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Microorganisms Jul 2023Causing major health and ecological disturbances, polychlorinated biphenyls (PCBs) are persistent organic pollutants still recovered all over the world. Microbial PCB...
Causing major health and ecological disturbances, polychlorinated biphenyls (PCBs) are persistent organic pollutants still recovered all over the world. Microbial PCB biotransformation is a promising technique for depollution, but the involved molecular mechanisms remain misunderstood. Ligninolytic enzymes are suspected to be involved in many PCB transformations, but their assessments remain scarce. To further inventory the capabilities of microbes to transform PCBs through their ligninolytic enzymes, we investigated the role of oxidase and peroxidase among a set of microorganisms isolated from a historically PCB-contaminated site. Among 29 isolated fungi and 17 bacteria, this work reports for the first time the PCB-transforming capabilities from fungi affiliated to , , , , , , and genera and bacteria affiliated to , , , , , sp., , and . In the same way, this is the first report of fungal isolates affiliated to the specie and genus that displayed oxidase (putatively laccase) and peroxidase activity, respectively, enhanced in the presence of PCBs (more than 4-fold and 20-fold, respectively, compared to controls). Based on these results, the observed activities are suspected to be involved in PCB transformation.
PubMed: 37630447
DOI: 10.3390/microorganisms11081887 -
Environmental Science & Technology Aug 2023Plant growth promoting rhizobacteria (PGPR) produce extracellular reactive oxygen species (ROS) to protect plants from external stresses. Fe-based nanomaterials can...
Plant growth promoting rhizobacteria (PGPR) produce extracellular reactive oxygen species (ROS) to protect plants from external stresses. Fe-based nanomaterials can potentially interact with PGPR and synergistically degrade organic pollutants, yet they have received no study. Here, we studied how the interaction between a typical PGPR (, JD37) and Fe-based nanomaterials facilitated the degradation of 2,4,4'-trichlorobiphenyl (PCB28), by comparing the zerovalent iron of 20 nm (nZVI), 100 nm (nZVI), and 5 μm; iron oxide nanomaterials (α-FeO, γ-FeO, and FeO) of ca. 20 nm; and ferrous and ferric salts. Although all Fe materials (0.1 g L) alone could not degrade aqueous PCB28 (0.1 mg L) under dark or aerobic conditions, nZVI, nZVI, α-FeO, and Fe promoted PCB28 degradation by JD37, with the half-life of PCB28 shortened from 16.5 h by JD37 alone to 8.1 h with nZVI cotreatment. Mechanistically, the nanomaterials stimulated JD37 to secrete phenazine-1-carboxylic acid and accelerated the NADH/NAD conversion, promoting O generation; JD37 increased Fe(II) dissolution from the nanomaterials, facilitating *OH generation; and the ROS gradually degraded PCB28 into benzoic acid through dihydroxy substitution, oxidation to quinone, and Michael addition. These findings provide a new strategy of nanoenabled biodegradation of organic pollutants by applying Fe-based nanomaterials and PGPR.
Topics: Polychlorinated Biphenyls; Reactive Oxygen Species; Iron; Nanostructures; Environmental Pollutants
PubMed: 37583057
DOI: 10.1021/acs.est.3c02495 -
World Journal of Microbiology &... Aug 2023Phenazines are heteroaromatic compounds consisting of a central pyrazine ring fused with two benzenes. Different functional groups attached to the dibenzopyrasin core...
Phenazines are heteroaromatic compounds consisting of a central pyrazine ring fused with two benzenes. Different functional groups attached to the dibenzopyrasin core cause differences in the chemical, physical, and biological properties of phenazines. Interest in these compounds has not diminished for decades. New biological activities and practical applications discovered in recent years force researchers to investigate all aspects of the synthesis, degradation, and mechanisms of action of phenazines. In this study, we have demonstrated the involvement of the coxA gene product (cytochrome c oxidase, su I) in the production of phenazines in P. chlororaphis subsp. aurantiaca. Overlap PCR was used to knock out the coxA gene and the resulting mutants were screened for their ability to grow on rich and minimal culture media and for phenazine production. The reintroduction of the full-length coxA gene into the B-162/coxA strains was used to further confirm the role of this gene product in the ability to produce phenazines. We were able to show that the product of the coxA gene is necessary for phenazine production in rich growth media. At the same time, the CoxA protein does not seem to have any effect on phenazine production in M9 minimal salt medium. We could show that knocking down even one subunit of the cytochrome c oxidase complex leads to a significant reduction (to trace concentrations) or complete suppression of phenazine antibiotic production on rich PCA medium in P. chlororaphis subsp. aurantiaca.
