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Frontiers in Microbiology 2023Fusaricidin, a lipopeptide antibiotic, is specifically produced by strains, which could strongly inhibit fungi. Fusaricidin bio-synthetase A (FusA) is composed of six...
Fusaricidin, a lipopeptide antibiotic, is specifically produced by strains, which could strongly inhibit fungi. Fusaricidin bio-synthetase A (FusA) is composed of six modules and is essential for synthesizing the peptide moiety of fusaricidin. In this study, we confirmed the FusA of strain WLY78 involved in producing Fusaricidin LI-F07a. We constructed six engineered strains by deletion of each module within FusA from the genome of strain WLY78. One of the engineered strains is able to produce a novel compound that exhibits better antifungal activity than that of fusaricidin LI-F07a. This new compound, known as fusaricidin [ΔAla] LI-F07a, has a molecular weight of 858. Our findings reveal that it exhibits a remarkable 1-fold increase in antifungal activity compared to previous fusaricidin, and the fermentation yield reaches ~55 mg/L. This research holds promising implications for plant protection against infections caused by and pathogen infection.
PubMed: 37822742
DOI: 10.3389/fmicb.2023.1239958 -
Frontiers in Microbiology 2024L. is a versatile edible plant that is widely explored due to its medicinal properties and as a key element in intercropping systems. Its growth could be improved by...
L. is a versatile edible plant that is widely explored due to its medicinal properties and as a key element in intercropping systems. Its growth could be improved by the use of biofertilizers that can enhance nutrient uptake by the plant or provide tolerance to different abiotic and biotic stresses. In a previous study, 101 endophytes isolated from roots showed more than three plant growth-promoting (PGP) features , such as phosphate mineralization/solubilization, production of siderophores, antimicrobial substances and indole-related compounds, and presence of the gene. To provide sustainable alternatives for biofertilization, the genomes of two promising endophytes-CAPE95 and CAPE238-were sequenced to uncover metabolic pathways related to biofertilization. Greenhouse experiments were conducted with 216 seeds and 60 seedlings, half co-inoculated with the endophytes (treatment) and half inoculated with 1X PBS (control), and the impact of the co-inoculation on the plant's bacteriome was accessed through 16S rRNA gene metabarcoding. The strains CAPE95 and CAPE238 were taxonomically assigned as and , respectively. Metabolic pathways related to the enhancement of nutrient availability (nitrogen fixation, sulfate-sulfur assimilation), biosynthesis of phytohormones (indole-3-acetic acid precursors) and antimicrobial substances (bacilysin, paenibacillin) were found in their genomes. The experiments showed that treated seeds exhibited faster germination, with a 20.3% higher germination index than the control on the eleventh day of the experiment. Additionally, treated seedlings showed significantly higher plant height and leaf diameters ( < 0.05). The bacterial community of the treated plants was significantly different from that of the control plants ( < 0.001) and showed a higher richness and diversity of species (Chao and Shannon indexes, < 0.001). A higher relative abundance of potential synergistic PGP bacteria was also shown in the bacteriome of the treated plants, such as and . For the first time, co-inoculation of and was shown to have great potential for application as a biofertilizer to plants. The bacterial consortium used here could also be explored in other plant species in the future.
PubMed: 38585693
DOI: 10.3389/fmicb.2024.1356891 -
ACS Infectious Diseases Apr 2024The polymyxins are nonribosomal lipopeptides produced by and are potent antibiotics with activity specifically directed against Gram-negative bacteria. While the... (Review)
Review
The polymyxins are nonribosomal lipopeptides produced by and are potent antibiotics with activity specifically directed against Gram-negative bacteria. While the clinical use of polymyxins has historically been limited due to their toxicity, their use is on the rise given the lack of alternative treatment options for infections due to multidrug resistant Gram-negative pathogens. The Gram-negative specificity of the polymyxins is due to their ability to target lipid A, the membrane embedded LPS anchor that decorates the cell surface of Gram-negative bacteria. Notably, the mechanisms responsible for polymyxin toxicity, and in particular their nephrotoxicity, are only partially understood with most insights coming from studies carried out in the past decade. In parallel, many synthetic and semisynthetic polymyxin analogues have been developed in recent years in an attempt to mitigate the nephrotoxicity of the natural products. Despite these efforts, to date, no polymyxin analogues have gained clinical approval. This may soon change, however, as at the moment there are three novel polymyxin analogues in clinical trials. In this context, this review provides an update of the most recent insights with regard to the structure-activity relationships and nephrotoxicity of new polymyxin variants reported since 2010. We also discuss advances in the synthetic methods used to generate new polymyxin analogues, both via total synthesis and semisynthesis.
