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Applied and Environmental Microbiology Sep 2023WLY78, a N-fixing bacterium, has great potential use as a biofertilizer in agriculture. Recently, we have revealed that GlnR positively and negatively regulates the...
WLY78, a N-fixing bacterium, has great potential use as a biofertilizer in agriculture. Recently, we have revealed that GlnR positively and negatively regulates the transcription of the (trogen ixation) operon () in WLY78 by binding to two loci of the promoter according to nitrogen availability. However, the regulatory mechanisms of nitrogen metabolism mediated by GlnR in the genus remain unclear. In this study, we have revealed that glutamine synthetase (GS) and GlnR in WLY78 play a key role in the regulation of nitrogen metabolism. GS (encoded by within ) and GS1 (encoded by ) belong to distinct groups: GSI-α and GSI-β. Both GS and GS1 have the enzyme activity to convert NH and glutamate into glutamine, but only GS is involved in the repression by GlnR. GlnR represses transcription of under excess nitrogen, while it activates the expression of under nitrogen limitation. GlnR simultaneously activates and represses the expression of and in response to nitrogen availability. Also, GlnR regulates the expression of and . IMPORTANCE In this study, we have revealed that GlnR uses multiple mechanisms to regulate nitrogen metabolism. GlnR activates or represses or simultaneously activates and inhibits the transcription of nitrogen metabolism genes in response to nitrogen availability. The multiple regulation mechanisms employed by GlnR are very different from GlnR which represses nitrogen metabolism under excess nitrogen. Both GS encoded by within the operon and GS1 encoded by in WLY78 are involved in ammonium assimilation, but only GS is required for regulating GlnR activity. The work not only provides significant insight into understanding the interplay of GlnR and GS in nitrogen metabolism but also provides guidance for improving nitrogen fixation efficiency by modulating nitrogen metabolism.
PubMed: 37668407
DOI: 10.1128/aem.00139-23 -
PloS One 2021Paenibacillus spp. exopolysaccharides (EPSs) have become a growing interest recently as a source of biomaterials. In this study, we characterized Paenibacillus polymyxa...
Paenibacillus spp. exopolysaccharides (EPSs) have become a growing interest recently as a source of biomaterials. In this study, we characterized Paenibacillus polymyxa 2020 strain, which produces a large quantity of EPS (up to 68 g/L),and was isolated from wasp honeycombs. Here we report its complete genome sequence and full methylome analysis detected by Pacific Biosciences SMRT sequencing. Moreover, bioinformatic analysis identified a putative levan synthetic operon. SacC and sacB genes have been cloned and their products identified as glycoside hydrolase and levansucrase respectively. The Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectra demonstrated that the EPS is a linear β-(2→6)-linked fructan (levan). The structure and properties of levan polymer produced from sucrose and molasses were analyzed by FT-IR, NMR, scanning electron microscopy (SEM), high performance size exclusion chromatography (HPSEC), thermogravimetric analysis (TGA), cytotoxicity tests and showed low toxicity and high biocompatibility. Thus, P. polymyxa 2020 could be an exceptional cost-effective source for the industrial production of levan-type EPSs and to obtain functional biomaterials based on it for a broad range of applications, including bioengineering.
Topics: Cloning, Molecular; Epigenome; Magnetic Resonance Spectroscopy; Microscopy, Electron, Scanning; Paenibacillus polymyxa; Polysaccharides, Bacterial; Sequence Analysis, DNA; Spectrometry, X-Ray Emission; Spectroscopy, Fourier Transform Infrared
PubMed: 34228741
DOI: 10.1371/journal.pone.0253482 -
BMC Microbiology Mar 2021Paenibacillus polymyxa SC2, a bacterium isolated from the rhizosphere soil of pepper (Capsicum annuum L.), promotes growth and biocontrol of pepper. However, the...
BACKGROUND
Paenibacillus polymyxa SC2, a bacterium isolated from the rhizosphere soil of pepper (Capsicum annuum L.), promotes growth and biocontrol of pepper. However, the mechanisms of interaction between P. polymyxa SC2 and pepper have not yet been elucidated. This study aimed to investigate the interactional relationship of P. polymyxa SC2 and pepper using transcriptomics.
