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Functional Plant Biology : FPB Jun 2023Bacteria that enhance plant growth and development and are found in the vicinity of roots are referred to as plant growth-promoting rhizobacteria. Some beneficial...
Bacteria that enhance plant growth and development and are found in the vicinity of roots are referred to as plant growth-promoting rhizobacteria. Some beneficial bacteria help plant tolerance to many hazardous chemical elements. In this context, Cupriavidus basilensis , Novosphingobium humi , Bacillus zanthoxyli , Bacillus sp., Paenibacillus alvei , Ancylobacter aquaticus and Ralstonia syzygii metal-tolerant rhizospheric bacteria were isolated from rhizospheric soil associated with Bacopa monnieri . The beneficial effects of rhizospheric bacteria on B. monnieri plant physiology and biochemical responses were investigated under pot conditions at two levels (100μM and 500μM) of CuSO4 or FeCl3 . N. humi , A. aquaticus and R. syzygii bacterial strains were associated with significantly increased height and biomass under normal and stress conditions. An assay for indole acetic acid in isolated rhizospheric bacteria found differential secretion except Bacillus zanthoxyli . Bacoside A is a major phytocompound in B. monnieri with medicinal value; maximum induction was observed in the R. syzygii treatment. High concentration of copper and iron salts negatively influenced height, biomass and photosynthetic pigments; however N. humi , A. aquaticus , Bacilllus sp. and R. syzygii beneficial bacterial helped plants under stress conditions. Moreover, a significant enhancement in chlorophyll a and b was noticed in C. basilensis , B. zanthoxyli , Bacilllus sp., P. alvei and R. syzygii treatments, without much influence on carotenoid levels. Therefore, the present study emphasises the importance of isolating plant growth-promoting rhizobacteria for use in bacopa plants exposed to metals such as copper and iron in soil.
Topics: Copper; Iron; Bacopa; Chlorophyll A; Bacteria; Gallionellaceae; Soil
PubMed: 37045602
DOI: 10.1071/FP22263 -
Frontiers in Plant Science 2021The sustainable development of agriculture can be stimulated by the great market availability of bio-inputs, including phosphate-solubilizing microbial strains. However,...
The sustainable development of agriculture can be stimulated by the great market availability of bio-inputs, including phosphate-solubilizing microbial strains. However, these strains are currently selected using imprecise and questionable solubilization methodologies in solid or liquid media. We hypothesized that the hydroponic system could be a more efficient methodology for selecting phosphate-solubilizing strains as plant growth promoters. This methodology was tested using the plant as a model. The growth-promoting potential of the strains was compared with that of the Biomaphos® commercial microbial mixture. The obtained calcium phosphate (CaHPO) solubilization results using the hydroponic system were inconsistent with those observed in solid and liquid media. However, the tests in liquid medium demonstrated poor performances of sp. (328EF) and (33EF) in reducing pH and solubilizing CaHPO, which corroborates with the effects of biotic stress observed in plants inoculated with these strains. Nevertheless, the hydroponic system allowed the characterization of (PA12), which is also efficient in solubilization in a liquid medium. The bacterium (PA26) was the most effective in CaHPO solubilization owing to the higher phosphorus (P) absorption, growth promotion, and physiological performance observed in plants inoculated with this bacterium. The hydroponic method proved to be superior in selecting solubilizing strains, allowing the assessment of multiple patterns, such as nutritional level, growth, photosynthetic performance, and anatomical variation in plants, and even the detection of biotic stress responses to inoculation, obtaining strains with higher growth promotion potential than Biomaphos®. This study proposed a new approach to confirm the solubilizing activity of microorganisms previously selected and potentially intended for the bio-input market that are useful in P availability for important crops, such as soybeans.
PubMed: 34777440
DOI: 10.3389/fpls.2021.759463 -
Chemical Biology & Drug Design May 2015AN5-1 (YSKSLPLSVLNP) is an antimicrobial peptide isolated from the fermentation broth of Paenibacillus alvei strain AN5 (J Ind Microb Biotechnol 2013; 40: 571-9). In...
AN5-1 (YSKSLPLSVLNP) is an antimicrobial peptide isolated from the fermentation broth of Paenibacillus alvei strain AN5 (J Ind Microb Biotechnol 2013; 40: 571-9). In this study, we report the application of ubiquitin fusion technology to the expression and purification of AN5-1. Minimum inhibitory concentration (MIC) and measurement of hemolytic activity (MHC) were measured to confirm the biological activities of the expressed AN5-1. Bacterial cell membrane permeabilization was investigated to show the interaction between the AN5-1 and the bacterial cytoplasmic membrane. Furthermore, intracellular activities of the AN5-1 were determined by genomic DNA interaction assays. The results revealed AN5-1 damaging bacterial membranes and binding to bacterial genomic DNA to inhibit cellular functions, suggesting that it has multiple intracellular targets in bacteria. The application of ubiquitin fusion technology may be an excellent approach for industrial production to the expression and purification of antimicrobial peptide. Furthermore, AN5-1 was demonstrated as an antimicrobial peptide with great potentials, as bacterial resistance to AN5-1 would be not expected, due to the dual mechanisms of AN5-1 against bacteria.
