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Indian Journal of Ophthalmology Jan 2020We report a rare case of Pseudomonas stutzeri endophthalmitis in an immunocompetent individual along with the review of the literature. A 39-year-old healthy lady... (Review)
Review
We report a rare case of Pseudomonas stutzeri endophthalmitis in an immunocompetent individual along with the review of the literature. A 39-year-old healthy lady presented with sudden painful loss of vision in her right eye. She was diagnosed with postcataract surgery acute endophthalmitis and underwent vitrectomy, intraocular lens explantation and intravitreal antibiotics. P. stutzeri was isolated from vitreous. Though the infection was controlled, the anatomy of the eye could not be salvaged and the right eye became phthisical. P. stutzeri is a rare cause of endophthalmitis with usually poor outcomes.
Topics: Adult; Cataract Extraction; Endophthalmitis; Eye Infections, Bacterial; Female; Humans; Pseudomonas Infections; Pseudomonas stutzeri
PubMed: 31856535
DOI: 10.4103/ijo.IJO_334_19 -
Frontiers in Microbiology 2023Soil salinization and acidification seriously damage soil health and restricts the sustainable development of planting. Excessive application of chemical fertilizer and...
Soil salinization and acidification seriously damage soil health and restricts the sustainable development of planting. Excessive application of chemical fertilizer and other reasons will lead to soil acidification and salinization. This study focus on acid and salinized soil, investigated the effect of phosphate-solubilizing bacteria, MJ1 combined with nitrogen-fixing bacteria DSM4166 or mutant CHA0- on crop quality, soil physicochemical properties, and microbial communities. A total of 5 treatments were set: regular fertilization (T1), regular fertilization with MJ1 and DSM4166 (T2), regular fertilization with MJ1 and CHA0- (T3), 30%-reducing fertilization with MJ1 and DSM4166 (T4), and 30%-reducing fertilization with MJ1 and CHA0- (T5). It was found that the soil properties (OM, HN, TN, AP, AK, and SS) and crop quality of cucumber (yield production, protein, and vitamin C) and lettuce (yield production, vitamin C, nitrate, soluble protein, and crude fiber) showed a significant response to the inoculated strains. The combination of MJ1 with DSM4166 or CHA0- influenced the diversity and richness of bacterial community in the lettuce-grown soil. The organismal system-, cellular process-, and metabolism-correlated bacteria and saprophytic fungi were enriched, which were speculated to mediate the response to inoculated strains. pH, OM, HN, and TN were identified to be the major factors correlated with the soil microbial community. The inoculation of MJ1 with DSM4166 and CHA0- could meet the requirement of lettuce and cucumber growth after reducing fertilization in acid and salinized soil, which provides a novel candidate for the eco-friendly technique to meet the carbon-neutral topic.
PubMed: 36819023
DOI: 10.3389/fmicb.2023.1064358 -
Synthetic and Systems Biotechnology Jun 2023The biological treatment of wastewater with high concentrations of ammonia nitrogen has become a hot research issue, but there are limited reports on the mechanism of...
The biological treatment of wastewater with high concentrations of ammonia nitrogen has become a hot research issue, but there are limited reports on the mechanism of ammonia nitrogen utilization by microorganisms. In this paper, a transcriptomic approach was used to investigate the differences in gene expression at 500.0 mg/L (Amo 500) and 100.0 mg/L (Amo 100) ammonium concentrations to reveal the mechanism of ammonia nitrogen removal from water by F2. The transcriptome data showed 1015 (459 up-regulated and 556 down-regulated) differentially expressed genes with functional gene annotation related to nitrogen source metabolism, glycolysis, tricarboxylic acid cycle, extracellular polysaccharide synthesis, energy conversion and transmembrane transport, revealing the metabolic process of ammonium nitrogen conversion to biological nitrogen in F2 through assimilation. To verify the effect of ammonium transporter protein (AmtB) of cell membrane on assimilation, a F2-Δ mutant strain was obtained by constructing a knockout plasmid (pK18mobsacB-Δ), and it was found that the growth characteristics and ammonium removal rate of the mutant strain were significantly reduced at high ammonium concentration. The carbon source components and dissolved oxygen conditions were optimized after analyzing the transcriptome data, and the ammonium removal rate was increased from 41.23% to 94.92% with 500.0 mg/L ammonium concentration. The study of F2 transcript level reveals the mechanism of ammonia nitrogen influence on microbial assimilation process and improvement strategy, which provides a new strategy for the treatment of ammonia nitrogen wastewater.
