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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 -
Genes & Genetic Systems Aug 2020Paenibacillus polymyxa is a well-known Gram-positive biocontrol bacterium. It has been reported that many P. polymyxa strains can inhibit bacteria, fungi and other plant...
Paenibacillus polymyxa is a well-known Gram-positive biocontrol bacterium. It has been reported that many P. polymyxa strains can inhibit bacteria, fungi and other plant pathogens. Paenibacillus polymyxa employs a variety of mechanisms to promote plant growth, so it is necessary to understand the biocontrol ability of bacteria at the genome level. In the present study, thanks to the widespread availability of Paenibacillus genome data and the development of bioinformatics tools, we were able to analyze and mine the genomes of 43 P. polymyxa strains. The strain NCTC4744 was determined not to be P. polymyxa according to digital DNA-DNA hybridization and average nucleotide identity. By analysis of the pan-genome and the core genome, we found that the pan-genome of P. polymyxa was open and that there were 3,192 core genes. In a gene cluster analysis of secondary metabolites, 797 secondary metabolite gene clusters were found, of which 343 are not similar to known clusters and are expected to reveal a large number of new secondary metabolites. We also analyzed the plant growth-promoting genes that were mined and found, surpisingly, that these genes are highly conserved. The results of the present study not only reveal a large number of unknown potential secondary metabolite gene clusters in P. polymyxa, but also suggest that plant growth promotion characteristics are evolutionary adaptations of P. polymyxa to plant-related habitats.
Topics: Biological Control Agents; Data Mining; Genome, Bacterial; Genomics; Metabolome; Metabolomics; Paenibacillus polymyxa; Plants
PubMed: 32611933
DOI: 10.1266/ggs.19-00053 -
PloS One 2017Paenibacillus polymyxa WLY78 is a nitrogen fixer and it can be potentially applied to biofertilizer in agriculture. In this study, P. polymyxa WLY78 is labelled with gfp...
Paenibacillus polymyxa WLY78 is a nitrogen fixer and it can be potentially applied to biofertilizer in agriculture. In this study, P. polymyxa WLY78 is labelled with gfp gene. The GFP-labelled P. polymyxa WLY78 is used to inoculate wheat, maize and cucumber seedlings grown in the gnotobiotic system and in soil, respectively. Observation by confocal laser scanning microscope reveals that the GFP-labeled bacterial cells are mainly located on the root surface and epidermis of wheat, and only a few cells are present within cortical cells. In maize and cucumber seedlings, bacterial cells were colonized in epidermal and cortical cells, intercellular spaces and vascular system of root, stem and leaf tissue interiors besides on root surfaces. Higher densities of the bacterial cells in roots, stems and leaves indicated that P. polymyxa WLY78 cells could migrate from roots to stems and leaves of maize and cucumber. This study will provide insight into interaction between P. polymyxa WLY78 and host cells.
Topics: Cucumis sativus; Green Fluorescent Proteins; Organisms, Genetically Modified; Paenibacillus polymyxa; Plant Diseases; Plant Leaves; Plant Roots; Plant Stems; Seedlings; Soil Microbiology; Triticum; Zea mays
PubMed: 28076417
DOI: 10.1371/journal.pone.0169980 -
Animal Nutrition (Zhongguo Xu Mu Shou... Sep 2021With the ever-growing strict prohibitions on antibiotic growth promoters (AGP) in animal production, in-feed probiotics are becoming attractive alternatives to...