Topics: Amino Acid Sequence; Anti-Infective Agents; Antimicrobial Cationic Peptides; Bacteria; Cell Wall; Circular Dichroism; DNA; Erythrocytes; Escherichia coli; Hemolysis; Humans; Microbial Sensitivity Tests; Paenibacillus; Protein Binding; Protein Structure, Secondary; Recombinant Fusion Proteins; Spectrometry, Fluorescence
PubMed: 25311453
DOI: 10.1111/cbdd.12449 -
Frontiers in Microbiology 2018Various mechanisms of protein cell surface display have evolved during bacterial evolution. Several Gram-positive bacteria employ S-layer homology (SLH) domain-mediated...
Various mechanisms of protein cell surface display have evolved during bacterial evolution. Several Gram-positive bacteria employ S-layer homology (SLH) domain-mediated sorting of cell-surface proteins and concomitantly engage a pyruvylated secondary cell-wall polymer as a cell-wall ligand. Specifically, pyruvate ketal linked to β-D-ManNAc is regarded as an indispensable epitope in this cell-surface display mechanism. That secondary cell wall polymer (SCWP) pyruvylation and SLH domain-containing proteins are functionally coupled is supported by the presence of an ortholog of the predicted pyruvyltransferase CsaB in bacterial genomes, such as those of and . The SCWP, consisting of pyruvylated disaccharide repeats [→4)-β-D-GlcNAc-(1→3)-4,6-Pyr-β-D-ManNAc-(1→] serves as a model to investigate the widely unexplored pyruvylation reaction. Here, we reconstituted the underlying enzymatic pathway in combination with synthesized compounds, used mass spectrometry, and nuclear magnetic resonance spectroscopy for product characterization, and found that CsaB-catalyzed pyruvylation of β-D-ManNAc occurs at the stage of the lipid-linked repeat. We produced the TagA (PAV_RS07420) and CsaB (PAV_RS07425) enzymes as recombinant, tagged proteins, and using a synthetic 11-phenoxyundecyl-diphosphoryl-α-GlcNAc acceptor, we uncovered that TagA is an inverting UDP-α-D-ManNAc:GlcNAc-lipid carrier transferase, and that CsaB is a pyruvyltransferase, with synthetic UDP-α-D-ManNAc and phosphoenolpyruvate serving as donor substrates. Next, to substitute for the UDP-α-D-ManNAc substrate, the recombinant UDP-GlcNAc-2-epimerase MnaA (PAV_RS07610) of was included in this reconstitution system. When all three enzymes, their substrates and the lipid-linked GlcNAc primer were combined in a one-pot reaction, a lipid-linked SCWP repeat precursor analog was obtained. This work highlights the biochemical basis of SCWP biosynthesis and bacterial pyruvyl transfer.
PubMed: 29997588
DOI: 10.3389/fmicb.2018.01356 -
Metabolites May 2020Plant growth-promoting rhizobacteria (PGPR) are beneficial microbes in the rhizosphere that can directly or indirectly stimulate plant growth. In addition, some can...
Plant growth-promoting rhizobacteria (PGPR) are beneficial microbes in the rhizosphere that can directly or indirectly stimulate plant growth. In addition, some can prime plants for enhanced defense against a broad range of pathogens and insect herbivores. In this study, four PGPR strains ( N04, N19, T19, and T22) were used to induce priming in (cv. Moneymaker) plants. Plants were inoculated with each of the four PGPRs, and plant tissues (roots, stems, and leaves) were harvested at 24 h and 48 h post-inoculation. Methanol-extracted metabolites were analyzed by ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). Chemometric methods were applied to mine the data and characterize the differential metabolic profiles induced by the PGPR. The results revealed that all four strains induced defense-related metabolic reprogramming in the plants, characterized by dynamic changes to the metabolomes involving hydroxycinnamates, benzoates, flavonoids, and glycoalkaloids. In addition, targeted analysis of aromatic amino acids indicated differential quantitative increases or decreases over a two-day period in response to the four PGPR strains. The metabolic alterations point to an altered or preconditioned state that renders the plants primed for enhanced defense responses. The results contribute to ongoing efforts in investigating and unraveling the biochemical processes that define the PGPR priming phenomenon.