PubMed: 37033292
DOI: 10.1016/j.synbio.2023.03.002 -
Applied and Environmental Microbiology Aug 2023Several microbial taxa have been associated with food processing facilities, and they might resist by attaching on tools and equipment even after sanitation procedures,...
Several microbial taxa have been associated with food processing facilities, and they might resist by attaching on tools and equipment even after sanitation procedures, producing biofilms that adhere to the surfaces and might embed other microorganisms, including spoilers and pathogens. There is increasing evidence that these communities can be transferred to the final product. To explore the microbial contamination routes in a facility producing ice creams, we collected foods and environmental swabs from industrial surfaces of equipment and tools and performed taxonomic and functional analyses of the microbial DNA extracted from the environmental samples. Our results suggest that complex communities dominated by psychrotrophic bacteria (e.g., Pseudomonas and Acinetobacter spp.) inhabit the food processing environment, and we demonstrate that these communities might be transferred from the surfaces to the products. Functional analysis performed on environmental samples highlighted the presence of several genes linked to antimicrobial resistance and adherence on abiotic surfaces; such genes were more abundant on food contact (FC) than on other surfaces. Metagenome-assembled genomes (MAGs) of Pseudomonas stutzeri showed genes linked with biofilm formation and motility, which are surely linked to colonizing capabilities in the processing lines. The study highlights clear potential advantages of applying microbiome mapping in the food industry for source tracking of microbial contamination and for planning appropriate sanitization strategies. Several microbial species might permanently establish in food processing facilities, thus contributing to food loss. In fact, food contact surfaces might transfer microorganisms to intermediates and products, potentially representing a hazard to human health. In this work, we provide evidence of the existence of complex microbial communities overcoming sanitation in an ice cream-producing facility. These communities harbored several genes that could potentially lead to attachment to surfaces and antimicrobial resistance. Also, prediction of routes of contamination showed that several potential spoilage taxa might end up in the final product. Importantly, in this work, we show that mapping the environmental microbiome is a high-resolution technique that might help food business operators ensure food quality and safety through detection of potentially hazardous microorganisms.
Topics: Humans; Ice Cream; Virulence; Bacteria; Food Handling; Biofilms; Anti-Infective Agents; Food Microbiology
PubMed: 37432121
DOI: 10.1128/aem.00765-23 -
Scientific Reports Feb 2020Biological ammonium removal via heterotrophic nitrification/aerobic denitrification (HN/AD) presents several advantages in relation to conventional removal processes,...
Physicochemical characterization of Pseudomonas stutzeri UFV5 and analysis of its transcriptome under heterotrophic nitrification/aerobic denitrification pathway induction condition.
Biological ammonium removal via heterotrophic nitrification/aerobic denitrification (HN/AD) presents several advantages in relation to conventional removal processes, but little is known about the microorganisms and metabolic pathways involved in this process. In this study, Pseudomonas stutzeri UFV5 was isolated from an activated sludge sample from oil wastewater treatment station and its ammonium removal via HN/AD was investigated by physicochemical and molecular approaches to better understand this process and optimize the biological ammonium removal in wastewater treatment plants. Results showed that P. stutzeri UFV5 removed all the ammonium in 48-72 hours using pyruvate, acetate, citrate or sodium succinate as carbon sources, C/N ratios 6, 8, 10 and 12, 3-6% salinities, pH 7-9 and temperatures of 20-40 °C. Comparative genomics and PCR revealed that genes encoding the enzymes involved in anaerobic denitrification process are present in P. stutzeri genome, but no gene that encodes enzymes involved in autotrophic nitrification was found. Furthermore, transcriptomics showed that none of the known enzymes of autotrophic nitrification and anaerobic denitrification had their expression differentiated and an upregulation of the biosynthesis machinery and protein translation was observed, besides several genes with unknown function, indicating a non-conventional mechanism involved in HN/AD process.
Topics: Aerobiosis; Ammonium Compounds; Bacterial Proteins; Biodegradation, Environmental; Denitrification; Gene Expression Regulation, Bacterial; Heterotrophic Processes; Nitrification; Pseudomonas stutzeri; Sewage; Transcriptome; Wastewater
PubMed: 32042029
DOI: 10.1038/s41598-020-59279-7 -
Frontiers in Bioengineering and... 2023Acetate is a low-cost feedstock for the production of different bio-chemicals. Electrochemical reduction of CO into acetate and subsequent acetate fermentation is a...
