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3 Biotech Mar 2021Konjac glucomannan oligosaccharide has attracted much attention due to its broad biological activities. Specific glucomannan degrading enzymes are effective tools for...
Konjac glucomannan oligosaccharide has attracted much attention due to its broad biological activities. Specific glucomannan degrading enzymes are effective tools for the production of oligosaccharides from konjac glucomannan. However, there are still few reports of commercial enzymes that can specifically degrade konjac glucomannan. The gene encoding a glucomannanase consisting of 553 amino acids (61.5 kDa) from 3-3 was cloned and heterologous expressed in BL21 (DE3). The recombinant GluB showed high specificity for the degradation of konjac glucomannan. Moreover, the hydrolytic products of GluB degrade konjac glucomannan were a series of oligosaccharides with degrees of polymerisation of 2-12. Furthermore, the biochemical properties indicated that GluB is the optimal active at 45 to 55 °C and pH 5.0-6.0, and shows highly pH stability over a very broad pH range. The present characteristics indicated that GluB is a potential tool to be used to produce oligosaccharides from konjac glucomannan.
PubMed: 33680694
DOI: 10.1007/s13205-021-02676-0 -
The Journal of Antibiotics Nov 2022Polymyxins are a class of antibiotics that were discovered in 1947 from programs searching for compounds effective in the treatment of Gram-negative infections. Produced... (Review)
Review
Polymyxins are a class of antibiotics that were discovered in 1947 from programs searching for compounds effective in the treatment of Gram-negative infections. Produced by the Gram-positive bacterium Paenibacillus polymyxa and composed of a cyclic peptide chain with a peptide-fatty acyl tail, polymyxins exert bactericidal effects through membrane disruption. Currently, polymyxin B and colistin (polymyxin E) have been developed for clinical use, where they are reserved as "last-line" therapies for multidrug-resistant (MDR) infections. Unfortunately, the incidences of strains resistant to polymyxins have been increasing globally, and polymyxin heteroresistance has been gaining appreciation as an important clinical challenge. These phenomena, along with bacterial tolerance to this antibiotic class, constitute important contributors to polymyxin treatment failure. Here, we review polymyxins and their mechanism of action, summarize the current understanding of how polymyxin treatment fails, and discuss how the next generation of polymyxins holds promise to invigorate this antibiotic class.
Topics: Anti-Bacterial Agents; Colistin; Polymyxin B; Polymyxins; Treatment Failure
PubMed: 36123537
DOI: 10.1038/s41429-022-00561-3 -
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 -
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 -
Chembiochem : a European Journal of... Jun 2020Nitrogen is one of the most important nutrients for plant growth. To enhance crop productivity, chemical nitrogen fertilizer is commonly applied in agriculture.... (Review)
Review
Nitrogen is one of the most important nutrients for plant growth. To enhance crop productivity, chemical nitrogen fertilizer is commonly applied in agriculture. Biological nitrogen fixation, the conversion of atmospheric N to NH , is an important source of nitrogen input in agriculture and represents a promising substitute for chemical nitrogen fertilizers. However, nitrogen fixation is only sporadically distributed within bacteria and archaea (diazotrophs). Thus, many biologists hope to reconstitute a nitrogenase biosynthetic pathway in a eukaryotic host, with the final aim of developing N -fixing cereal crops. With the advent of synthetic biology and a deep understanding of the fundamental genetic determinants necessary to sustain nitrogen fixation in bacteria, much progress has been made toward this goal. Transfer of native and refactored nif (nitrogen fixation) genes to non-diazotrophs has been attempted in model bacteria, yeast, and plants. Specifically, nif genes from Klebsiella oxytoca, Azotobacter vinelandii, and Paenibacillus polymyxa have been successfully transferred and expressed in Escherichia coli, Saccharomyces cerevisiae, and even in the tobacco plant. These advances have laid the groundwork to enable cereal crops to "fix" nitrogen themselves to sustain their growth and yield.
Topics: Azotobacter vinelandii; Escherichia coli; Klebsiella oxytoca; Nitrogen Fixation; Paenibacillus polymyxa; Saccharomyces cerevisiae; Nicotiana
PubMed: 32009294
DOI: 10.1002/cbic.201900784 -
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 -
Journal of Applied Microbiology Dec 2021Paenibacillin is a naturally biosynthesized antimicrobial lantibiotic peptide which is produced by wild-type Paenibacillus polymyxa OSY-DF in low but detectable levels....