RESULTS
P. polymyxa SC2 promotes growth of pepper stems and leaves in pot experiments in the greenhouse. Under interaction conditions, peppers stimulate the expression of genes related to quorum sensing, chemotaxis, and biofilm formation in P. polymyxa SC2. Peppers induced the expression of polymyxin and fusaricidin biosynthesis genes in P. polymyxa SC2, and these genes were up-regulated 2.93- to 6.13-fold and 2.77- to 7.88-fold, respectively. Under the stimulation of medium which has been used to culture pepper, the bacteriostatic diameter of P. polymyxa SC2 against Xanthomonas citri increased significantly. Concurrently, under the stimulation of P. polymyxa SC2, expression of transcription factor genes WRKY2 and WRKY40 in pepper was up-regulated 1.17-fold and 3.5-fold, respectively.
CONCLUSIONS
Through the interaction with pepper, the ability of P. polymyxa SC2 to inhibit pathogens was enhanced. P. polymyxa SC2 also induces systemic resistance in pepper by stimulating expression of corresponding transcription regulators. Furthermore, pepper has effects on chemotaxis and biofilm formation of P. polymyxa SC2. This study provides a basis for studying interactional mechanisms of P. polymyxa SC2 and pepper.
Topics: Capsicum; Gene Expression Regulation, Plant; Genes, Plant; Host Microbial Interactions; Paenibacillus polymyxa; Rhizosphere; Transcriptome
PubMed: 33663386
DOI: 10.1186/s12866-021-02132-2 -
Frontiers in Cellular and Infection... 2022To discover novel microbial pesticide for controlling rice bacterial disease, polymyxin B and E were firstly isolated from the supernatant of fermentation broth of by...
To discover novel microbial pesticide for controlling rice bacterial disease, polymyxin B and E were firstly isolated from the supernatant of fermentation broth of by bioactivity tracking separation. It is shown that polymyxin B and E had remarkable inhibitory activities to pv. () and pv. () with the EC values of 0.19 μg/ml and 0.21 μg/ml against , and 0.32 μg/ml and 0.41 μg/ml against , respectively, which were better than those of Zhongshengmycin (0.31 μg/ml and 0.73 μg/ml) and Bismerthiazol (77.48 μg/ml and 85.30 μg/ml). Polymyxins B and E had good protection and curative activities against rice bacterial leaf blight (BLB) and rice bacterial leaf streak (BLS) . The protection and curative activities of polymyxins B (45.8 and 35.8%, respectively) and E (41.2 and 37.0%, respectively) to BLB were superior to those of Zhongshengmycin (34.8 and 29.8%, respectively) and Bismerthiazol (38.0 and 33.5%, respectively). Meanwhile, the protection and curative activities of polymyxins B (44.8 and 39.8%, respectively) and E (42.9 and 39.9%, respectively) to BLS were also superior to those of Zhongshengmycin (39.7 and 32.0%, respectively) and Bismerthiazol (41.5 and 34.3%, respectively). Polymyxin B exerted the anti-pesticide properties destroying the cell integrity of , reducing its infectivity and enhancing rice resistance against pathogens through activating the phenylpropanoid biosynthesis pathway of rice. It is indicated that polymyxin B and E were potential microbial pesticides for controlling rice bacterial disease.
Topics: Anti-Bacterial Agents; Bacterial Infections; Oryza; Paenibacillus polymyxa; Plant Diseases; Polymyxins; Xanthomonas
PubMed: 35419296
DOI: 10.3389/fcimb.2022.866357 -
Microbial Cell Factories Dec 2016Isolated from a wide range of sources, the genus Paenibacillus comprises bacterial species relevant to humans, animals, plants, and the environment. Many Paenibacillus... (Review)
Review
Isolated from a wide range of sources, the genus Paenibacillus comprises bacterial species relevant to humans, animals, plants, and the environment. Many Paenibacillus species can promote crop growth directly via biological nitrogen fixation, phosphate solubilization, production of the phytohormone indole-3-acetic acid (IAA), and release of siderophores that enable iron acquisition. They can also offer protection against insect herbivores and phytopathogens, including bacteria, fungi, nematodes, and viruses. This is accomplished by the production of a variety of antimicrobials and insecticides, and by triggering a hypersensitive defensive response of the plant, known as induced systemic resistance (ISR). Paenibacillus-derived antimicrobials also have applications in medicine, including polymyxins and fusaricidins, which are nonribosomal lipopeptides first isolated from strains of Paenibacillus polymyxa. Other useful molecules include exo-polysaccharides (EPS) and enzymes such as amylases, cellulases, hemicellulases, lipases, pectinases, oxygenases, dehydrogenases, lignin-modifying enzymes, and mutanases, which may have applications for detergents, food and feed, textiles, paper, biofuel, and healthcare. On the negative side, Paenibacillus larvae is the causative agent of American Foulbrood, a lethal disease of honeybees, while a variety of species are opportunistic infectors of humans, and others cause spoilage of pasteurized dairy products. This broad review summarizes the major positive and negative impacts of Paenibacillus: its realised and prospective contributions to agriculture, medicine, process manufacturing, and bioremediation, as well as its impacts due to pathogenicity and food spoilage. This review also includes detailed information in Additional files 1, 2, 3 for major known Paenibacillus species with their locations of isolation, genome sequencing projects, patents, and industrially significant compounds and enzymes. Paenibacillus will, over time, play increasingly important roles in sustainable agriculture and industrial biotechnology.
