-
Microbiology Resource Announcements Feb 2020Here, we report the draft genome sequence of the 3A-25AI strain, isolated from the rhizosphere of wild grass. This strain inhibits and phytopathogens. The genome size...
Here, we report the draft genome sequence of the 3A-25AI strain, isolated from the rhizosphere of wild grass. This strain inhibits and phytopathogens. The genome size is 5.6 Mb, with a G+C content of 45.59%, and contains 5,079 genes, 4,968 coding DNA sequences (CDSs), 35 tRNAs, 3 rRNAs, and 72 unexpected miscellaneous RNA (miscRNA) features.
PubMed: 32054710
DOI: 10.1128/MRA.01464-19 -
International Journal of Molecular... Oct 2019Cucumber is an important vegetable crop in China. Fusarium wilt is a soil-borne disease that can significantly reduce cucumber yields. WLY78 can strongly inhibit f....
Cucumber is an important vegetable crop in China. Fusarium wilt is a soil-borne disease that can significantly reduce cucumber yields. WLY78 can strongly inhibit f. sp. , which causes Fusarium wilt disease. In this study, we screened the genome of WLY78 and found eight potential antibiotic biosynthesis gene clusters. Mutation analysis showed that among the eight clusters, the fusaricidin synthesis () gene cluster is involved in inhibiting the genus, , , , , and . Further mutation analysis revealed that with the exception of , the seven genes , , , , , , and within the cluster were all involved in inhibiting fungi. This is the first time that demonstrated that was not essential. We first report the inhibitory mode of fusaricidin to inhibit spore germination and disrupt hyphal membranes. A biocontrol assay demonstrated that fusaricidin played a major role in controlling Fusarium wilt disease. Additionally, qRT-PCR demonstrated that fusaricidin could induce systemic resistance via salicylic acid (SA) signal against Fusarium wilt of cucumber. WLY78 is the first reported strain to both produce fusaricidin and fix nitrogen. Therefore, our results demonstrate that WLY78 will have great potential as a biocontrol agent in agriculture.
Topics: Antifungal Agents; Bacterial Proteins; Cucumis sativus; Depsipeptides; Disease Resistance; Fusarium; Paenibacillus polymyxa
PubMed: 31652608
DOI: 10.3390/ijms20205240 -
Microorganisms Jun 2022Maize ( L.) is an important crop in the world and maize sheath blight damages the yield and quality greatly. In this study, an antagonist strain, which exhibited...
Maize ( L.) is an important crop in the world and maize sheath blight damages the yield and quality greatly. In this study, an antagonist strain, which exhibited antagonism against pathogenic fungi of maize and controlled maize banded leaf sheath blight in the field, was effectively isolated and named strain SF05. High cellulase and chitinase activity of the strain were detected in this study, which might contribute to degrading the cell wall of fungi. Furthermore, different resistant genes such as , and were elicited differently by the strain in the leaves and stems of maize. In order to explain the biocontrol mechanism of strain SF05, the genome was sequenced and then the genes involving the biocontrol mechanism including biofilm formation pathways genes, cell wall degradation enzymes, secondary metabolite biosynthesis gene clusters and volatile organic compounds biosynthesis genes were predicted. The study revealed the biocontrol mechanism of strain SF05 preliminary and laid a foundation for further research of biocontrol mechanism of .
PubMed: 35889037
DOI: 10.3390/microorganisms10071318 -
Microbiology Resource Announcements Nov 2023Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as , while the remaining four were unique representatives of , , , and...
Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as , while the remaining four were unique representatives of , , , and sp., respectively. Each strain exhibited antagonistic activity against , underscoring their potential as sustainable agriculture resources.
PubMed: 37811974
DOI: 10.1128/MRA.00574-23 -
Future Microbiology May 2021Evaluate the chemopreventive potential of the extract from RNC-D. Concentrations of RNC-D extract were tested in HepG2/C3A cells to assess their genotoxic (comet...
Evaluate the chemopreventive potential of the extract from RNC-D. Concentrations of RNC-D extract were tested in HepG2/C3A cells to assess their genotoxic (comet assay), mutagenic (micronucleus test) and antigenotoxic potential (comet assay) . 400 and 40 μg/ml concentrations induced DNA lesions, whereas the 4 μg/ml induced a desmutagenic effect. Complementary tests indicated that the extract minimized the formation of reactive oxygen species induced by methyl methanesulfonate and normalized the loss of membrane potential. The quantification of cytokines indicated that TNF-α was immunostimulated by the extract. However, when administered in conjunction with the methyl methanesulfonate, the extract blocked the TNF-α release. The fermentation broth from RNC-D showed an antigenotoxic effect, and thus the potential to be used as chemopreventive compound.
