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The Analyst Jul 2023Phosphite, the anion of phosphorus acid, is an important metabolite in the global biogeochemical phosphorus cycle and a phosphorus species with unique agricultural...
Phosphite, the anion of phosphorus acid, is an important metabolite in the global biogeochemical phosphorus cycle and a phosphorus species with unique agricultural properties. As such, methods for detecting phosphite quantitatively and selectively are critical to evidencing phosphorus redox chemistry. Here, we present a fluorescence-based assay for phosphite, utilizing the NAD-dependent oxidation of phosphite by phosphite dehydrogenase and the subsequent reduction of resazurin to resorufin. With the application of a thermostable phosphite dehydrogenase, a medium-invariant analytical approach, and novel sample preparation methods, the assay is capable of rapid and accurate phosphite quantification with a 3 μM limit of detection in a wide array of biologically- and environmentally-relevant matrices, including bacterial and archaeal cell lysate, seawater, anaerobic digester sludge, and plant tissue. We demonstrate the utility of the assay by quantitating phosphite uptake in a model crop plant in the presence or absence of a phosphite-oxidising strain of as a soil additive, establishing this bacterium as an efficient phosphite converting biofertilizer.
Topics: Phosphites; Bacteria; Oxidation-Reduction; Phosphorus
PubMed: 37424451
DOI: 10.1039/d3an00575e -
Journal of Hazardous Materials Sep 2023In the study, we investigated the different compositions of biochar-derived dissolved organic matter (BDOM) that play a key role in the biodegradation of...
In the study, we investigated the different compositions of biochar-derived dissolved organic matter (BDOM) that play a key role in the biodegradation of sulfamethoxazole (SMX) and chloramphenicol (CAP) by P. stutzeri and S. putrefaciens, and found that aliphatic compounds in Group 4, fulvic acid like in Region III, and solid microbial byproduct like in region IV are key common factors. The growth and antibiotic degradation efficiency of P. stutzeri and S. putrefaciens are positively correlated with the content of Group 4 and Region III, and negatively correlated with Region IV. This is consistent with the optimal biodegradation results of BDOM700 with the highest content of Group 4 and Region III. Additionally, the degradation efficiency of SMX by Pseudomonas stutzeri is negatively correlated with the percentage of polycyclic aromatics in Group 1, but not with CAP. Similarly, the percentage of fatty acids in S. putrefaciens was positively correlated with Group 1, whereas P. stutzeri did not. This indicates that some components of BDOM have varying effects on different bacteria or types of antibiotics. This study provides new insights into enhancing antibiotic biodegradation by controlling the composition of BDOM.
Topics: Sulfamethoxazole; Chloramphenicol; Biodegradation, Environmental; Anti-Bacterial Agents
PubMed: 37423136
DOI: 10.1016/j.jhazmat.2023.131979 -
Biodegradation Dec 2023At present, cometabolic degradation is an extensive method for the biological removal of high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) in the marine...
At present, cometabolic degradation is an extensive method for the biological removal of high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) in the marine environment. However, due to the refractory to degradation and high toxicity, there are few studies on pyrene (PYR) cometabolic degradation with phenanthrene (PHE) as substrate. In this study, a Pseudomonas stutzeri DJP1 strain isolated from sediments was used in the cometabolic system of PHE and PYR. The biomass and the activity of key enzymes such as dehydrogenase and catechol 12 dioxygenase of strain were improved, but the enhancement of biotoxicity resulted in the inhibition of cometabolism simultaneously. Seven metabolites were identified respectively in PYR, PHE degradation cultures. It was speculated that the cometabolism of PHE and PYR had a common phthalic acid pathway, and the degradation pathway of PHE was included in the downstream pathway of PYR. The functional genes such as PhdF, NidD and CatA involved in DJP1 degradation were revealed by Genome analysis. This study provides a reference for the biodegradation of PYR and PHE in real marine environment.
Topics: Pseudomonas stutzeri; Phenanthrenes; Polycyclic Aromatic Hydrocarbons; Pyrenes; Biodegradation, Environmental
PubMed: 37354271
DOI: 10.1007/s10532-023-10035-4 -
Chemosphere Sep 2023The potential effects of engineered metal oxide nanoparticles (MONPs) on bacterial nitrogen fixation are of great concern. Herein, the impact and mechanism of the...