Topics: Animals; Gram-Positive Bacterial Infections; Humans; Paenibacillus
PubMed: 27905924
DOI: 10.1186/s12934-016-0603-7 -
Insects Jul 2022Arthropods are reported to serve as vectors of transmission of pathogenic microorganisms to humans, animals, and the environment. The aims of our study were (i) to...
Arthropods are reported to serve as vectors of transmission of pathogenic microorganisms to humans, animals, and the environment. The aims of our study were (i) to identify the external bacteriota of spiders inhabiting a chicken farm and slaughterhouse and (ii) to detect antimicrobial resistance of the isolates. In total, 102 spiders of 14 species were collected from a chicken farm, slaughterhouse, and buildings located in west Slovakia in 2017. Samples were diluted in peptone buffered water, and Tryptone Soya Agar (TSA), Triple Sugar Agar (TSI), Blood Agar (BA), and Anaerobic Agar (AA) were used for inoculation. A total of 28 genera and 56 microbial species were isolated from the samples. The most abundant species were (28 isolates) and (28 isolates). The least isolated species were (one isolate), (two isolates), (two isolates), and (two isolates). There were differences in microbial composition between the samples originating from the slaughterhouse, chicken farm, and buildings. The majority of the bacterial isolates resistant to antibiotics were isolated from the chicken farm. The isolation of potentially pathogenic bacteria such as , , and spp., which possess multiple drug resistance, is of public health concern.
PubMed: 36005303
DOI: 10.3390/insects13080680 -
Nature Communications Sep 2023The rhizosheath, or the layer of soil closely adhering to roots, can help plants to tolerate drought under moderate soil drying conditions. Rhizosheath formation is the...
The rhizosheath, or the layer of soil closely adhering to roots, can help plants to tolerate drought under moderate soil drying conditions. Rhizosheath formation is the result of poorly understood interactions between root exudates, microbes, and soil conditions. Here, we study the roles played by the soil microbiota in rhizosheath formation in barley (a dry crop). We show that barley rhizosheath formation is greater in acid soil than in alkaline soil, and inoculation with microbiota from acid soil enhances rhizosheath formation in alkaline soil. The rhizosheath-promoting activity is associated with the presence of Flavobacteriaceae and Paenibacillaceae bacteria that express genes for biosynthesis of indole-3-acetic acid (IAA, a common auxin), as determined by metagenomics and metatranscriptomics. Two bacterial strains isolated from rhizosheath (Chryseobacterium culicis and Paenibacillus polymyxa) produce IAA and enhance barley rhizosheath formation, while their IAA-defective mutants are unable to promote rhizosheath formation. Co-inoculation with the IAA-producing strains enhances barley grain yield in field experiments through an increase in spike number. Our findings contribute to our understanding of barley rhizosheath formation, and suggest potential strategies for crop improvement.
Topics: Hordeum; Bacteria; Desiccation; Indoleacetic Acids; Soil
PubMed: 37726263
DOI: 10.1038/s41467-023-40916-4 -
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 -
Methods in Molecular Biology (Clifton,... 2024In recent years, the clustered regularly interspaced palindromic repeats-Cas (CRISPR-Cas) technology has become the method of choice for precision genome editing in many...
In recent years, the clustered regularly interspaced palindromic repeats-Cas (CRISPR-Cas) technology has become the method of choice for precision genome editing in many organisms due to its simplicity and efficacy. Multiplex genome editing, point mutations, and large genomic modifications are attractive features of the CRISPR-Cas9 system. These applications facilitate both the ease and velocity of genetic manipulations and the discovery of novel functions. In this protocol chapter, we describe the use of a CRISPR-Cas9 system for multiplex integration and deletion modifications, and deletions of large genomic regions by the use of a single guide RNA (sgRNA), and, finally, targeted point mutation modifications in Paenibacillus polymyxa.
Topics: Gene Editing; CRISPR-Cas Systems; RNA, Guide, CRISPR-Cas Systems; Paenibacillus polymyxa; Genome
PubMed: 38468094
DOI: 10.1007/978-1-0716-3658-9_16 -
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