Topics: Antimutagenic Agents; Cell Survival; Cytokines; Fermentation; Hep G2 Cells; Humans; Membrane Potential, Mitochondrial; Methyl Methanesulfonate; Mutagenicity Tests; Paenibacillus polymyxa; Reactive Oxygen Species
PubMed: 33960819
DOI: 10.2217/fmb-2020-0176 -
International Journal of Molecular... Apr 2021NifS and NifU (encoded by and ) are generally dedicated to biogenesis of the nitrogenase Fe-S cluster in diazotrophs. However, and are not found in N-fixing strains,...
NifS and NifU (encoded by and ) are generally dedicated to biogenesis of the nitrogenase Fe-S cluster in diazotrophs. However, and are not found in N-fixing strains, and the mechanisms involved in Fe-S cluster biosynthesis of nitrogenase is not clear. Here, we found that the genome of WLY78 contains the complete operon, a partial operon, a -like gene, two -like genes (-like and ), and two genes. Deletion and complementation studies showed that the , and genes of the operon, and -like and genes were involved in the Fe-S cluster biosynthesis of nitrogenase. Heterologous complementation studies demonstrated that the -like gene of WLY78 is interchangeable with , but WLY78 SufCDB cannot be functionally replaced by NifU. In addition, and are able to complement the WLY78 mutant. Our findings thus indicate that the NifS-like and SufCDB proteins are the specific sulfur donor and the molecular scaffold, respectively, for the Fe-S cluster formation of nitrogenase in WLY78. YutI can be an Fe-S cluster carrier involved in nitrogenase maturation in WLY78.
Topics: Bacterial Proteins; Genes, Bacterial; Iron-Sulfur Proteins; Nitrogenase; Paenibacillus polymyxa
PubMed: 33916504
DOI: 10.3390/ijms22073771 -
Frontiers in Microbiology 2022Pear Valsa canker caused by is among the most destructive diseases of pear, which causes significant economic loss. The present study was developed to explore the...
Pear Valsa canker caused by is among the most destructive diseases of pear, which causes significant economic loss. The present study was developed to explore the biocontrol efficiency and underlying antagonistic mechanism of strain Nl4 against . strain Nl4, one of the 120 different endophytic bacterial strains from pear branches, exhibited strong inhibitory effects against the mycelial growth of and caused hyphal malformation. Culture filtrate derived from strain Nl4 was able to effectively suppress mycelial growth of , and was found to exhibit strong protease, cellulase and β-1, 3-glucanase activity. Through re-isolation assay, strain Nl4 was confirmed to be capable of colonizing and surviving in pear branch. Treatment with strain NI4 effectively protected against pear Valsa canker symptoms on detached pear twigs inoculated with . Moreover, strain Nl4 promoted enhanced plant growth probably through the solubilization of phosphorus. Comparative transcriptomic analyses revealed that strain NI4 was able to suppress growth in large part through the regulation of the expression of membrane- and energy metabolism-related genes in this pathogen. Further transcriptomic analyses of pear trees indicated that strain NI4 inoculation was associated with changes in the expression of genes associated with secondary metabolite biosynthesis, signal transduction, and cutin, suberine, and wax biosynthesis. Together, these data highlighted strain Nl4 as a promising biocontrol agent against pear Valsa canker and investigated the possible mechanisms of strain Nl4 on control of this devastating disease.
PubMed: 35935238
DOI: 10.3389/fmicb.2022.950742 -
Frontiers in Microbiology 2022The multiple-sugar metabolism regulator (MsmR), a transcription factor belonging to the AraC/XylS family, participates in polysaccharide metabolism and virulence....
The multiple-sugar metabolism regulator (MsmR), a transcription factor belonging to the AraC/XylS family, participates in polysaccharide metabolism and virulence. However, the transcriptional regulatory mechanisms of MsmR1 in remain unclear. In this study, knocking out was found to reduce polymyxin synthesis by the SC2-M1 strain. Chromatin immunoprecipitation assay with sequencing (ChIP-seq) revealed that most enriched pathway was that of carbohydrate metabolism. Additionally, electromobility shift assays (EMSA) confirmed the direct interaction between MsmR1 and the promoter regions of , , , , , , , and . MsmR1 stimulates polymyxin biosynthesis by directly binding to the promoter regions of and , while also directly regulating and influencing the citrate cycle (TCA cycle). In addition, MsmR1 directly activates and was beneficial for spore and biofilm formation. These results indicated that MsmR1 could regulate carbohydrate and amino acid metabolism, and indirectly affect biological processes such as polymyxin synthesis, biofilm formation, and motility. Moreover, MsmR1 could be autoregulated. Hence, this study expand the current knowledge of MsmR1 and will be beneficial for the application of SC2 in the biological control against the certain pathogens in pepper.
