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Journal of Hazardous Materials Sep 2023The presence of the sulfonic acid group in sulfonated anthraquinones (SAs) resulted in the difficulty in the mineralization of anthraquinone ring. Little information is...
The presence of the sulfonic acid group in sulfonated anthraquinones (SAs) resulted in the difficulty in the mineralization of anthraquinone ring. Little information is available on the removal pathway of the sulfonic acid group of SAs under aerobic/anaerobic conditions. Herein, sodium 1-aminoanthraquinone-2-sulfonate (ASA-2) was used as an important intermediate of SAs. A novel Pseudomonas nitroreducens WA capable of ASA-2 desulfonation was isolated from the Reactive Blue 19-degrading consortium WRB. Anaerobic desulfonation efficiency of 0.165 mM ASA-2 by strain WA reached 99% in 36 h at pH 7.5 and 35 ℃ using glucose as an electron donor. Further analysis showed that ASA-2 as an electron acceptor could be anaerobically transformed into 1-aminoanthraquinone and sulfite via the cleavage of C-S bond. Strain WA could also desulfonate sodium 1-amino-4-bromoanthraquinone-2-sulfonate and sodium anthraquinone-2-sulfonate. Under denitrification conditions, the formed sulfite could be oxidized to sulfate by nitrite via a chemical reaction, which was beneficial for nitrite removal. This phenomenon was observed in consortium WRB-amended system. Moreover, the consortium WRB could reduce the formed sulfite to sulfide due to the presence of Desulfovibrio. These results provide a theoretical basis for the anaerobic biodesulfonation of SAs along with nitrate removal and support for the development of sulfite-based biotechnology.
Topics: Nitrates; Sulfonic Acids; Nitrites; Anaerobiosis; Anthraquinones; Alkanesulfonates; Biotransformation; Sulfites; Denitrification
PubMed: 37348367
DOI: 10.1016/j.jhazmat.2023.131887 -
Frontiers in Microbiology 2023The root-knot nematodes (RKN), especially spp., are globally emerging harmful animals for many agricultural crops.
INTRODUCTION
The root-knot nematodes (RKN), especially spp., are globally emerging harmful animals for many agricultural crops.
METHODS
To explore microbial agents for biological control of these nematodes, the microbial communities of the rhizosphere soils and roots of sponge gourd () infected and non-infected by nematodes, were investigated using culture-dependent and -independent methods.
RESULTS
Thirty-two culturable bacterial and eight fungal species, along with 10,561 bacterial and 2,427 fungal operational taxonomic units (OTUs), were identified. Nine culturable bacterial species, 955 bacterial and 701 fungal OTUs were shared in both four groups. More culturable bacterial and fungal isolates were detected from the uninfected soils and roots than from the infected soils and roots (except no fungi detected from the uninfected roots), and among all samples, nine bacterial species ( sp., sp., , Enterobacteriaceae sp., , sp., Micrococcaceae sp., Rhizobiaceae sp., and sp.) were shared, with sp. and sp. being dominant. was exclusively present in the infested soils, while , , and sp., together with , sp., , and sp. were found only in the uninfected soils. , sp., , and sp. were only in the uninfected roots while sp. only in infected roots. After infestation, 319 bacterial OTUs (such as ) and 171 fungal OTUs (such as ) were increased in rhizosphere soils, while 181 bacterial OTUs (such as ) and 166 fungal OTUs (such as ) rose their abundance in plant roots. Meanwhile, much more decreased bacterial or fungal OTUs were identified from rhizosphere soils rather than from plant roots, exhibiting the protective effects of host plant on endophytes. Among the detected bacterial isolates, sp. TR27 was discovered to exhibit nematocidal activity, and , sp. P35, and to show repellent potentials for the second stage juveniles, which can be used to develop RKN bio-control agents.
DISCUSSION
These findings provided insights into the interactions among root-knot nematodes, host plants, and microorganisms, which will inspire explorations of novel nematicides.
PubMed: 37303801
DOI: 10.3389/fmicb.2023.1168179 -
Microbiology (Reading, England) Jan 2020Azelaic acid is a dicarboxylic acid that has recently been shown to play a role in plant-bacteria signalling and also occurs naturally in several cereals. Several...
