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Biotechnology For Biofuels and... Aug 2022Paenibacillus polymyxa is a typical plant growth-promoting rhizobacterium (PGPR), and synthesis of indole-3-acetic acid (IAA) is one of the reasons for its...
BACKGROUND
Paenibacillus polymyxa is a typical plant growth-promoting rhizobacterium (PGPR), and synthesis of indole-3-acetic acid (IAA) is one of the reasons for its growth-promoting capacity. The synthetic pathways of IAA in P. polymyxa must be identified and modified.
RESULTS
P. polymyxa SC2 and its spontaneous mutant SC2-M1 could promote plant growth by directly secreting IAA. Through metabonomic and genomic analysis, the genes patA, ilvB3, and fusE in the native IPyA pathway of IAA synthesis in strain SC2-M1 were predicted. A novel strong promoter P was rationally selected, synthetically analyzed, and then evaluated on its ability to express IAA synthetic genes. Co-expression of three genes, patA, ilvB3, and fusE, increased IAA yield by 60% in strain SC2-M1. Furthermore, the heterogeneous gene iaam of the IAM pathway and two heterogeneous IPyA pathways of IAA synthesis were selected to improve the IAA yield of strain SC2-M1. The genes ELJP6_14505, ipdC, and ELJP6_00725 of the entire IPyA pathway from Enterobacter ludwigii JP6 were expressed well by promoter P in strain SC2-M1 and increased IAA yield in the engineered strain SC2-M1 from 13 to 31 μg/mL, which was an increase of 138%.
CONCLUSIONS
The results of our study help reveal and enhance the IAA synthesis pathways of P. polymyxa and its future application.
PubMed: 35953838
DOI: 10.1186/s13068-022-02181-3 -
Journal of Microbiology (Seoul, Korea) Aug 2021Paenibacillus polymyxa is a promising plant-growth-promoting rhizobacterium that associates with a wide range of host plants, including agronomically important ones....
Paenibacillus polymyxa is a promising plant-growth-promoting rhizobacterium that associates with a wide range of host plants, including agronomically important ones. Inoculation of wheat seedlings with P. polymyxa strains CCM 1465 and 92 was found to increase the mitotic index of the root cells 1.2- and 1.6-fold, respectively. Treatment of seedlings with the exopolysaccharides (EPSs) of these strains increased the mitotic index 1.9-fold (P. polymyxa CCM 1465) and 2.8-fold (P. polymyxa 92). These increases indicate activation of cell division in the root meristems. Analysis of the morphometric variables of the seedlings showed that P. polymyxa CCM 1465, P. polymyxa 92, and their EPSs promoted wheat growth, increasing root and shoot length up to 22% and root and shoot dry weight up to 28%, as compared with the control. In addition, both strains were found to intensely colonize the seedling root surface. Thus, P. polymyxa EPSs are active metabolites that, along with whole cells, are responsible for the contact interactions of the bacteria with wheat roots and are implicated in the induction of plant responses to these interactions. The strains used in this work are of interest for further study to broaden the existing understanding of the mechanisms of plant-bacterial interactions and to develop effective biofertilizers for agricultural purposes.
Topics: Agricultural Inoculants; Paenibacillus polymyxa; Plant Roots; Polysaccharides, Bacterial; Seedlings; Soil Microbiology; Triticum
PubMed: 34302621
DOI: 10.1007/s12275-021-0623-9 -
Frontiers in Chemistry 2022Microbial bactericides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, Y-1...
Microbial bactericides have been a research hotspot in recent years. In order to find new microbial fungicides for preventing and treating rice bacterial diseases, Y-1 ( Y-1) was isolated from in this study, and the optimal medium was selected by a single-factor experiment, and then eight metabolites were isolated from Y-1 fermentation broth by bioactivity tracking separation. The bioassay results showed that 2,4-di-tert-butylphenol, N-acetyl-5-methoxytryptamine, and P-hydroxybenzoic acid have good antibacterial activity against pv. () and pv. (), with 50% effective concentration values of 49.45 μg/ml, 64.22 μg/ml, and 16.32 μg/ml to , and 34.33 μg/ml, 71.17 μg/ml, and 15.58 μg/ml to , respectively, compared with zhongshengmycin (0.42 and 0.82 μg/ml, respectively) and bismerthiazol (85.64 and 92.49 μg/ml, respectively). experiments found that 2,4-di-tert-butylphenol (35.9 and 35.4%, respectively), N-acetyl-5-methoxytryptamine (42.9 and 36.7%, respectively), and P-hydroxybenzoic acid (40.6 and 36.8%, respectively) demonstrated excellent protective and curative activity against rice bacterial leaf blight, which were better than that of zhongshengmycin (38.4 and 34.4%, respectively). In addition, after 2,4-di-tert-butylphenol, N-acetyl-5-methoxytryptamine, and P-hydroxybenzoic acid acted on rice, SOD, POD, and CAD defense enzymes increased under the same condition. In conclusion, these results indicated that the activity and mechanism research of new microbial pesticides were helpful for the prevention and control of rice bacterial diseases.