With the ever-growing strict prohibitions on antibiotic growth promoters (AGP) in animal production, in-feed probiotics are becoming attractive alternatives to antibiotics in the poultry industry. To investigate the effects of 10 and 16 on the growth performance and intestinal health of broilers, 540 male Cobb 500 broilers of 1 d old were randomly divided into 3 groups with 6 replicates per group and 30 chicks per replicate. Broilers were fed with either a basal diet or basal diets supplemented with 1 × 10 colony-forming units (CFU)/kg 10 (BSC10) or 16 (Lac16) for 42 d. Results showed that Lac16 treatment improved ( < 0.05) the growth performance (body weight and feed conversion) of broilers at the starter phase, while BSC10 treatment slightly improved ( > 0.05) the growth performance of the starter phase broilers. The increased villus height ( < 0.05) at d 14, 21 and 42 and villus height to crypt depth ratio ( < 0.05) at d 14 and 21 were observed in the ileum of the 2 probiotic groups. Besides, transmission electron microscopy results showed that the 2 probiotics enhanced the intestinal epithelial barrier. Both probiotic treatments up-regulated ( < 0.05) the mRNA expression of fatty acid binding protein 1 () and sodium-dependent glucose transporters-1 () in the ileal mucosa of broilers at d 21. In addition, BSC10 and Lac16 treatments significantly ( < 0.05) increased the relative abundance of short-chain fatty acids-producing bacteria, such as , , and , and significantly ( < 0.05) decreased the relative abundance of enteric pathogens (, and ). Furthermore, the 2 probiotic treatments also increased the positive connection among the intestinal microbes and the carbohydrate metabolism-related pathways of the intestinal bacteria ( < 0.05), with decreasing ( < 0.05) nucleotides biosynthesis-related pathways of the intestinal bacteria. Overall, these results suggest that the 2 probiotics, especially Lac16, have a potential beneficial effect on the growth performance and intestinal health of starter phase broilers.
PubMed: 34466687
DOI: 10.1016/j.aninu.2021.03.008 -
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 -
Biology Jul 2022The use of microbial products as natural biocontrol agents to increase a plant's systemic resistance to viral infections is a promising way to make agriculture more...
The use of microbial products as natural biocontrol agents to increase a plant's systemic resistance to viral infections is a promising way to make agriculture more sustainable and less harmful to the environment. The rhizobacterium has been shown to have strong biocontrol action against plant diseases, but its antiviral activity has been little investigated. Here, the efficiency of the culture filtrate of the strain SZYM (Acc# ON149452) to protect squash ( L.) plants against a (ZYMV, Acc# ON159933) infection was evaluated. Under greenhouse conditions, the foliar application of the culture filtrate of SZYM either in protective or curative treatment conditions enhanced squash growth, reduced disease severity, and decreased ZYMV accumulation levels in the treated plants when compared to the non-treated plants. The protective treatment group exhibited the highest inhibitory effect (80%), with significant increases in their total soluble carbohydrates, total soluble protein content, ascorbic acid content, and free radical scavenging activity. Furthermore, a considerable increase in the activities of reactive oxygen species scavenging enzymes (superoxide dismutase, polyphenol oxidase, and peroxidase) were also found. In addition, the induction of systemic resistance with a significant elevation in the transcriptional levels of polyphenolic pathway genes (, , and ) and pathogenesis-related genes ( and ) was observed. Out of the 14 detected compounds in the GC-MS analysis, propanoic acid, benzenedicarboxylic acid, tetradecanoic acid, and their derivatives, as well as pyrrolo [1,2-a] pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl) were the primary ingredient compounds in the ethyl acetate extract of the SZYM-culture filtrate. Such compounds may act as elicitor molecules that induce systemic resistance against viral infection. Consequently, can be considered a powerful plant growth-promoting bacterium (PGPB) in agricultural applications as well as a source of bioactive compounds for sustainable disease management. As far as we know, this is the first time that has been shown to fight viruses in plants.
PubMed: 36009777
DOI: 10.3390/biology11081150 -
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 -
BioMed Research International 2020is a plant growth-promoting rhizobacterium that has immense potential to be used as an environmentally friendly replacement of chemical fertilizers and pesticides. In...