The potential effects of engineered metal oxide nanoparticles (MONPs) on bacterial nitrogen fixation are of great concern. Herein, the impact and mechanism of the increasing-used MONPs, including TiO, AlO, and ZnO nanoparticles (TiONP, AlONP, and ZnONP, respectively), on nitrogenase activity was studied at the concentrations ranging from 0 to 10 mg L using associative rhizosphere nitrogen-fixing bacteria Pseudomonas stutzeri A1501. Nitrogen fixation capacity was inhibited by MONPs in an increasing degree of TiONP < AlONP < ZnONP. Realtime qPCR analysis showed that the expressions of nitrogenase synthesis-related genes, including nifA and nifH, were inhibited significantly when MONPs were added. MONPs could cause the explosion of intracellular ROS, and ROS not only changed the permeability of the membrane but also inhibited the expression of nifA and biofilm formation on the root surface. The repressed nifA gene could inhibit transcriptional activation of nif-specific genes, and ROS reduced the biofilm formation on the root surface which had a negative effect on resisting environmental stress. This study demonstrated that MONPs, including TiONP, AlONP, and ZnONP, inhibited bacterial biofilm formation and nitrogen fixation in the rice rhizosphere, which might have a negative effect on the nitrogen cycle in bacteria-rice system.
Topics: Nitrogen Fixation; Pseudomonas stutzeri; Reactive Oxygen Species; Nitrogen-Fixing Bacteria; Rhizosphere; Oxides; Nitrogenase; Nanoparticles; Bacterial Proteins; Nitrogen
PubMed: 37327828
DOI: 10.1016/j.chemosphere.2023.139223 -
Journal of Hazardous Materials Sep 2023Microplastics (MPs) are emerging pollutants. Landfills store up to 42% of worldwide plastic waste and serve as an important source of MPs. However, the study of MPs...
A landfill serves as a critical source of microplastic pollution and harbors diverse plastic biodegradation microbial species and enzymes: Study in large-scale landfills, China.
Microplastics (MPs) are emerging pollutants. Landfills store up to 42% of worldwide plastic waste and serve as an important source of MPs. However, the study of MPs distribution and the plastic biodegradation potential in landfills is limited. In this study, the distribution of abundance, size, morphology and polymer type of MPs and plastics biodegradation species in refuse samples along landfill depths were extensively investigated within a large-scale landfill in Shenzhen, China. In addition, plastics biodegradation enzymes were evaluated in seven Chinese large-scale landfills leachate. MPs distribution pattern was investigated in all refuse samples. The abundance of MPs in refuse samples varied between 81 and 133 items/g. The size of MPs in all samples varied between 0.03 and 5 mm, and the average sizes were 1.2 mm ± 0.1 mm. The main morphology and polymer type were fragments and cellophane, respectively. Landfill depth was significantly negatively correlated with the relative abundance of MPs size 1-5 mm (p < 0.05) and was positively correlated with the relative abundance of MPs size < 0.2 mm (p < 0.05), suggesting that plastics were broken down during municipal solid waste decomposition. The multiple regression on matrices analysis further showed the landfill depths and plastic morphology significantly impact the MPs distribution. The strains, Lysinibacillus massiliensis (with relative abundance of 1.8%) for low-density polyethylene and polystyrene biodegradation, and Pseudomonas stutzeri (0.1%) for low density polythene and polypropylene biodegradation, were detected on the plastic surface with high relative abundance. Furthermore, 75 plastic degradation species and their associated 31 enzymes (breakdown 24 plastics) were discovered in seven landfills leachate samples.
Topics: Plastics; Microplastics; Polyethylene; China; Water Pollutants, Chemical; Waste Disposal Facilities; Biodegradation, Environmental; Environmental Monitoring
PubMed: 37263024
DOI: 10.1016/j.jhazmat.2023.131676 -
Bioscience, Biotechnology, and... Jul 2023d-Aldotetroses are rare sugars that are obtained via chemical synthesis in low yield. In this study, we demonstrated that d-aldotetroses could be produced using 3...
d-Aldotetroses are rare sugars that are obtained via chemical synthesis in low yield. In this study, we demonstrated that d-aldotetroses could be produced using 3 isomerases. First, l-erythrulose was epimerized using d-tagatose 3-epimerase from Pseudomonas cichorii ST-24. The specific optical rotation of the reaction solution gradually decreased to zero, indicating that approximately 50% of the l-erythrulose was converted to d-erythrulose. d, l-Erythrulose mixture was isomerized with d-arabinose isomerase from Klebsiella pneumoniae 40bXX to produce d-threose, resulting in a conversion rate of 9.35%. d-Erythrose production using l-rhamnose isomerase from Pseudomonas stutzeri LL172 resulted in a conversion rate of 12.9%. Because of the low purity of the purchased d-erythrose, the product was reduced by the Raney nickel catalyst compared with authentic erythritol. We confirmed the products using HPLC and 13C-NMR spectra. This is the first report of d-aldotetrose production using an enzymatic reaction.
Topics: Tetroses; Hexoses; Isomerases; Aldose-Ketose Isomerases; Racemases and Epimerases
PubMed: 37156528
DOI: 10.1093/bbb/zbad058 -
Journal of Hazardous Materials Jul 2023Dissolved organic matter (DOM) play critical roles in arsenic (As) biotransformation in groundwater, but its compositional characteristics and interactions with...