PubMed: 35425761
DOI: 10.3389/fchem.2022.879724 -
Metabolic Engineering Sep 2020Paenibacillus polymyxa is a Gram-positive, non-pathogenic soil bacterium that has been extensively investigated for the production of R-,R-2,3-butanediol in...
Paenibacillus polymyxa is a Gram-positive, non-pathogenic soil bacterium that has been extensively investigated for the production of R-,R-2,3-butanediol in exceptionally high enantiomeric purity. Rational metabolic engineering efforts to increase productivity and product titers were restricted due to limited genetic accessibility of the organism up to now. By use of CRISPR-Cas9 mediated genome editing, six metabolic mutant variants were generated and compared in batch fermentations for the first time. Downstream processing was facilitated by completely eliminating exopolysaccharide formation through the combined knockout of the sacB gene and the clu1 region, encoding for the underlying enzymatic machinery of levan and paenan synthesis. Spore formation was inhibited by deletion of spoIIE, thereby disrupting the sporulation cascade of P. polymyxa. Optimization of the carbon flux towards 2,3-butanediol was achieved by deletion of the lactate dehydrogenase ldh1 and decoupling of the butanediol dehydrogenase from its natural regulation via constitutive episomal expression. The improved strain showed 45 % increased productivity, reaching a final concentration of 43.8 g L butanediol. A yield of 0.43 g g glucose was achieved, accounting for 86 % of the theoretical maximum.
Topics: Butylene Glycols; CRISPR-Cas Systems; Gene Editing; Metabolic Engineering; Paenibacillus polymyxa
PubMed: 32771627
DOI: 10.1016/j.ymben.2020.07.009 -
Journal of Applied Microbiology Nov 2022We aimed to enhance the antibacterial and growth-promoting effects of Paenibacillus polymyxa by improving the yield of spores, lipopeptides and indole-3-acetic acid...
AIMS
We aimed to enhance the antibacterial and growth-promoting effects of Paenibacillus polymyxa by improving the yield of spores, lipopeptides and indole-3-acetic acid (IAA) in the fermentation process.
METHODS AND RESULTS
Through medium optimization by the response surface method and feeding fermentation, the number of spores reached 2.37 × 10 cfu ml with an increase of 38%, the content of lipopeptides reached 60.8 mg L with an increase of 89%, and the content of IAA reached 24.3 mg L with an increase of 176%, respectively, comparing with the original (un-optimized) culture conditions. The fermentation culture of P. polymyxa from the optimized medium and feeding fermentation resulted in higher colonization of P. polymyxa in soils than that from the original culture during the 49 days for testing. Comparing with the supernatant of the original culture, the supernatant of the P. polymyxa culture from the optimized medium and feeding fermentation showed enhanced antibacterial effects and plant growth-promoting effects. The enhanced antibacterial effect was shown as the increase of the inhibition zone by 59%, 45% and 26% against Ralstonia solanacearum, Erwinia carotovora and Xanthomonas campestris. The enhanced growth-promoting effects on tomato and strawberry plants were the increase of plant height by 47% and 5%, root length by 23% and 15% and root weight by 65% and 110%.
CONCLUSIONS
The combination of medium optimization and feeding fermentation effectively improved the yield of spores, lipopeptides and IAA. Lipopeptides and IAA lead to enhanced antibacterial and plant growth-promoting effects of the P. polymyxa product.
SIGNIFICANCE AND IMPACT OF THIS STUDY
The optimized fermentation method significantly improved the yield of spores, lipopeptides and IAA, thus providing theoretical and technical support for enhancing the antibacterial and growth-promoting effects of P. polymyxa products in agriculture.