Topics: Anti-Bacterial Agents; Polymyxins; Lipopeptides; Gram-Negative Bacteria; Structure-Activity Relationship
PubMed: 38470446
DOI: 10.1021/acsinfecdis.3c00630 -
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 -
Microbiology (Reading, England) Jul 2023Over the past decades, antibiotic resistance has become a major clinical problem, and searching for new therapeutic strategies seems to be necessary. Using novel natural...
Over the past decades, antibiotic resistance has become a major clinical problem, and searching for new therapeutic strategies seems to be necessary. Using novel natural compounds, antimicrobial peptides, and bacteriophages is the most promising solution. In this study, various cationic metabolite-producer bacteria were isolated from different soil samples. Two isolates were identified as HS4 (accession number: MW791428) and HS5 (accession number: MW791430) based on biochemical characteristics and phylogenetic analysis using 16S rRNA gene sequences. The cationic compound in the fermentation broth was precipitated and purified with sodium tetraphenylborate salt. The purified cationic peptide was confirmed to be epsilon-poly-l-lysine by structural and molecular analysis using High-Performance Liquid Chromatography, Sodium dodecyl-sulfate-polyacrylamide gel electrophoresis, and Fourier-transform infrared spectroscopy. The antibacterial activity of epsilon-poly-l-lysine was evaluated against ATCC 25923, ATCC 25922, ATCC 29212, ATCC 13880, and ATCC 13883 by microdilution method. Furthermore, the antibacterial effects of purified epsilon-poly-l-lysine in combination with two long non-contractile tail bacteriophages against vancomycin-resistant and colistin-resistant were investigated. The results indicated great antibacterial activity of epsilon-poly-l-lysine which was produced by two novel bacteria. The epsilon-poly-l-lysine as a potent cationic antimicrobial peptide is demonstrated to possess great antimicrobial activity against pathogenic and also antibiotic-resistant bacteria.
Topics: Polylysine; Stenotrophomonas maltophilia; Paenibacillus polymyxa; RNA, Ribosomal, 16S; Phylogeny; Anti-Bacterial Agents; Bacteria; Antimicrobial Cationic Peptides; Microbial Sensitivity Tests
PubMed: 37477972
DOI: 10.1099/mic.0.001363 -
Microbiology Resource Announcements Nov 2023Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as , while the remaining four were unique representatives of , , , and...
Here, we report 10 distinct bacterial genomes from Amazonian dark earths, including six identified as , while the remaining four were unique representatives of , , , and sp., respectively. Each strain exhibited antagonistic activity against , underscoring their potential as sustainable agriculture resources.
PubMed: 37811974
DOI: 10.1128/MRA.00574-23 -
BMC Biotechnology Jul 2023One critical parameter in microbial cultivations is the composition of the cultivation medium. Nowadays, the application of chemically defined media increases, due to a...
BACKGROUND
One critical parameter in microbial cultivations is the composition of the cultivation medium. Nowadays, the application of chemically defined media increases, due to a more defined and reproducible fermentation performance than in complex media. In order, to improve cost-effectiveness of fermentation processes using chemically defined media, the media should not contain nutrients in large excess. Additionally, to obtain high product yields, the nutrient concentrations should not be limiting. Therefore, efficient medium optimization techniques are required which adapt medium compositions to the specific nutrient requirements of microorganisms.
RESULTS
Since most Paenibacillus cultivation protocols so far described in literature are based on complex ingredients, in this study, a chemically defined medium for an industrially relevant Paenibacillus polymyxa strain was developed. A recently reported method, which combines a systematic experimental procedure in combination with online monitoring of the respiration activity, was applied and extended to identify growth limitations for Paenibacillus polymyxa. All cultivations were performed in microtiter plates. By systematically increasing the concentrations of different nutrient groups, nicotinic acid was identified as a growth-limiting component. Additionally, an insufficient buffer capacity was observed. After optimizing the growth in the chemically defined medium, the medium components were systematically reduced to contain only nutrients relevant for growth. Vitamins were reduced to nicotinic acid and biotin, and amino acids to methionine, histidine, proline, arginine, and glutamate. Nucleobases/-sides could be completely left out of the medium. Finally, the cultivation in the reduced medium was reproduced in a laboratory fermenter.