Topics: Electron Transport Complex IV; Pseudomonas; Phenazines; Bacterial Proteins
PubMed: 37583000
DOI: 10.1007/s11274-023-03685-2 -
Materials (Basel, Switzerland) Jul 2023Fibrous materials composed of core-sheath fibers from poly(ethylene oxide) (PEO), beeswax (BW) and 5-nitro-8-hydroxyquinoline (NQ) were prepared via the...
Fibrous materials composed of core-sheath fibers from poly(ethylene oxide) (PEO), beeswax (BW) and 5-nitro-8-hydroxyquinoline (NQ) were prepared via the self-organization of PEO and BW during the single-spinneret electrospinning of a homogeneous blend solution of the partners. Additionally, the application of the same approach enabled the preparation of fibrous materials composed of core-double sheath fibers from PEO, poly(L-lactide) (PLA) and NQ or 5-chloro-7-iodo-8-hydroxyquinoline (CQ), as well as from PEO, poly(ε-caprolactone) (PCL) and NQ. The consecutive selective extraction of BW and of the polyester with hexane and tetrahydrofuran, respectively, evidenced that core-double sheath fibers from PEO/polyester/BW/drug consisted of a PEO core, a polyester inner sheath and a BW outer sheath. In order to evaluate the possibility of the application of fibrous materials from PEO/BW/NQ, PEO/PLA/BW/NQ, PEO/PCL/BW/NQ and PEO/PLA/BW/CQ for plant protection, microbiological studies were performed using both phytopathogenic microorganisms (, and ) and beneficial microorganisms (, and ). It was found that the fibrous materials had anti-bacterial and anti-fungal activity against both phytopathogenic and beneficial microorganisms. This is the first report on the activity of fibrous materials loaded with 8-hydroxyquinoline derivatives not only against phytopathogenic but also against beneficial microorganisms that are of importance in agriculture.
PubMed: 37445197
DOI: 10.3390/ma16134882 -
Biotechnologia 2023Zinc is a vital micronutrient for all life forms, and Zn-solubilizing bacteria (ZSB) present in the soil convert inorganic zinc into forms available for plants. This...
Zinc is a vital micronutrient for all life forms, and Zn-solubilizing bacteria (ZSB) present in the soil convert inorganic zinc into forms available for plants. This study assessed ZSB isolated from cow dung for their plant growth-promoting (PGP) characteristics and potential to enhance tomato plant growth. The experiment assayed a total of 30 bacteria from cow dung for Zn-solubilization using insoluble ZnO and ZnCO. Atomic absorption spectroscopy quantitatively evaluated Zn-solubilization, and the isolates were further studied for Zn-solubilization and plant growth in . The CDS7 and CDS27 isolates were the most significant Zn-solubilizing strains. CDS7 exhibited increased ZnO solubility (32.1 mg/l) compared to CDS21 (23.7 mg/l). PGP trait quantitative results revealed that the CDS7 and CDS21 bacterial strains solubilized insoluble phosphate (287.2 and 217.7 μg/ml, respectively) and produced indole acetic acid (22.1 and 14.8 μg/ml, respectively). Based on 16S rRNA gene sequencing, CDS7 and CDS21 were identified as and , and 16S rDNA sequences were submitted to the GenBank database. Furthermore, ZSB strains were administered to tomato seeds under a pot study. The treatments with CDS7 inoculant and a consortium of both isolates were reported with maximum plant development (stem length 63.16 and 59.89 cm, respectively) and zinc content (3.13 and 2.36 mg/100 g, respectively) in tomato fruit compared to the control. In conclusion, microorganisms isolated from cow dung with PGP activity can improve Zn bioavailability and plant growth sustainably. They can be used as biofertilizers in agricultural fields to improve plant growth and production.