Topics: Paenibacillus polymyxa; Fermentation; Anti-Bacterial Agents; Lipopeptides; Soil; Paenibacillus
PubMed: 35938320
DOI: 10.1111/jam.15750 -
Frontiers in Microbiology 2023Pitaya canker, caused by , is one of the most important fungal diseases that cause significant losses in production. To replace chemical pesticides, the use of...
Pitaya canker, caused by , is one of the most important fungal diseases that cause significant losses in production. To replace chemical pesticides, the use of biocontrol strains to manage plant diseases has been the focus of research. In this study, the bacterial strain AF01, identified as , exhibited significant antifungal effects against and four other pitaya fungal pathogens. The strain AF01 produces 13 fusaricidins, which directly inhibit mycelial growth, spore germination and germ tube elongation by causing the membrane integrity and cell ultrastructure to incur irreversible damage. Pot experiment and yield test confirmed that AF01 provided preservative effects by reducing the disease index. In comparison to the untreated control groups, RNA-seq data showed that AF01 selectively blocked some transcription and translation processes and inhibited RNA and DNA structural dynamics, energy production and conversion, and signal transduction, particularly cell wall biosynthesis, changes in membrane permeability, and impairment of protein biosynthesis. Thus, AF01 could be potentially useful as a suitable biocontrol agent for pitaya canker.
PubMed: 37266020
DOI: 10.3389/fmicb.2023.1188722 -
Poultry Science Feb 2024The search for a natural antimicrobial agent is ongoing and critical because of the rise and rapid proliferation of antibiotic-resistant pathogenic bacteria. The current...
Dietary Paenibacillus polymyxa AM20 as a new probiotic: Improving effects on IR broiler growth performance, hepatosomatic index, thyroid hormones, lipid profile, immune response, antioxidant parameters, and caecal microorganisms.
The search for a natural antimicrobial agent is ongoing and critical because of the rise and rapid proliferation of antibiotic-resistant pathogenic bacteria. The current study aims to examine the effect of Paenibacillus polymyxa AM20 as an alternative antibiotic and feed additive on Indian river broiler performance, digestive enzymes, thyroid hormones, lipid profile, hepatosomatic index, immunological response, gut bacteria, and antioxidant parameters. The bacterial isolate AM20 was identified at the gene level by isolating DNA and using PCR to detect genes. Based on 16S rRNA gene sequence analysis, the bacterial isolate was identified as Paenibacillus polymyxa. One hundred twenty Indian river broilers (1-day old) were randomly divided into 4 groups of 10 chicks each, with 3 replicates. The control group was fed a basal diet only, while the other 3 were administered control diets supplemented with P. polymyxa at 3 concentrations: 0.5, 1, and 1.5 mg/kg. The findings revealed that all groups that received graded amounts of P. polymyxa increased all growth parameters throughout the study. P. polymyxa treatment at 1.5 mg/kg increased body gain by 9% compared to the control due to increased feed intake (P = 0.0001), growth rate (P = 0.0001), and decreased feed conversion ratio. Compared to the control group, P. polymyxa (1.5 mg/kg) enhanced kidney functions in chickens by reducing uric acid and creatinine levels (P = 0.0451). Compared to the control group, alanine aminotransferase and aspartate transaminase levels in the liver were significantly reduced at all P. polymyxa doses. Liver function values were highest for P. polymyxa at 1.5 mg/kg. Compared to the control group, those whose diets included P. polymyxa had significantly better blood cholesterol levels, high-density lipoprotein, low-density lipoprotein, immunological response, thyroid function, and gut microbiota. In general, broiler chickens' economic efficiency was improved by including P. polymyxa in their diet, which also improved their growth performance, carcass dressing, specific blood biochemical levels and enzymes, and the composition of the gut microbiota.
Topics: Animals; Antioxidants; Chickens; Paenibacillus polymyxa; RNA, Ribosomal, 16S; Diet; Dietary Supplements; Probiotics; Anti-Bacterial Agents; Immunity; Thyroid Hormones; Lipids; Animal Feed
PubMed: 38035472
DOI: 10.1016/j.psj.2023.103239 -
Dissection of NSY50-Induced Defense in Cucumber Roots against f. sp. by Target Metabolite Profiling.Biology Jul 2022To gain insights into the roles of beneficial PGPR in controlling soil-borne disease, we adopted a metabolomics approach to investigate the beneficial impacts of NSY50...
