scholarly journals Diclofenac Degradation—Enzymes, Genetic Background and Cellular Alterations Triggered in Diclofenac-Metabolizing Strain Pseudomonas moorei KB4

2020 ◽  
Vol 21 (18) ◽  
pp. 6786
Author(s):  
Joanna Żur ◽  
Artur Piński ◽  
Danuta Wojcieszyńska ◽  
Wojciech Smułek ◽  
Urszula Guzik
Keyword(s):  
Chemical Oxidation ◽  
Simultaneous Increase ◽  
Bacterial Cells ◽  
Environmental Matrices ◽  
Alkaline Phosphatases ◽  
Biotransformation Enzymes ◽  
Genes Encoding ◽  
Metabolic Conditions ◽  
Elevated Activity ◽  
Multi Level

Diclofenac (DCF) constitutes one of the most significant ecopollutants detected in various environmental matrices. Biological clean-up technologies that rely on xenobiotics-degrading microorganisms are considered as a valuable alternative for chemical oxidation methods. Up to now, the knowledge about DCF multi-level influence on bacterial cells is fragmentary. In this study, we evaluate the degradation potential and impact of DCF on Pseudomonas moorei KB4 strain. In mono-substrate culture KB4 metabolized 0.5 mg L−1 of DCF, but supplementation with glucose (Glc) and sodium acetate (SA) increased degraded doses up to 1 mg L−1 within 12 days. For all established conditions, 4′-OH-DCF and DCF-lactam were identified. Gene expression analysis revealed the up-regulation of selected genes encoding biotransformation enzymes in the presence of DCF, in both mono-substrate and co-metabolic conditions. The multifactorial analysis of KB4 cell exposure to DCF showed a decrease in the zeta-potential with a simultaneous increase in the cell wall hydrophobicity. Magnified membrane permeability was coupled with the significant increase in the branched (19:0 anteiso) and cyclopropane (17:0 cyclo) fatty acid accompanied with reduced amounts of unsaturated ones. DCF injures the cells which is expressed by raised activities of acid and alkaline phosphatases as well as formation of lipids peroxidation products (LPX). The elevated activity of superoxide dismutase (SOD) and catalase (CAT) testified that DCF induced oxidative stress.

scholarly journals Diversity of Free-Living and Attached Bacteria in Offshore Western Mediterranean Waters as Depicted by Analysis of Genes Encoding 16S rRNA

1999 ◽  
Vol 65 (2) ◽  
pp. 514-522 ◽  
Author(s):  
Silvia G. Acinas ◽  
Josefa Antón ◽  
Francisco Rodríguez-Valera
Keyword(s):  
16S Rdna ◽  
Restriction Analysis ◽  
Western Mediterranean ◽  
Bacterial Cells ◽  
Free Living ◽  
Attached Bacteria ◽  
Genes Encoding ◽  
Community Fingerprinting ◽  
Close Relatives ◽  
Alteromonas Macleodii

ABSTRACT In a previous study (S. G. Acinas, F. Rodrı́guez-Valera, and C. Pedrós-Alió, FEMS Microbiol. Ecol. 24:27–40, 1997), community fingerprinting by 16S rDNA restriction analysis applied to Mediterranean offshore waters showed that the free-living pelagic bacterial community was very different from the bacterial cells aggregated or attached to particles of more than about 8 μm. Here we have studied both assemblages at three depths (5, 50, and 400 m) by cloning and sequencing the 16S rDNA obtained from the same samples, and we have also studied the samples by scanning electron microscopy to detect morphology patterns. As expected, the sequences retrieved from the assemblages were very different. The subsample of attached bacteria contained very little diversity, with close relatives of a well-known species of marine bacteria, Alteromonas macleodii, representing the vast majority of the clones at every depth. On the other hand, the free-living assemblage was highly diverse and varied with depth. At 400 m, close relatives of cultivated γProteobacteria predominated, but as shown by other authors, near the surface most clones were related to phylotypes described only by sequence, in which the α Proteobacteria of the SAR11 cluster predominated. The new technique of rDNA internal spacer analysis has been utilized, confirming these results. Clones representative of the A. macleodii cluster have been completely sequenced, producing a picture that fits well with the idea that they could represent a genus with at least two species and with a characteristic depth distribution.

scholarly journals On the Ability of Perfluorohexane Sulfonate (PFHxS) Bioaccumulation by Two Pseudomonas sp. Strains Isolated from PFAS-Contaminated Environmental Matrices