PubMed: 37427026
DOI: 10.5114/bta.2023.127205 -
Metabolic Engineering Jul 2023The emergence of next-generation sequencing (NGS) technologies has made it possible to not only sequence entire genomes, but also identify metabolic engineering targets...
The emergence of next-generation sequencing (NGS) technologies has made it possible to not only sequence entire genomes, but also identify metabolic engineering targets across the pangenome of a microbial population. This study leverages NGS data as well as existing molecular biology and bioinformatics tools to identify and validate genomic signatures for improving phenazine biosynthesis in Pseudomonas chlororaphis. We sequenced a diverse collection of 34 Pseudomonas isolates using short- and long-read sequencing techniques and assembled whole genomes using the NGS reads. In addition, we assayed three industrially relevant phenotypes (phenazine production, biofilm formation, and growth temperature) for these isolates in two different media conditions. We then provided the whole genomes and phenazine production data to a unitig-based microbial genome-wide association study (mGWAS) tool to identify novel genomic signatures responsible for phenazine production in P. chlororaphis. Post-processing of the mGWAS analysis results yielded 330 significant hits influencing the biosynthesis of one or more phenazine compounds. Based on a quantitative metric (called the phenotype score), we elucidated the most influential hits for phenazine production and experimentally validated them in vivo in the most optimal phenazine producing strain. Two genes significantly increased phenazine-1-carboxamide (PCN) production: a histidine transporter (ProY_1), and a putative carboxypeptidase (PS__04251). A putative MarR-family transcriptional regulator decreased PCN titer when overexpressed in a high PCN producing isolate. Overall, this work seeks to demonstrate the utility of a population genomics approach as an effective strategy in enabling the identification of targets for metabolic engineering of bioproduction hosts.
Topics: Pseudomonas chlororaphis; Metagenomics; Genome-Wide Association Study; Pseudomonas; Phenazines; Bacterial Proteins
PubMed: 37369325
DOI: 10.1016/j.ymben.2023.06.008 -
Letters in Applied Microbiology Jul 2023The use of microbial consortia has become a promising alternative for the management of various diseases. In this study, 18 artificial consortia were designed,...
The use of microbial consortia has become a promising alternative for the management of various diseases. In this study, 18 artificial consortia were designed, consisting of five bacteria, five fungi, and a mixture of five fungi and five bacteria; from a collection of microorganisms isolated from the rhizosphere of cape gooseberry plants grown in two soils potentially suppressive against Fusarium oxysporum. When evaluated under greenhouse conditions for their biocontrol activity on cape gooseberry plants, one consortium was selected for their high efficacy (over 90%) in the control of vascular wilt caused by F. oxysporum f. sp. physali. This was constituted by 10 microorganisms, the bacteria Paenibacillus peoriae, Bacillus subtilis, Lysinibacillus sp., B. simplex, and Pseudomonas chlororaphis; and the fungi Beauveria bassiana, Scopulariopsis brevicaulis, Trichoderma gamsii, T. ghanense, and T. lignicola. On the other hand, four of the consortia evaluated in the presence of the pathogen mitigated the deleterious effect produced by the pathogen on plant growth, expressing higher dry weights, both in the aerial and root parts. This work represents the first report on using these mixtures of microorganisms to control vascular wilt produced by F. oxysporum. However, further studies are needed to determine their activity in cape gooseberry fields.
Topics: Fusarium; Microbial Consortia; Ribes; Physalis; Bacillus subtilis; Fungi; Plant Diseases
PubMed: 37348479
DOI: 10.1093/lambio/ovad072 -
Journal of Agricultural and Food... Jun 2023Phenazine-1-carboxylic acid (PCA) secreted by has been commercialized and widely employed as an antifungal pesticide. However, it displays potential hazards to...