To gain insights into the roles of beneficial PGPR in controlling soil-borne disease, we adopted a metabolomics approach to investigate the beneficial impacts of NSY50 on cucumber seedling roots under the pathogen of f. sp. (FOC). We found that NSY50 pretreatment (NSY50 + FOC) obviously reduced the production of reactive oxygen species (ROS). Untargeted metabolomic analysis revealed that 106 metabolites responded to NSY50 and/or FOC inoculation. Under FOC stress, the contents of root osmotic adjustment substances, such as proline and betaine were significantly increased, and dehydroascorbic acid and oxidized glutathione (GSH) considerably accumulated. Furthermore, the contents of free amino acids such as tryptophan, phenylalanine, and glutamic acid were also significantly accumulated under FOC stress. Similarly, FOC stress adversely affected glycolysis and the tricarboxylic acid cycles and transferred to the pentose phosphate pathway. Conversely, NSY50 + FOC better promoted the accumulation of α-ketoglutaric acid, ribulose-5-phosphate, and 7-phosphosodiheptanone compared to FOC alone. Furthermore, NSY50 + FOC activated GSH metabolism and increased GSH synthesis and metabolism-related enzyme activity and their encoding gene expressions, which may have improved redox homoeostasis, energy flow, and defense ability. Our results provide a novel perspective to understanding the function of NSY50, accelerating the application of this beneficial PGPR in sustainable agricultural practices.
PubMed: 36101409
DOI: 10.3390/biology11071028 -
Chemistry & Biology Dec 2011Polymyxins are cationic lipopeptide antibiotics active against many species of Gram-negative bacteria. We sequenced the gene cluster for polymyxin biosynthesis from...
Polymyxins are cationic lipopeptide antibiotics active against many species of Gram-negative bacteria. We sequenced the gene cluster for polymyxin biosynthesis from Paenibacillus polymyxa PKB1. The 40.8 kb gene cluster comprises three nonribosomal peptide synthetase-encoding genes and two ABC transporter-like genes. Disruption of a peptide synthetase gene abolished all antibiotic production, whereas deletion of one or both transporter genes only reduced antibiotic production. Computational analysis of the peptide synthetase modules suggested that the enzyme system produces variant forms of polymyxin B (1 and 2), with D-2,4-diaminobutyrate instead of L-2,4-diaminobutyrate in amino acid position 3. Two antibacterial metabolites were resolved by HPLC and identified by high-resolution mass spectrometry and MS/MS sequencing as the expected variants 3 and 4 of polymyxin B(1) (1) and B(2) (2). Stereochemical analysis confirmed the presence of both D-2,4-diaminobutyrate and L-2,4-diaminobutyrate residues.
Topics: Anti-Bacterial Agents; Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Molecular Sequence Data; Multigene Family; Paenibacillus; Peptide Synthases; Polymyxins; Stereoisomerism; Tandem Mass Spectrometry
PubMed: 22195566
DOI: 10.1016/j.chembiol.2011.09.017 -
Carbohydrate Polymers Jul 2023Paenibacillus polymyxa is a Gram-positive soil bacterium known for producing a wide range of exopolysaccharides. However, due to the biopolymer's complexity, structural...
Paenibacillus polymyxa is a Gram-positive soil bacterium known for producing a wide range of exopolysaccharides. However, due to the biopolymer's complexity, structural elucidation has so far been inconclusive. Combinatorial knock-outs of glycosyltransferases were generated in order to separate distinct polysaccharides produced by P. polymyxa. Using a complementary analytical approach consisting of carbohydrate fingerprints, sequence analysis, methylation analysis as well as NMR spectroscopy, the structure of the repeating units of two additional heteroexopolysaccharides termed paenan I and paenan III were elucidated. Results for paenan I identified a trisaccharide backbone consisting of 1➔4-β-d-Glc, 1➔4-β-d-Man and a 1,3,4-branching β-d-Gal residue with a sidechain comprising of a terminal β-d-Gal and 1➔3-β-d-Glc. For paenan III, results indicated a backbone consisting of 1➔3-β-d-Glc, 1,3,4-linked α-d-Man and 1,3,4-linked α-d-GlcA. NMR analysis indicated monomeric β-d-Glc and α-d-Man sidechains for the branching Man and GlcA residues respectively.
Topics: Humans; Carbohydrate Sequence; Paenibacillus polymyxa; CRISPR-Cas Systems; Polysaccharides; Magnetic Resonance Spectroscopy
PubMed: 37059525
DOI: 10.1016/j.carbpol.2023.120763