AIMS
Paenibacillin is a naturally biosynthesized antimicrobial lantibiotic peptide which is produced by wild-type Paenibacillus polymyxa OSY-DF in low but detectable levels. The aim was to increase paenibacillin titre and production consistency through sequential drug resistance screening.
METHODS AND RESULTS
Spontaneous mutants of P. polymyxa OSY-DF were isolated by subjecting the bacterium to two rounds of screening for resistance to rifampicin, which targets RNA polymerase, and gentamicin, which targets ribosomes. Changes in antimicrobial production of the mutants were monitored using a bioassay method. A spontaneous mutant, P. polymyxa OSY-EC, capable of producing high paenibacillin titre, was selected and compared phenotypically to the wild-type strain. The mutant was found to produce paenibacillin at five-fold higher titre than the wild type. The mutant constantly produced paenibacillin while the wild type produced the antimicrobial agent variably. Fourier transformation mid-infrared spectroscopy revealed an interclass distance of 6·4 between the wild type and the mutant strain, suggesting significant phenotypic change during the mutation.
CONCLUSIONS
P. polymyxa OSY-EC, a spontaneous mutant capable of consistent production of high paenibacillin titre, was isolated from the wild type after sequential screening on rationally selected antibiotics.
SIGNIFICANCE AND IMPACT OF THE STUDY
The study will help make paenibacillin available for large-scale testing by interested researchers and industries seeking applications that improve food safety and quality.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Bacteriocins; Drug Resistance; Paenibacillus polymyxa
PubMed: 34048127
DOI: 10.1111/jam.15165 -
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 -
Life Science Alliance Oct 2020is an agriculturally important plant growth-promoting rhizobacterium. Many species are known to be engaged in complex bacteria-bacteria and bacteria-host interactions,...
is an agriculturally important plant growth-promoting rhizobacterium. Many species are known to be engaged in complex bacteria-bacteria and bacteria-host interactions, which in other species were shown to necessitate quorum sensing communication. However, to date, no quorum sensing systems have been described in Here, we show that the type strain ATCC 842 encodes at least 16 peptide-based communication systems. Each of these systems is comprised of a pro-peptide that is secreted to the growth medium and processed to generate a mature short peptide. Each peptide has a cognate intracellular receptor of the RRNPP family, and we show that external addition of communication peptides leads to reprogramming of the transcriptional response. We found that these quorum sensing systems are conserved across hundreds of species belonging to the family, with some species encoding more than 25 different peptide-receptor pairs, representing a record number of quorum sensing systems encoded in a single genome.
Topics: Bacterial Proteins; Genome, Bacterial; Genomics; Paenibacillus; Paenibacillus polymyxa; Plant Development; Quorum Sensing
PubMed: 32764104
DOI: 10.26508/lsa.202000847 -
Plant Disease Mar 2024Strawberry is a popular fruit with valuable nutrition and an attractive fragrance, but its production and propagation are limited by various diseases, including...
Strawberry is a popular fruit with valuable nutrition and an attractive fragrance, but its production and propagation are limited by various diseases, including anthracnose and gray mold. For disease management, biological control measures are environmentally friendly and good alternatives to fungicides to avoid crop losses, reduce carbon emissions, and improve food safety. In this study, TP3, which originated from the strawberry phyllosphere, was shown to antagonize the anthracnose fungal pathogen and reduce leaf symptoms on strawberry plants. Several mass spectra corresponding to fusaricidin were detected in the confrontation assay of TP3 and by image mass spectrometry The transcription of and in the fusaricidin biosynthesis gene cluster increased while TP3 was cultured in the medium containing the culture filtrate of , as detected by reverse-transcription polymerase chain reaction, indicating the involvement of fusaricidins in TP3 antagonism against the anthracnose pathogen. Further disease control assays demonstrated the time frame and spatial mode of TP3-induced systemic resistance of strawberry against . The transcript level of the marker gene of the jasmonic acid pathway increased in strawberry leaves after drenching treatment with TP3, and the callose deposition was enhanced by further flg22 treatment. In addition, TP3 treatments of the strawberry mother plants reduced infection in the daughter plants, which would be a potent feature for the application of TP3 in strawberry nurseries and fields to reduce the impact of diseases, especially anthracnose.
Topics: Paenibacillus polymyxa; Fragaria; Fungicides, Industrial; Peptide Fragments; Thymopoietins
PubMed: 37580883
DOI: 10.1094/PDIS-08-23-1499-RE