Acetate is a low-cost feedstock for the production of different bio-chemicals. Electrochemical reduction of CO into acetate and subsequent acetate fermentation is a promising method for transforming CO into value-added chemicals. However, the significant inhibitory effect of acetate on microbial growth remains a barrier for acetate-based biorefinery. In this study, the deletion of genes involved in L-leucine degradation was found to be beneficial for the growth of A1501 in acetate. (Δ), in which the hydroxymethylglutaryl-CoA lyase catalyzing -hydroxy--methylglutaryl-CoA into acetyl-CoA and acetoacetate was deleted, grew faster than other mutants and exhibited increased tolerance to acetate. Then, the genes from H16 for poly-3-hydroxybutyrate (PHB) biosynthesis were overexpressed in (∆) and the recombinant strain (∆-) can accumulate 0.11 g L PHB from commercial acetate. Importantly, (∆-) can also use CO-derived acetate to produce PHB and the accumulated PHB accounted for 5.42% (w/w) of dried cell weight of (∆-).
PubMed: 38026858
DOI: 10.3389/fbioe.2023.1297431 -
Frontiers in Medicine 2023Although pre/pro/postbiotics have become more prevalent in dermatologic and cosmetic fields, the mode of action when topically applied is largely unknown. A multi-omic...
INTRODUCTION
Although pre/pro/postbiotics have become more prevalent in dermatologic and cosmetic fields, the mode of action when topically applied is largely unknown. A multi-omic approach was applied to decipher the impact of the skincare products with pre/postbiotics on skin microbiome and metabolome.
METHODS
Subjects with dry skin applied a body wash and body lotion with or without pre/postbiotics for 6 weeks. Skin hydration was measured at baseline, 3 and 6 weeks. Skin swabs were collected for 16S rRNA gene sequencing, metagenomics and metabolomics analysis.
RESULTS
Skin hydration significantly increased in both groups. The prebiotic group significantly reduced opportunistic pathogens, e.g., and , and increased the commensals, e.g., , . Bacterial sugar degradation pathways were enriched in the prebiotic group, while fatty acid biosynthesis pathways were reduced in control. The changes on skin metabolome profiles by the products were more prominent. The prebiotic group performed greater modulation on many clinically-relevant metabolites compared to control. Correlation analysis showed and positively correlated with skin hydration, and negatively correlated with the metabolites that are positively associated with skin hydration improvement.
CONCLUSION
This holistic study supported a hypothesis that the pre/postbiotics increased skin hydration through the modulation of skin microbiome, metabolic pathways and metabolome.
PubMed: 37534320
DOI: 10.3389/fmed.2023.1165980 -
MicrobiologyOpen Apr 2020Heterologous production of extracellular polyhydroxybutyrate (PHB) depolymerases (PhaZs) has been of interest for over 30 years, but implementation is sometimes...
Heterologous production of extracellular polyhydroxybutyrate (PHB) depolymerases (PhaZs) has been of interest for over 30 years, but implementation is sometimes difficult and can limit the scope of research. With the constant development of tools to improve recombinant protein production in Escherichia coli, we propose a method that takes characteristics of PhaZs from different bacterial strains into account. Recombinant His-tagged versions of PhaZs (rPhaZ) from Comamonas testosteroni 31A, Cupriavidus sp. T1, Marinobacter algicola DG893, Pseudomonas stutzeri, and Ralstonia sp. were successfully produced with varying expression, solubility, and purity levels. PhaZs from C. testosteroni and P. stutzeri were more amenable to heterologous expression in all aspects; however, using the E. coli Rosetta-gami B(DE3) expression strain and establishing optimal conditions for expression and purification (variation of IPTG concentration and use of size exclusion columns) helped circumvent low expression and purity for the other PhaZs. Degradation activity of the rPhaZs was compared using a simple PHB plate-based method, adapted to test for various pH and temperatures. rPhaZ from M. algicola presented the highest activity at 15°C, and rPhaZs from Cupriavidus sp. T1 and Ralstonia sp. had the highest activity at pH 5.4. The methods proposed herein can be used to test the production of soluble recombinant PhaZs and to perform preliminary evaluation for applications that require PHB degradation.