Phenazine-1-carboxylic acid (PCA) secreted by has been commercialized and widely employed as an antifungal pesticide. However, it displays potential hazards to nontarget microorganisms and the environment. Although the PCA degradation characteristics have received extensive attention, the biodegradation efficiency is still insufficient to address the environmental risks. In this study, an engineered capable of degrading PCA was constructed by introducing heterologous PCA 1,2-dioxygenase (PcaA1A2A3A4). By integrating the PCA degradation module in the chemical mutagenesis mutant P3, 7.94 g/L PCA can be degraded in 60 h, which exhibited the highest PCA degradation efficiency to date and was 35.4-fold higher than that of the PCA natural degraders. Additionally, PCA was converted to 1-methoxyphenazine through structure modification by introducing the functional enzymes PhzS and PhzM, which has good antifungal activity and environmental compatibility. This work demonstrates new possibilities for developing PCA-derived biopesticides and enables targeted control of the impact of PCA in diverse environments.
Topics: Pseudomonas chlororaphis; Antifungal Agents; Genetic Engineering; Phenazines; Bacterial Proteins
PubMed: 37247609
DOI: 10.1021/acs.jafc.3c01288 -
3 Biotech Jun 2023The recent advances in omics and computational analysis have enabled the capacity to identify the exclusive strain-specific metabolites and novel biosynthetic gene...
UNLABELLED
The recent advances in omics and computational analysis have enabled the capacity to identify the exclusive strain-specific metabolites and novel biosynthetic gene clusters. This study analyzed eight strains of including GS1, GS3, GS4, GS6, GS7, FS2, ARS38, PBSt2, one strain of RP4, one strain of (At1RP4), and one strain of (RS1) for the production of rhamnolipids, quorum-sensing signals, and osmolytes. Seven rhamnolipid derivatives were variably detected in fluorescent pseudomonads. These rhamnolipids included Rha-C-C, Rha-Rha-C-C, Rha-C-Cdb, Rha-C-C, Rha-Rha-C-C Rha-C-C, and Rha-Rha-C-Cdb. spp. also showed the variable production of osmoprotectants including N-acetyl glutaminyl glutamine amide (NAGGN), betaine, ectoine, and trehalose. Betaine and ectoine were produced by all pseudomonads, however, NAGGN and trehalose were observed by five and three strains, respectively. Four strains including (RP4), (At1RP4), (RS1), and (PBSt2) were exposed to 1- 4% NaCl concentrations and evaluated for the changes in phenazine production profile which were negligible. AntiSMASH 5.0 platform showed 50 biosynthetic gene clusters in PB-St2, of which 23 (45%) were classified as putative gene clusters with ClusterFinder algorithm, five (10%) were classified as non-ribosomal peptides synthetases (NRPS), five (10%) as saccharides, and four (8%) were classified as putative fatty acids. The genomic attributes and comprehensive insights into the metabolomic profile of these spp. strains showcase their phytostimulatory, phyto-protective, and osmoprotective effects of diverse crops grown in normal and saline soils.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s13205-023-03607-x.
PubMed: 37193329
DOI: 10.1007/s13205-023-03607-x -
Frontiers in Microbiology 2023Phenazine-1-carboxylic acid (PCA) is a biologically active substance with the ability to prevent and control crop diseases. It was certified as a pesticide by the...
Phenazine-1-carboxylic acid (PCA) is a biologically active substance with the ability to prevent and control crop diseases. It was certified as a pesticide by the Ministry of Agriculture of China in 2011 and was named "Shenzimycin." Lzh-T5 is a strain found in the rhizosphere of tomatoes. This strain can produce only 230 mg/L of PCA. We used LDA-4, which produces the phenazine synthetic intermediate trans-2,3-dihydro-3-hydroxyanthranilic acid in high amounts, as the starting strain. By restoring and knocking out , we achieved PCA accumulation. Moreover, PCA production was enhanced after knocking out negative regulators, enhancing the shikimate pathway, and performing fed-batch fermentation, thus resulting in the production of 10,653 mg/L of PCA. It suggested that Lzh-T5 has the potential to become an efficiency cell factory of biologically active substances.
PubMed: 37168109
DOI: 10.3389/fmicb.2023.1186052