2020 ◽  
Vol 8 (1) ◽  
pp. 92 ◽  
Author(s):  
Alessandro Presentato ◽  
Silvia Lampis ◽  
Andrea Vantini ◽  
Flavio Manea ◽  
Francesca Daprà ◽  
...  
Keyword(s):  
Short Chain ◽  
Industrial Processes ◽  
Bacterial Cells ◽  
Pseudomonas Sp ◽  
Environmental Matrices ◽  
Synthetic Compounds ◽  
Physiological Conditions ◽  
End Products ◽  
Polyfluoroalkyl Substances ◽  
Thermal And Chemical Stability

PFASs (perfluoroalkyl and polyfluoroalkyl substances) are highly fluorinated, aliphatic, synthetic compounds with high thermal and chemical stability as well as unique amphiphilic properties which make them ingredients in a range of industrial processes. PFASs have attracted consideration due to their persistence, toxicity and bioaccumulation tendency in the environment. Recently, attention has begun to be addressed to shorter-chain PFASs, such as perfluorohexane sulfonate [PFHxS], apparently less toxic to and more easily eliminated from lab animals. However, short-chain PFASs represent end-products from the transformation of fluorotelomers whose biotic breakdown reactions have not been identified to date. This means that such emergent pollutants will tend to accumulate and persist in ecosystems. Since we are just learning about the interaction between short-chain PFASs and microorganisms, this study reports on the response to PFHxS of two Pseudomonas sp. strains isolated from environmental matrices contaminated by PFASs. The PFHxS bioaccumulation potential of these strains was unveiled by exploiting different physiological conditions as either axenic or mixed cultures under alkanothrofic settings. Moreover, electron microscopy revealed nonorthodox features of the bacterial cells, as a consequence of the stress caused by both organic solvents and PFHxS in the culturing substrate.

scholarly journals Potential Use of Silica Nanoparticles for the Microbial Stabilisation of Wine: An In Vitro Study Using Oenococcus oeni as a Model

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1338
Author(s):  
Kamila Pachnowska ◽  
Krzysztof Cendrowski ◽  
Xymena Stachurska ◽  
Paweł Nawrotek ◽  
Adrian Augustyniak ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Oenococcus Oeni ◽  
Chemical Oxidation ◽  
Alternative Methods ◽  
Bacterial Cells ◽  
Silica Nanospheres ◽  
Cell Counts ◽  
Transmission Electron ◽  
Phosphate Buffered Saline

The emerging trend towards the reduction of SO2 in winemaking has created a need to look for alternative methods to ensure the protection of wine against the growth of undesired species of microorganisms and to safely remove wine microorganisms. This study describes the possible application of silica nanospheres as a wine stabilisation agent, with Oenococcus oeni (DSM7008) as a model strain. The experiment was conducted firstly on model solutions of phosphate-buffered saline and 1% glucose. Their neutralising effect was tested under stirring with the addition of SiO2 (0.1, 0.25, and 0.5 mg/mL). Overall, the highest concentration of nanospheres under continuous stirring resulted in the greatest decrease in cell counts. Transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses showed extensive damage to the bacterial cells after stirring with silica nanomaterials. Then, the neutralising effect of 0.5 mg/mL SiO2 was tested in young red wine under stirring, where cell counts were reduced by over 50%. The obtained results suggest that silica nanospheres can serve as an alternative way to reduce or substitute the use of sulphur dioxide in the microbial stabilisation of wine. In addition, further aspects of following investigations should focus on the protection against enzymatic and chemical oxidation of wine.

scholarly journals Fast and reliable procedure developed to generate soft rot Pectobacteriaceae (Pectobacterium spp. and Dickeya spp.) Tn5 mutants resistant to bacteriophage infection

2020 ◽  
Vol 159 (1) ◽  
pp. 227-231
Author(s):  
Robert Czajkowski
Keyword(s):  
Growth Medium ◽  
Aminolevulinic Acid ◽  
Soft Rot ◽  
Lytic Bacteriophage ◽  
Bacterial Cells ◽  
Bacteriophage Infection ◽  
Genes Encoding ◽  
Tn5 Mutants ◽  
Bacterial Mutants ◽  
Fast Procedure