CONCLUSION
In this study, a reliable and time-efficient high-throughput methodology was extended to investigate limitations in chemically defined media. The interpretation of online measured respiration activities agreed well with the growth performance of samples measured in parallel via offline analyses. Furthermore, the cultivation in microtiter plates was validated in a laboratory fermenter. The results underline the benefits of online monitoring of the respiration activity already in the early stages of process development, to avoid limitations of medium components, oxygen limitation and pH inhibition during the scale-up.
Topics: Paenibacillus polymyxa; Bioreactors; Fermentation; Paenibacillus; Culture Media; Nicotinic Acids
PubMed: 37507713
DOI: 10.1186/s12896-023-00793-7 -
Microbiology Spectrum Jan 2024Polymyxins are considered the last line of defense against multidrug-resistant bacteria. The regulatory mechanism of polymyxin synthesis is poorly studied in . In this...
Polymyxins are considered the last line of defense against multidrug-resistant bacteria. The regulatory mechanism of polymyxin synthesis is poorly studied in . In this study, we found that Abh and AbrB3 negatively regulated, whereas Spo0A positively regulated polymyxin synthesis in SC2. In addition, a regulatory relationship between Abh, AbrB3, and Spo0A was revealed, which regulate polymyxin synthesis via multiple regulatory mechanisms in .
Topics: Polymyxins; Paenibacillus polymyxa; Paenibacillus
PubMed: 38054717
DOI: 10.1128/spectrum.02293-23 -
Synthetic and Systems Biotechnology Mar 2024Polymyxin B, produced by is used as the last line of defense clinically. In this study, exogenous mixture of precursor amino acids increased the level and proportion of...
Polymyxin B, produced by is used as the last line of defense clinically. In this study, exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of polymyxin B analogs of CJX518-AC (PPAC) from 0.15 g/L and 61.8 % to 0.33 g/L and 79.9 %, respectively. The co-culture of strain PPAC and recombinant -leu01, which produces high levels of threonine, leucine, and isoleucine, increased polymyxin B1 production to 0.64 g/L. When strains PPAC and -leu01 simultaneously inoculated into an optimized medium with 20 g/L peptone, polymyxin B1 production was increased to 0.97 g/L. Furthermore, the polymyxin B1 production in the co-culture of strains PPAC and -leu01 increased to 2.21 g/L after optimized inoculation ratios and fermentation medium with 60 g/L peptone. This study provides a new strategy to improve polymyxin B1 production.
PubMed: 38348399
DOI: 10.1016/j.synbio.2024.01.015 -
Scientific Reports Jan 2024Accurate identification and typing of microbes are crucial steps in gaining an awareness of the biological heterogeneity and reliability of microbial material within any...
Accurate identification and typing of microbes are crucial steps in gaining an awareness of the biological heterogeneity and reliability of microbial material within any proprietary or public collection. Paenibacillus polymyxa is a bacterial species of great agricultural and industrial importance due to its plant growth-promoting activities and production of several relevant secondary metabolites. In recent years, matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used as an alternative rapid tool for identifying, typing, and differentiating closely related strains. In this study, we investigated the diversity of three P. polymyxa strains. The mass spectra of ATCC 842, DSM 292, and DSM 365 were obtained, analysed, and compared to select discriminant peaks using ClinProTools software and generate classification models. MALDI-TOF MS analysis showed inconsistent results in identifying DSM 292 and DSM 365 as belonging to P. polimixa species, and comparative analysis of mass spectra revealed the presence of highly discriminatory biomarkers among the three strains. 16S rRNA sequencing and Average Nucleotide Identity (ANI) confirmed the discrepancies found in the proteomic analysis. The case study presented here suggests the enormous potential of the proteomic-based approach, combined with statistical tools, to predict and explore differences between closely related strains in large microbial datasets.
Topics: Paenibacillus polymyxa; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Proteomics; RNA, Ribosomal, 16S; Reproducibility of Results
PubMed: 38297004
DOI: 10.1038/s41598-023-50010-w