PubMed: 32443694
DOI: 10.3390/metabo10050210 -
Archives of Microbiology May 2015Colistin is a mixture of polymyxin E1 and E2, bactericidal pentacationic lipopeptides used to treat infections caused by Gram-negative pathogens such as Pseudomonas...
Colistin is a mixture of polymyxin E1 and E2, bactericidal pentacationic lipopeptides used to treat infections caused by Gram-negative pathogens such as Pseudomonas aeruginosa and Klebsiella pneumoniae. Industrial production of colistin is obtained by a fermentation process of the natural producer Paenibacillus polymyxa var colistinus. NonRibosomal peptide synthetases (NRPS) coding the biosynthesis of polymyxins A, B and P have been recently described, rendering thereof the improvement of their production possible. However, the colistin biosynthesis pathway was not published so far. In this study, a Paenibacillus alvei has been identified by biochemical (Api 50 CH system) and molecular (16S rDNA sequencing) methods. Its culture supernatant displayed inhibitory activity against Gram-negative bacteria (P. aeruginosa, K. pneumoniae, Salmonella spp.). Two polymyxins, E1 and E2, were recovered from the supernatant and were characterized by high resolution LC-MS. A genomic library (960 clones) was constructed to identify the gene cluster responsible for biosynthesis of polymyxins. Selection of the clones harbouring the sequences of interest was obtained by a simple PCR-based screening. We used primers targeting NRPS sequences leading to the incorporation of amino acids present in polymyxins E. The sequences from three clones of interest were assembled on 50.4 kb. Thus, five open reading frames corresponding to a new NRPS gene cluster of 41 kb were identified. In silico, analyses revealed the presence of three NRPS implicated in the biosynthesis of polymyxins E. This work provides insightful information on colistin biosynthesis and might contribute to future drug developments in this group of antibiotics.
Topics: Anti-Bacterial Agents; Base Sequence; Colistin; DNA, Bacterial; Microbial Sensitivity Tests; Multigene Family; Paenibacillus; Peptide Synthases; Pseudomonas aeruginosa; Sequence Analysis, DNA; Tandem Mass Spectrometry
PubMed: 25609230
DOI: 10.1007/s00203-015-1084-5 -
The Journal of Biological Chemistry Jul 2018Pro-Pro endopeptidases (PPEPs) belong to a recently discovered family of proteases capable of hydrolyzing a Pro-Pro bond. The first member from the bacterial pathogen...
Pro-Pro endopeptidases (PPEPs) belong to a recently discovered family of proteases capable of hydrolyzing a Pro-Pro bond. The first member from the bacterial pathogen (PPEP-1) cleaves two cell-surface proteins involved in adhesion, one of which is encoded by the gene adjacent to the gene. However, related PPEPs may exist in other bacteria and may shed light on substrate specificity in this enzyme family. Here, we report on the homolog of PPEP-1 in , which we denoted PPEP-2. We found that PPEP-2 is a secreted metalloprotease, which likewise cleaved a cell-surface protein encoded by an adjacent gene. However, the cleavage motif of PPEP-2, PLP↓PVP, is distinct from that of PPEP-1 (VNP↓PVP). As a result, an optimal substrate peptide for PPEP-2 was not cleaved by PPEP-1 and vice versa. To gain insight into the specificity mechanism of PPEP-2, we determined its crystal structure at 1.75 Å resolution and further confirmed the structure in solution using small-angle X-ray scattering (SAXS). We show that a four-amino-acid loop, which is distinct in PPEP-1 and -2 (GGST in PPEP-1 and SERV in PPEP-2), plays a crucial role in substrate specificity. A PPEP-2 variant, in which the four loop residues had been swapped for those from PPEP-1, displayed a shift in substrate specificity toward PPEP-1 substrates. Our results provide detailed insights into the PPEP-2 structure and the structural determinants of substrate specificity in this new family of PPEP proteases.
Topics: Amino Acid Sequence; Bacterial Proteins; Crystallography, X-Ray; Dipeptides; Endopeptidases; Models, Molecular; Paenibacillus; Protein Conformation; Sequence Homology; Substrate Specificity
PubMed: 29794027
DOI: 10.1074/jbc.RA118.003244 -
MicrobiologyOpen Mar 2019European foulbrood is a globally distributed brood disease affecting honey bees. It may lead to lethal infections of larvae and, in severe cases, even to colony...