Topics: Bacteria; Bioreactors; Carboxylic Ester Hydrolases; Comamonas testosteroni; Cupriavidus; Escherichia coli; Marinobacter; Pseudomonas stutzeri; Ralstonia; Recombinant Proteins
PubMed: 32087608
DOI: 10.1002/mbo3.1001 -
Microorganisms Nov 2021Integrative and conjugative elements (ICEs) are chromosomally integrated self-transmissible mobile genetic elements. Although some ICEs are known to carry genes for the...
A New ICE Subfamily Integrative and Conjugative Element Responsible for Horizontal Transfer of Biphenyl and Salicylic Acid Catabolic Pathway in the PCB-Degrading Strain KF716.
Integrative and conjugative elements (ICEs) are chromosomally integrated self-transmissible mobile genetic elements. Although some ICEs are known to carry genes for the degradation of aromatic compounds, information on their genetic features is limited. We identified a new member of the ICE family carrying biphenyl catabolic genes and salicylic acid catabolic genes from the PCB-degrading strain KF716. The 117-kb ICEKF716 contains common core regions exhibiting homology with those of degradative ICE from B13 and ICE from sp. CIB. A comparison of the gene loci collected from the public database revealed that several putative ICEs from B6-2 JAB1, AN10 and 2A20 had highly conserved core regions with those of ICEKF716, along with the variable region that encodes the catabolic genes for biphenyl, naphthalene, toluene, or phenol. These data indicate that this type of ICE subfamily is ubiquitously distributed within aromatic compound-degrading bacteria. ICEKF716 was transferred from KF716 to PAO1 via a circular extrachromosomal intermediate form. In this study, we describe the structure and genetic features of ICEKF716 compared to other catabolic ICEs.
PubMed: 34946064
DOI: 10.3390/microorganisms9122462 -
Applied and Environmental Microbiology Apr 2022Aerobic methanotrophic activity is highly dependent on copper availability, and methanotrophs have developed multiple strategies to collect copper. Specifically, when...
Aerobic methanotrophic activity is highly dependent on copper availability, and methanotrophs have developed multiple strategies to collect copper. Specifically, when copper is limiting (ambient concentrations less than 1 μM), some methanotrophs produce and secret a small modified peptide (less than 1,300 Da) termed methanobactin (MB) that binds copper with high affinity. As MB is secreted into the environment, other microbes that require copper for their metabolism may be inhibited as MB may make copper unavailable; e.g., inhibition of denitrifiers as complete conversion nitrate to dinitrogen involves multiple enzymes, some of which are copper-dependent. Of key concern is inhibition of the copper-dependent nitrous oxide reductase (NosZ), the only known enzyme capable of converting nitrous oxide (NO) to dinitrogen. Herein, we show that different forms of MB differentially affect copper uptake and NO reduction by Pseudomonas stutzeri strain DCP-Ps1 (that expresses clade I NosZ) and Dechloromonas aromatica strain RCB (that expresses clade II NosZ). Specifically, in the presence of MB from Methylocystis sp. strain SB2 (SB2-MB), copper uptake and expression were more significantly reduced than in the presence of MB from Methylosinus trichosporium OB3b (OB3b-MB). Further, NO accumulation increased more significantly for both P. stutzeri strain DCP-Ps1 and D. aromatica strain RCB in the presence of SB2-MB versus OB3b-MB. These data illustrate that copper competition between methanotrophs and denitrifying bacteria can be significant and that the extent of such competition is dependent on the form of MB that methanotrophs produce. Herein, it was demonstrated that the different forms of methanobactin differentially enhance NO emissions from Pseudomonas stutzeri strain DCP-Ps1 (harboring clade I nitrous oxide reductase) and Dechloromonas aromatica strain RCB (harboring clade II nitrous oxide reductase). This work contributes to our understanding of how aerobic methanotrophs compete with denitrifiers for the copper uptake and also suggests how MBs prevent copper collection by denitrifiers, thus downregulating expression of nitrous oxide reductase. This study provides critical information for enhanced understanding of microbe-microbe interactions that are important for the development of better predictive models of net greenhouse gas emissions (i.e., methane and nitrous oxide) that are significantly controlled by microbial activity.
Topics: Betaproteobacteria; Copper; Imidazoles; Methylocystaceae; Methylosinus trichosporium; Nitrous Oxide; Oligopeptides; Pseudomonas stutzeri
PubMed: 35285718
DOI: 10.1128/aem.02346-21