is a plant growth-promoting rhizobacterium that has immense potential to be used as an environmentally friendly replacement of chemical fertilizers and pesticides. In the present study, SK1 was isolated from bulbs of . The isolated endophytic strain showed antifungal activities against important plant pathogens like , , , and . The highest percentage of growth inhibition, i.e., 66.67 ± 2.23%, was observed for SK1 against followed by 61.19 ± 3.12%, 60.71 ± 3.53%, and 55.54 ± 2.89% against , , and , respectively. The metabolite profiling of ethyl acetate fraction was assessed through the UHPLC-LTQ-IT-MS/MS analysis, and putative identification was done with the aid of the GNPS molecular networking workflow. A total of 29 compounds were putatively identified which included dipeptides, tripeptides, cyclopeptides (cyclo-(Leu-Leu), cyclo(Pro-Phe)), 2-heptyl-3-hydroxy 4-quinolone, 6-oxocativic acid, anhydrobrazilic acid, 1-(5-methoxy-1H-indol-3-yl)-2-piperidin-1-ylethane-1,2-dione, octadecenoic acid, pyochelin, 15-hydroxy-5Z,8Z,11Z, 13E-eicosatetraenoic acid, (Z)-7-[(2R,3S)-3-[(2Z,5E)-Undeca-2,5-dienyl]oxiran-2-yl]hept-5-enoic acid, arginylasparagine, cholic acid, sphinganine, elaidic acid, gossypin, L-carnosine, tetrodotoxin, and ursodiol. The high antifungal activity of SK1 might be attributed to the presence of these bioactive compounds. The isolated strain SK1 showed plant growth-promoting traits such as the production of organic acids, ACC deaminase, indole-3-acetic acid (IAA), siderophores, nitrogen fixation, and phosphate solubilization. IAA production was strongly correlated with the application of exogenous tryptophan concentrations in the medium. Furthermore, inoculation of SK1 enhanced plant growth of two varieties, Tresor and White Heaven, under greenhouse condition. In the light of these findings, the SK1 may be utilized as a source of plant growth promotion and disease control in sustainable agriculture.
Topics: Anti-Infective Agents; Ascomycota; Carbon-Carbon Lyases; Carboxylic Acids; Endophytes; Fusarium; Indoleacetic Acids; Lilium; Nitrogen Fixation; Paenibacillus polymyxa; Plant Diseases; Plant Growth Regulators; Plant Roots; Siderophores; Tandem Mass Spectrometry
PubMed: 32190683
DOI: 10.1155/2020/8650957 -
Frontiers in Immunology 2020This study aimed to investigate the protective effects of 16 (Lac16) and a 10 (BSC10) against (Cp) infection in broilers. A total of 720 one-day-old chicks were...
This study aimed to investigate the protective effects of 16 (Lac16) and a 10 (BSC10) against (Cp) infection in broilers. A total of 720 one-day-old chicks were randomly divided into four groups. The control and Cp group were only fed a basal diet, while the two treatment groups received basal diets supplemented with Lac16 (1 × 10 cfu·kg) and BSC10 (1 × 10 cfu·kg) for 21 days, respectively. On day 1 and days 14 to 20, birds except those in the control group were challenged with 1 × 10 cfu type A strain once a day. The results showed that both Lac16 and BSC10 could ameliorate intestinal structure damage caused by infection. infection induced apoptosis by increasing the expression of Bax and and decreasing Bcl-2 expression and inflammation evidence by higher levels of , , and in the ileum mucosa, and NO production in jejunal mucosa, which was reversed by Lac16 and BSC10 treatment except for ( 0.05). Besides, the two probiotics restored the intestinal microbiota imbalance induced by infection, characterized by the reduced and and the increased at the phyla level and decreased and at the genus level. The two probiotics also reversed metabolic pathways of the microbiota in -infected broilers, including B-vitamin biosynthesis, peptidoglycan biosynthesis, and pyruvate fermentation to acetate and lactate II pathway. In conclusion, Lac16 and BSC10 can effectively protect broilers against infection through improved composition and metabolic pathways of the intestinal microbiota, intestinal structure, inflammation, and anti-apoptosis.
Topics: Animals; Chickens; Clostridium Infections; Clostridium perfringens; Lactobacillus plantarum; Paenibacillus polymyxa; Poultry Diseases
PubMed: 33679724
DOI: 10.3389/fimmu.2020.628374 -
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