Azelaic acid is a dicarboxylic acid that has recently been shown to play a role in plant-bacteria signalling and also occurs naturally in several cereals. Several bacteria have been reported to be able to utilize azelaic acid as a unique source of carbon and energy, including . In this study, we utilize as a model organism to study bacterial degradation of and response to azelaic acid. We report genetic evidence of azelaic acid degradation and the identification of a transcriptional regulator that responds to azelaic acid in DSM 9128. Three mutants possessing transposons in genes of an acyl-CoA ligase, an acyl-CoA dehydrogenase and an isocitrate lyase display a deficient ability in growing in azelaic acid. Studies on transcriptional regulation of these genes resulted in the identification of an IclR family repressor that we designated as AzeR, which specifically responds to azelaic acid. A bioinformatics survey reveals that AzeR is confined to a few proteobacterial genera that are likely to be able to degrade and utilize azelaic acid as the sole source of carbon and energy.
Topics: Bacteria; Bacterial Proteins; Dicarboxylic Acids; Gene Expression Regulation, Bacterial; Molecular Structure; Mutation; Phylogeny; Promoter Regions, Genetic; Pseudomonas; Repressor Proteins; Transcription Factors
PubMed: 31621557
DOI: 10.1099/mic.0.000865 -
Current Microbiology Feb 2022Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study...
Production of fuels from renewable resources is of utmost importance due to fast depletion of fossil resources and related environmental issues. The present study explored the intrinsic capability of microbial strains to produce alka(e)nes, the next-generation biofuel, thus to reduce the dependence upon current petroleum fuels. Eight bacterial strains, namely, SDK-1, SDK-2, SDK-6, SDK-7, SDK-8, SDK-9, SDK-10, and SDK-11 were isolated from sludge and soil samples collected from different sources using lauric acid as a substrate with a potential to produce alka(e)nes. Production of different medium- and long-chain alka(e)nes by these isolates was confirmed via gas chromatography-mass spectrometer (GC-MS) analysis. SDK-1 (7.2%), SDK-2 (3.72%), and SDK-6 (3.52%) produced significant proportion of medium-chain hydrocarbons as compared to SDK-10 and control with no production. These isolates may be further investigated for production of these alternative sources of energy. In contrary, maximum fraction of long-chain hydrocarbons is produced in SDK-8 (75.28%) followed by SDK-9 (61.51%). Similarly more than 50% of the total hydrocarbons produced in SDK-8 constitute fossil mimic hydrocarbons while only 10.78% fractions were found in SDK-10. Since these fractions resemble different hydrocarbons obtained from crude oil, hence may be explored for their wide applications in different fields. Biochemical characterization and sequencing of the 16S rRNA gene revealed the homology of SDK-1, SDK-2 and SDK-6 with Pseudomonas aeruginosa, SDK-7 and SDK-9 with Enterobacter cloacae, SDK-8 with Klebsiella pnuemoniae, SDK-10 with Enterobacter hormaechei and SDK-11 with Pseudomonas nitroreducens, respectively.
Topics: Bacteria; Biodegradation, Environmental; Biofuels; Hydrocarbons; Petroleum; RNA, Ribosomal, 16S
PubMed: 35129690
DOI: 10.1007/s00284-022-02781-0 -
ACS Biomaterials Science & Engineering Jan 2020Silver nanocrystals have been successfully fabricated by the bioreduction route using the ethanolic extract of (neem) leaves as the reducing and capping agent without...
Silver nanocrystals have been successfully fabricated by the bioreduction route using the ethanolic extract of (neem) leaves as the reducing and capping agent without solvent interference. The silver nanocrystals were grown in a single-step method, without the influence of external energy or surfactants, and at room temperature. The nanoparticles were prepared from different ratios of silver ions to reducing agent molecules and were characterized by UV-vis spectroscopy and transmission electron microscopy (TEM). The nanoparticles were roughly spherical and polydispersed with diameters of less than 40 nm, as determined with high-resolution transmission electron microscopy (HRTEM). Fast Fourier transform (FFT) analysis and X-ray diffraction (XRD) analysis elucidated the crystalline nature of the nanoparticles. The presence of participating functional groups was determined with Fourier transform infrared (FTIR) spectroscopy. The synthesized silver nanoparticles were analyzed as a potential surface-enhanced Raman spectroscopy (SERS) substrate by incorporating rhodamine B as the Raman reporter molecule. The bioreduction process was monitored through SERS fingerprint, which was evaluated by the change in vibrational energies of metal-ligand bonds. It was possible to detect the SERS spectral pattern of the probe molecules on the Ag nanoparticles without the use of any aggregating agent. Thus, the formation of probable intra- and interparticle hot spots was attributed to evaporation-induced aggregation. Furthermore, stirring and precursor salt concentration influenced the kinetics involved in the fabrication process. The thermal stability of the lyophilized nanoparticles prepared from 0.1 M AgNO was evaluated with thermogravimetric analysis (TGA) and had a residual mass of 60% at 600 °C. X-ray photoelectron spectroscopy (XPS) studies were used to validate the compositional and chemical-state information. The biomass-capped silver nanoparticles provided antimicrobial activity by inhibiting the growth of , a biofilm-forming bacterium, and the fungus, (NII 08123).