European foulbrood is a globally distributed brood disease affecting honey bees. It may lead to lethal infections of larvae and, in severe cases, even to colony collapse. Lately, a profound genetic and phenotypic diversity was documented for the causative agent Melissococcus plutonius. However, experimental work on the impact of diverse M. plutonius strains on hosts with different genetic background is completely lacking and the role of secondary invaders is poorly understood. Here, we address these issues and elucidate the impact and interaction of both host and pathogen on one another. Moreover, we try to unravel the role of secondary bacterial invasions in foulbrood-diseased larvae. We employed in vitro infections with honey bee larvae from queens with different genetic background and three different M. plutonius strains. Larvae infection experiments showed host-dependent survival dynamics although M. plutonius strain 49.3 consistently had the highest virulence. This pattern was also reflected in significantly reduced weights of 49.3 strain-infected larvae compared to the other treatments. No difference was found in groups additionally inoculated with a secondary invader (Enterococcus faecalis or Paenibacillus alvei) neither in terms of larval survival nor weight. These results suggest that host background contributes markedly to the course of the disease but virulence is mainly dependent on pathogen genotype. Secondary invaders following a M. plutonius infection do not increase disease lethality and therefore may just be a colonization of weakened and immunodeficient, or dead larvae.
Topics: Animals; Bees; Enterococcaceae; Gram-Positive Bacterial Infections; Host-Pathogen Interactions; Larva; Paenibacillus; Survival Analysis
PubMed: 29799173
DOI: 10.1002/mbo3.649 -
The Science of the Total Environment Dec 2020The pesticides belonging the strobilurin group are among the most common contaminants in the environment. In this work, biodegradation studies of the strobilurin...
The pesticides belonging the strobilurin group are among the most common contaminants in the environment. In this work, biodegradation studies of the strobilurin fungicide Pyraclostrobin by bacteria from orange cultivation plots were performed aiming to contribute with the development of a bioremediation method. Experiments were performed in triplicate with validated methods, and optimization was performed by Central Composite Design and Response Surface Methodology. The strains were evaluated in liquid nutrient medium containing 100 mg L of Pyraclostrobin, and decreased concentrations of 61.5 to 100.5 mg L were determined after 5 days at 37 °C and 130 rpm, showing the importance of strain selection. When the five most efficient strains (Bacillus sp. CSA-13, Paenibacillus alvei CBMAI2221, Bacillus sp. CBMAI2222, Bacillus safensis CBMAI2220 and Bacillus aryabhattai CBMAI2223) were used in consortia, synergistic and antagonistic effects were observed accordingly to the employed combination of bacteria, resulting in 64.2 ± 3.9 to 95.4 ± 4.9 mg L residual Pyraclostrobin. In addition, the formation of 1-(4-chlorophenyl)-1H-pyrazol-3-ol was quantified (0.59-0.01 mg L), and a new biodegradation pathway was proposed with 15 identified metabolites. Experiments were also performed in soil under controlled conditions (30 °C, 0-28 days, 100 mg kg pesticide), and the native microbiome reduced the pesticide concentration to 70.4 ± 2.3 mg L, whereas the inoculation of an efficient bacterial consortium promoted clearly better results, 57.2 ± 3.9 mg L residual Pyraclostrobin. This suggests that the introduction of these strains in soil in a bioaugmentation process increases decontamination. However, the native microbiome is important for a more efficient bioremediation.
Topics: Bacillus; Bacteria; Biodegradation, Environmental; Citrus sinensis; Fungicides, Industrial; Paenibacillus; Soil Microbiology; Soil Pollutants; Strobilurins
PubMed: 32763599
DOI: 10.1016/j.scitotenv.2020.140968 -
ACS Chemical Biology Apr 2024Glycosyltransferases play a fundamental role in the biosynthesis of glycoproteins and glycotherapeutics. In this study, we investigated protein glycosyltransferase...
Glycosyltransferases play a fundamental role in the biosynthesis of glycoproteins and glycotherapeutics. In this study, we investigated protein glycosyltransferase FlgGT1, belonging to the GT2 family. The GT2 family includes cysteine S-glycosyltransferases involved in antimicrobial peptide biosyntheses, sharing conserved catalytic domains while exhibiting diverse C-terminal domains. Our studies revealed that FlgGT1 recognizes structural motifs rather than specific amino acid sequences when glycosylating the flagellin protein Hag. Notably, FlgGT1 is selective for serine or threonine -glycosylation over cysteine -glycosylation. Molecular dynamics simulations provided insights into the structural basis of FlgGT1's ability to accommodate various sugar nucleotides as donor substrates. Mutagenesis experiments on FlgGT1 demonstrated that truncating the relatively large C-terminal domain resulted in a loss of flagellin glycosylation activity. Our classification based on sequence similarity network analysis and AlphaFold2 structural predictions suggests that the acquisition of the C-terminal domain is a key evolutionary adaptation conferring distinct substrate specificities on glycosyltransferases within the GT2 family.
Topics: Amino Acid Sequence; Cysteine; Flagellin; Glycosylation; Glycosyltransferases; Paenibacillus
PubMed: 38562012
DOI: 10.1021/acschembio.4c00045