PubMed: 36483206
DOI: 10.3389/fmicb.2022.1039806 -
Applied and Environmental Microbiology Jun 2022Despite being unicellular organisms, bacteria undergo complex regulation mechanisms which coordinate different physiological traits. Among others, DegU, DegS, and Spo0A...
Despite being unicellular organisms, bacteria undergo complex regulation mechanisms which coordinate different physiological traits. Among others, DegU, DegS, and Spo0A are the pleiotropic proteins which govern various cellular responses and behaviors. However, the functions and regulatory networks between these three proteins are rarely described in the highly interesting bacterium Paenibacillus polymyxa. In this study, we investigate the roles of DegU, DegS, and Spo0A by introduction of targeted point mutations facilitated by a CRISPR-Cas9-based system. In total, five different mutant strains were generated, the single mutants DegU Q218*, DegS L99F, and Spo0A A257V, the double mutant DegU Q218* DegS L99F, and the triple mutant DegU Q218* DegS L99F Spo0A A257V. Characterization of the wild-type and the engineered strains revealed differences in swarming behavior, conjugation efficiency, sporulation, and viscosity formation of the culture broth. In particular, the double mutant DegU Q218* DegS L99F showed a significant increase in conjugation efficiency as well as a stable exopolysaccharides formation. Furthermore, we highlight similarities and differences in the roles of DegU, DegS, and Spo0A between P. polymyxa and related species. Finally, this study provides novel insights into the complex regulatory system of P. polymyxa DSM 365. To date, only limited knowledge is available on how complex cellular behaviors are regulated in P. polymyxa. In this study, we investigate several regulatory proteins which play a role in governing different physiological traits. Precise targeted point mutations were introduced to their respective genes by employing a highly efficient CRISPR-Cas9-based system. Characterization of the strains revealed some similarities, but also differences, to the model bacterium Bacillus subtilis with regard to the regulation of cellular behaviors. Furthermore, we identified several strains which have superior performance over the wild-type. The applicability of the CRISPR-Cas9 system as a robust genome editing tool, in combination with the engineered strain with increased genetic accessibility, would boost further research in P. polymyxa and support its utilization for biotechnological applications. Overall, our study provides novel insights, which will be of importance in understanding how multiple cellular processes are regulated in species.
Topics: Bacillus subtilis; Bacterial Proteins; CRISPR-Cas Systems; Paenibacillus polymyxa; Point Mutation
PubMed: 35588272
DOI: 10.1128/aem.00164-22 -
Journal of the Science of Food and... Mar 2021Fusarium head blight (FHB) is one of the disasters that seriously harm wheat and other small grain crops. It causes spoilage and mildew of the grain leading to a...
BACKGROUND
Fusarium head blight (FHB) is one of the disasters that seriously harm wheat and other small grain crops. It causes spoilage and mildew of the grain leading to a significant decline in the yield and quality of the grain. This research aimed to isolate antagonistic bacteria to purify antifungal proteins. A strain was isolated from the rhizosphere of healthy wheat in a wheat field affected by a severe FHB epidemic. This isolated strain was tentatively identified as Paenibacillus polymyxa 7F1, which displayed a strong inhibitory effect against several other pathogens. One novel antifungal protein was purified from the P. polymyxa 7F1 and successfully expressed.
RESULTS
A crude culture of P. polymyxa 7F1 demonstrated antifungal activity that was stable at a temperature range of 60-90 °C and a pH range of 2.6-9.0. However, the antifungal activity of the P. polymyxa 7F1 was inhibited with proteinase K, trypsin, and neutral protease treatment. A 36 kDa protein with broad-spectrum antifungal activity was purified from the P. polymyxa 7F1. A glycosyl hydrolase domain was identified from this protein through liquid chromatography-mass spectrometry (LC-MS) analysis. A recombinant plasmid pET32a(+)/36kd for prokaryotic expression was constructed, and the renatured p36kd protein demonstrated similar antifungal activity to the 36 kDa protein purified from the P. polymyxa 7F1.
CONCLUSION
A novel antifungal protein produced by P. polymyxa 7F1 was purified and expressed. The recombinant protein showed good antifungal activity as the novel purified protein. The novel antifungal protein provides an effective way to control the Fusarium head blight. © 2020 Society of Chemical Industry.
Topics: Fungicides, Industrial; Fusarium; Paenibacillus polymyxa; Plant Diseases; Rhizosphere; Soil Microbiology; Triticum
PubMed: 32895910
DOI: 10.1002/jsfa.10805