Topics: Anti-Infective Agents; Aspergillus; Metal Nanoparticles; Plant Extracts; Pseudomonas; Silver
PubMed: 33463216
DOI: 10.1021/acsbiomaterials.9b01257 -
BMJ Case Reports May 2021A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage...
A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage fluid collected during a repeat bronchoscopy were initially identified as by VITEK-2 and mass spectrometry platforms. Whole-genome sequencing, however, subsequently demonstrated that the bacteria were , representing the first known case of cultured from human lungs.
Topics: Bronchoalveolar Lavage Fluid; Humans; Lung; Male; Pneumonia; Pseudomonas; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 34031078
DOI: 10.1136/bcr-2020-241327 -
Frontiers in Microbiology 2022Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However,...
Electrified biotrickling filters represent sustainable microbial electrochemical technology for treating organic carbon-deficient ammonium-contaminated waters. However, information on the microbiome of the conductive granule bed cathode remains inexistent. For uncovering this black box and for identifying key process parameters, minimally invasive sampling units were introduced, allowing for the extraction of granules from different reactor layers during reactor operation. Sampled granules were analyzed using cyclic voltammetry and molecular biological tools. Two main redox sites [-288 ± 18 mV and -206 ± 21 mV vs. standard hydrogen electrode (SHE)] related to bioelectrochemical denitrification were identified, exhibiting high activity in a broad pH range (pH 6-10). A genome-centric analysis revealed a complex nitrogen food web and the presence of typical denitrifiers like and with none of these species being identified as electroactive microorganism so far. These are the first results to provide insights into microbial structure-function relationships within electrified biotrickling filters and underline the robustness and application potential of bioelectrochemical denitrification for environmental remediation.
PubMed: 35711746
DOI: 10.3389/fmicb.2022.869474 -
Applied and Environmental Microbiology Aug 2020The enzymatic production of 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) has gained interest in recent years, as FDCA is a renewable precursor of...
The enzymatic production of 2,5-furandicarboxylic acid (FDCA) from 5-hydroxymethylfurfural (HMF) has gained interest in recent years, as FDCA is a renewable precursor of poly(ethylene-2,5-furandicarboxylate) (PEF). 5-Hydroxymethylfurfural oxidases (HMFOs) form a flavoenzyme family with genes annotated in a dozen bacterial species but only one enzyme purified and characterized to date (after heterologous expression of a sp. HMFO gene). This oxidase acts on both furfuryl alcohols and aldehydes and, therefore, is able to catalyze the conversion of HMF into FDCA through 2,5-diformylfuran (DFF) and 2,5-formylfurancarboxylic acid (FFCA), with only the need of oxygen as a cosubstrate. To enlarge the repertoire of HMFO enzymes available, genetic databases were screened for putative HMFO genes, followed by heterologous expression in After unsuccessful trials with other bacterial HMFO genes, HMFOs from two species were produced as active soluble enzymes, purified, and characterized. The sp. enzyme was also produced and purified in parallel for comparison. Enzyme stability against temperature, pH, and hydrogen peroxide, three key aspects for application, were evaluated (together with optimal conditions for activity), revealing differences between the three HMFOs. Also, the kinetic parameters for HMF, DFF, and FFCA oxidation were determined, the new HMFOs having higher efficiencies for the oxidation of FFCA, which constitutes the bottleneck in the enzymatic route for FDCA production. These results were used to set up the best conditions for FDCA production by each enzyme, attaining a compromise between optimal activity and half-life under different conditions of operation. HMFO is the only enzyme described to date that can catalyze by itself the three consecutive oxidation steps to produce FDCA from HMF. Unfortunately, only one HMFO enzyme is currently available for biotechnological application. This availability is enlarged here by the identification, heterologous production, purification, and characterization of two new HMFOs, one from and one from an unidentified species. Compared to the previously known HMFO, the new enzyme from exhibits better performance for FDCA production in wider pH and temperature ranges, with higher tolerance for the hydrogen peroxide formed, longer half-life during oxidation, and higher yield and total turnover numbers in long-term conversions under optimized conditions. All these features are relevant properties for the industrial production of FDCA. In summary, gene screening and heterologous expression can facilitate the selection and improvement of HMFO enzymes as biocatalysts for the enzymatic synthesis of renewable building blocks in the production of bioplastics.
