study reports on a new lipopeptide-producing biocontrol strain FJAT-46737 and explores its lipopeptidic compounds, and this study investigates the antagonistic effects of these compounds. Results: Based on a whole genome sequence analysis, the new strain FJAT-46737 was identified as Bacillus velezensis, and seven gene clusters responsible for the synthesis of bioactive secondary metabolites in FJAT-46737 were predicted. The antimicrobial results demonstrated that FJAT-46737 exhibited broad-spectrum antimicrobial activities in vitro against three bacteria and three fungi. Pot experiments showed that the control efficiencies for tomato bacterial wilt of the whole cultures, the 2-fold diluted supernatants and the crude lipopeptide of FJAT-46737 were 66.2%, 82.0%, and 96.2%, respectively. The above results suggested that one of the antagonistic mechanisms of FJAT-46737 was the secretion of lipopeptides consisting of iturins, fengycins and surfactins. The crude lipopeptides had significant antagonistic activities against several pathogens (including Ralstonia solanacearum, Escherichia coli and Fusarium oxysporum) and fengycins were the major antibacterial components of the lipopeptides against R. solanacearum in vitro. Furthermore, the rich organic nitrogen sources (especially yeast extracts) in the media promoted the production of fengycin and surfactin by FJAT-46737. The secretion of these two lipopeptides was related to temperature fluctuations, with the fengycin content decreasing by 96.6% and the surfactins content increasing by 59.9% from 20 oC to 40 oC. The optimal temperature for lipopeptide production by FJAT-46737 varied between 20 oC and 25oC. Conclusions: The B. velezensis strain FJAT-46737 and its lipopeptides represent new sources of potential biocontrol agents against plant pathogens, especially the bacterial wilt pathogen R. solanacearum.

scholarly journals Highlighting the Biotechnological Potential of Deep Oceanic Crust Fungi through the Prism of Their Antimicrobial Activity

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Oceanic Crust ◽  
Gene Clusters ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Human Pathogens ◽  
Biotechnological Potential ◽  
Fungal Isolates

Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.

scholarly journals DEVELOPMENT OF IN VITRO METHODOLOGIES FOR INHIBITION OF PATHOGENIC BACTERIA BY POTENTIAL PROBIOTIC LACTOBACILLUS SPS; AN EVIDENCE FOR PRODUCTION OF ANTIMICROBIAL SUBSTANCES

2016 ◽  
Vol 8 (12) ◽  
pp. 277
Author(s):  
Prabhurajeshwar C. ◽  
Kelmani Chandrakanth R.
Keyword(s):  
Bile Salts ◽  
Pathogenic Bacteria ◽  
Antimicrobial Activities ◽  
Local Market ◽  
Preliminary Screening ◽  
Milk Products ◽  
Antimicrobial Substances ◽  
Live Bacteria ◽  
Digestive Health

<p><strong>Objective: </strong>Probiotic products consist of specific strains of live bacteria that have potentially favorable health effects. A number of studies provide evidence that milk products with probiotics may be beneficial for digestive health and may improve various digestive problems. The purpose of the present study was to investigate <em>Lactobacillus</em> species with potential activities isolated from different cheese samples of local market.</p><p><strong>Methods: </strong>A total 42 lactic acid bacteria strains were isolated, fourteen (14/42) best <em>Lactobacillus</em> isolates were selected by preliminary screening as potential probiotics with antimicrobial activity against pathogenic bacteria. All the fourteen <em>Lactobacillus</em> isolates were then characterized <em>in vitro</em> for their probiotic features and antimicrobial activities against pathogens.</p><p><strong>Results: </strong>The results noticed that all selected <em>Lactobacillus</em> isolates (CH3, CH4 and CH6) were screened and confirmed as <em>Lactobacillus. </em>The isolates were able to grow at different pH, NaCl and bile salts, also exhibited the best antimicrobial activities against pathogens. All the isolates were susceptible to antibiotics used and isolates were also revealed the noticeable aggregation and hydrophobicity studies.<strong></strong></p><p><strong>Conclusion: </strong>Selected <em>Lactobacillus </em>isolates were considered as ideal, effective probiotic bacteria. Thus, they could be examined further and contribute to preventing and controlling several infections associated with intestine and for human health benefits.</p>

scholarly journals Whole-Genome Sequencing Reveals a New Genospecies ofMethylobacteriumsp. GXS13, Isolated fromVitis viniferaL. Xylem Sap

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Wan Xin Lai ◽  
Han Ming Gan ◽  
André O. Hudson ◽  
Michael A. Savka
Keyword(s):  
Xylem Sap ◽  
Gene Clusters ◽  
Homoserine Lactone ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
Acyl Homoserine Lactone ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Cell Wall Modification ◽  
Cytokinin Synthesis

The whole-genome sequence of a new genospecies ofMethylobacteriumsp., named GXS13 and isolated from grapevine xylem sap, is reported and demonstrates potential for methylotrophy, cytokinin synthesis, and cell wall modification. In addition, biosynthetic gene clusters were identified for cupriachelin, carotenoid, and acyl-homoserine lactone using the antiSMASH server.

scholarly journals FoxP3 associates with enhancer-promoter loops to regulate Treg-specific gene expression

2021 ◽  
Author(s):  
Ricardo N Ramirez ◽  
Kaitavjeet Chowdhary ◽  
Juliette Leon ◽  
Diane Mathis ◽  
Christophe Benoist
Keyword(s):  
Gene Expression ◽  
Chromatin Immunoprecipitation ◽  
T Regulatory Cells ◽  
Gene Clusters ◽  
Specific Gene ◽  
Regulatory Cells ◽  
Proximity Ligation ◽  
The Core ◽  
Transcriptional Cofactors ◽  
Number Of Genes

Gene expression programs are specified by higher-order chromatin structure and enhancer-promoter loops (EPL). T regulatory cells (Treg) identity is dominantly specified by the transcription factor FoxP3, whose mechanism of action is unclear. We applied proximity-ligation with chromatin immunoprecipitation (HiChIP) in Treg and closely related conventional CD4+ T cells (Tconv). EPL identified by H3K27Ac HiChIP showed a range of connection intensity, with some super-connected genes. TF-specific HiChIP showed that FoxP3 interacts with EPLs at a large number of genes, including some not differentially expressed in Treg vs Tconv, but enriched at the core Treg signature loci that it upregulates. FoxP3 association correlates with heightened H3H27Ac looping, as ascertained by analysis of FoxP3-deficient Treg-like cells. There was marked asymmetry in the loci where FoxP3 associated at the enhancer- or the promoter-side of EPLs, with enrichment for different transcriptional cofactors. FoxP3 EPL intensity distinguished gene clusters identified by single-cell ATAC-seq as co-varying between individual Tregs, supporting a direct transactivation model for FoxP3 in determining Treg identity.

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