Dissolved organic matter (DOM) play critical roles in arsenic (As) biotransformation in groundwater, but its compositional characteristics and interactions with indigenous microbial communities remain unclear. In this study, DOM signatures coupled with taxonomy and functions of microbial community were characterized in As-enriched groundwater by excitation-emission matrix, Fourier transform ion cyclotron resonance mass spectrometry and metagenomic sequencing. Results showed that As concentrations were significantly positively correlated with DOM humification (r = 0.707, p < 0.01) and the most dominant humic acid-like DOM components (r = 0.789, p < 0.01). Molecular characterization further demonstrated high DOM oxidation degree, with the prevalence of unsaturated oxygen-low aromatics, nitrogen (N/N)-containing compounds and unique CHO molecules in high As groundwater. These DOM properties were consistent with microbial composition and functional potentials. Both taxonomy and binning analyses demonstrated the dominance of Pseudomonas stutzeri, Microbacterium and Sphingobium xenophagum in As-enriched groundwater which possessed abundant As-reducing gene, with organic carbon degrading genes capable of labile to recalcitrant compounds degradation and high potentials of organic nitrogen mineralization to generate ammonium. Besides, most assembled bins in high As groundwater presented strong fermentation potentials which could facilitate carbon utilization by heterotrophic microbes. This study provides better insight into the potential role of DOM mineralization for As release in groundwater system.
Topics: Dissolved Organic Matter; Arsenic; Groundwater; Carbon; Microbiota; Nitrogen
PubMed: 37148792
DOI: 10.1016/j.jhazmat.2023.131566 -
Environmental Research Jul 2023Biodegradation, harnessing the metabolic versatility of microorganisms to reduce agrochemical contaminations, is commonly studied with enriched planktonic cells but...
Biodegradation, harnessing the metabolic versatility of microorganisms to reduce agrochemical contaminations, is commonly studied with enriched planktonic cells but overlooking the dominant lifestyle of microorganisms is to form biofilms, which compromises the efficiency of biodegradation in natural environment. Here, we employed a carbofuran-degrading bacterium Pseudomonas stutzeri PS21 to investigate how the bacterial biofilms formed and responded to agrochemicals. First, the PS21 biofilms formed with a core of bacterial cells enclosing with extracellular polymeric substances (EPSs), and the biofilms were active and resilient when exposed to carbofuran (up to 50 mg L). The formation was regulated by the second messenger bis-(3'-5')-cyclic di-guanosine monophosphate signaling, which strengthened the structural resistance and metabolic basis of biofilms to remain the degrading efficiency as comparable as the planktonic cells. Second, carbofuran distributed heterogeneously in the near-biofilm microenvironment via the covalent adsorption of biofilms, which provided a spontaneous force that enhanced the combination of carbofuran with biofilms to maintain high degrading activity. Additionally, we elucidated the biodegradation was driven by the integrated metabolic system of biofilms involving the extracellular enzymes located in the EPSs. This study exhibited the structural and metabolic advantages of microbial biofilms, highlighting the attractive potentials of exploring biofilm-based strategies to facilitate the in-situ bioremediation of organic contaminations.
Topics: Biodegradation, Environmental; Pseudomonas stutzeri; Carbofuran; Biofilms; Extracellular Polymeric Substance Matrix; Bacteria
PubMed: 37068725
DOI: 10.1016/j.envres.2023.115894 -
Molecular Plant-microbe Interactions :... Sep 2023spp. make up 1.6% of the bacteria in the soil and are found throughout the world. More than 140 species of this genus have been identified, some beneficial to the...
spp. make up 1.6% of the bacteria in the soil and are found throughout the world. More than 140 species of this genus have been identified, some beneficial to the plant. Several species in the family Pseudomonadaceae, including AvOP, A1501, DSM4166, 6HT33bT, and sp. strain K1 can fix nitrogen from the air. The genes required for these reactions are organized in a nitrogen fixation island, obtained via horizontal gene transfer from , , and . Today, this island is conserved in spp. from different geographical locations, which, in turn, have evolved to deal with different geo-climatic conditions. Here, we summarize the molecular mechanisms behind -driven plant growth promotion, with particular focus on improving plant performance at limiting nitrogen (N) and improving plant N content. We describe -plant interaction strategies in the soil, noting that the mechanisms of denitrification, ammonification, and secondary metabolite signaling are only marginally explored. Plant growth promotion is dependent on the abiotic conditions and differs at sufficient and deficient N. The molecular controls behind different plant responses are not fully elucidated. We suggest that superposition of transcriptome, proteome, and metabolome data and their integration with plant phenotype development through time will help fill these gaps. The aim of this review is to summarize the knowledge behind -driven nitrogen fixation and to point to possible agricultural solutions. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
PubMed: 36989040
DOI: 10.1094/MPMI-10-22-0223-CR