Topics: Bacterial Proteins; Dicarboxylic Acids; Escherichia coli; Furaldehyde; Furans; Methylophilaceae; Microorganisms, Genetically-Modified; Oxidoreductases; Pseudomonas
PubMed: 32503910
DOI: 10.1128/AEM.00842-20 -
International Journal of Systematic and... Feb 2021A Gram-stain-negative, aerobic, motile, short-rod-shaped bacterium with nicosulfuron-degrading ability, designated strain LAM1902, was isolated from a microbial...
A Gram-stain-negative, aerobic, motile, short-rod-shaped bacterium with nicosulfuron-degrading ability, designated strain LAM1902, was isolated from a microbial consortium enriched with nicosulfuron as a sole nitrogen and energy source. The optimal temperature and pH for growth of strain LAM1902 were 30 °C and pH 6.0, respectively. Strain LAM1902 could grow in the presence of NaCl with concentration up to 4.0 % (w/v). Comparative analysis of 16S rRNA gene sequences revealed that LAM1902 was closely related to the members of the family to the genus , with the highest similarity to DSM 14399 (99.6 %), WZBFD3-5A2 (99.3 %) and Esp-1 (98.8 %). Multi-locus sequence analysis based on both concatenated sequences of the 16S rRNA gene and three housekeeping genes (, and ) further confirmed the intrageneric phylogenetic position of strain LAM1902. The genomic DNA G+C content of LAM1902 was 64.8 mol%. The low values of DNA-DNA hybridization (less than 43.7 %) and average nucleotide identity (less than 90.9 %) also showed that the strain was distinctly different from known species of the genus . The major fatty acids were C, C cyclo and anteiso C. Ubiquinone Q-9 was detected as the predorminant respiratory quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and aminophospholipid. Based on phylogenetic, phenotypic and chemotaxonomic analyses and genome comparisons, we conclude that strain LAM1902 represents a novel species, for which the name sp. nov. is proposed. The type strain is LAM1902 (=JCM 33860=KCTC 72830).
Topics: Bacterial Typing Techniques; Base Composition; DNA, Bacterial; Fatty Acids; Genes, Bacterial; Microbial Consortia; Phospholipids; Phylogeny; Pseudomonas; Pyridines; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sulfonylurea Compounds; Ubiquinone
PubMed: 33411665
DOI: 10.1099/ijsem.0.004632 -
Applied Biochemistry and Biotechnology Apr 2021Currently, the biotechnological preparation of fragrances using natural materials attracted growing attention. Enzymatic synthesis of vanillin from isoeugenol by...
Currently, the biotechnological preparation of fragrances using natural materials attracted growing attention. Enzymatic synthesis of vanillin from isoeugenol by recombinant isoeugenol monooxygenase from Pseudomonas nitroreducens Jin1 was systematically investigated herein. With series of work on the construction of recombinant E. coli over-expressing isoeugenol monooxygenase, optimization of the culture conditions for enzyme production and reaction process for converting isoeugenol into vanillin, an increase of 22-fold in the enzyme activity (2050 U/L) was obtained, and the conversion was significantly increased at high substrate concentration with the aid of magnetic chitosan membrane for product isolation in situ. Under optimal conditions, the product concentration and space-time yield reached 252 mM and 115 g/L/d, respectively, and vanillin was obtained in 82.3% yield and > 99% purity in the gram preparative scale. The developed bioprocess showed application potential for efficient preparation of vanillin from inexpensive natural resources.
Topics: Bacterial Proteins; Benzaldehydes; Eugenol; Mixed Function Oxygenases; Pseudomonas; Recombinant Proteins
PubMed: 33411131
DOI: 10.1007/s12010-020-03478-5