AbstractA simple and fast procedure has been developed to generate soft rot Pectobacteriaceae (SRP: Pectobacterium spp. and Dickeya spp.) Tn5 mutants in genes encoding receptors used by bacteriophages to interact with their hosts, for the follow-up studies. The procedure is inexpensive and does not require any specialized tools and/or dedicated technical support. The neomycin-resistant SRP Tn5 mutants are generated via conjugation with a transposon donor Escherichia coli ST18 strain (requiring 5-aminolevulinic acid (5-ALA) to survive) carrying pFAJ1819-mini-Tn5-neoR. The conjugation is done on solid medium supplemented with 5-ALA. After conjugation bacterial cells are collected, suspended in liquid bacterial medium, added to the suspension containing lytic bacteriophages and incubated for the additional 30 min with shaking (120 rpm). During this stage, the transposon recipients (Pectobacterium spp. and/or Dickeya spp. Tn5 mutants), susceptible to bacteriophage infection are lysed. Likewise, due to the lack of 5-ALA in the growth medium, E. coli ST18 (transposon donor) cells die at this stage. Finally, after incubation, the bacterial mutants with the Tn5 insertions, resistant to phage infection are selected on solid growth medium supplemented with neomycin. The Tn5 insertion sites are sequenced to acquire knowledge about the Tn5-distrupted genes and their putative function in phage-host interactions. The proposed assay allows generation of a number of immediately-available Tn5 mutants expressing phage-resistant phenotypes in a short time (ca. 48 h) that can be later characterized for various other phenotypic features. In this study, as a proof-of-concept, this method has been used to generate Dickeya solani IPO2222 Tn5 mutants resistant to infection caused by the lytic bacteriophage ɸD5.

scholarly journals Coordinated Zinc Homeostasis Is Essential for the Wild-Type Virulence of Brucella abortus

2015 ◽  
Vol 197 (9) ◽  
pp. 1582-1591 ◽  
Author(s):  
Lauren M. Sheehan ◽  
James A. Budnick ◽  
R. Martin Roop ◽  
Clayton C. Caswell
Keyword(s):  
Mouse Model ◽  
Brucella Abortus ◽  
Zinc Uptake ◽  
Zinc Homeostasis ◽  
Zinc Toxicity ◽  
Uptake System ◽  
Bacterial Cells ◽  
Gene Encoding ◽  
Content Type ◽  
Genes Encoding

ABSTRACTMetal homeostasis in bacterial cells is a highly regulated process requiring intricately coordinated import and export, as well as precise sensing of intracellular metal concentrations. The uptake of zinc (Zn) has been linked to the virulence ofBrucella abortus; however, the capacity ofBrucellastrains to sense Zn levels and subsequently coordinate Zn homeostasis has not been described. Here, we show that expression of the genes encoding the zinc uptake system ZnuABC is negatively regulated by the Zn-sensing Fur family transcriptional regulator, Zur, by direct interactions between Zur and the promoter region ofznuABC. Moreover, the MerR-type regulator, ZntR, controls the expression of the gene encoding the Zn exporter ZntA by binding directly to its promoter. Deletion ofzurorzntRalone did not result in increased zinc toxicity in the corresponding mutants; however, deletion ofzntAled to increased sensitivity to Zn but not to other metals, such as Cu and Ni, suggesting that ZntA is a Zn-specific exporter. Strikingly, deletion ofzntRresulted in significant attenuation ofB. abortusin a mouse model of chronic infection, and subsequent experiments revealed that overexpression ofzntAin thezntRmutant is the molecular basis for its decreased virulence.IMPORTANCEThe importance of zinc uptake forBrucellapathogenesis has been demonstrated previously, but to date, there has been no description of how overall zinc homeostasis is maintained and genetically controlled in the brucellae. The present work defines the predominant zinc export system, as well as the key genetic regulators of both zinc uptake and export inBrucella abortus. Moreover, the data show the importance of precise coordination of the zinc homeostasis systems as disregulation of some elements of these systems leads to the attenuation ofBrucellavirulence in a mouse model. Overall, this study advances our understanding of the essential role of zinc in the pathogenesis of intracellular bacteria.

scholarly journals Identification and Characterization of Genes Encoding a Putative ABC-Type Transporter Essential for Utilization of γ-Hexachlorocyclohexane in Sphingobium japonicum UT26

2007 ◽  
Vol 189 (10) ◽  
pp. 3712-3720 ◽  
Author(s):  
Ryo Endo ◽  
Yoshiyuki Ohtsubo ◽  
Masataka Tsuda ◽  
Yuji Nagata
Keyword(s):  
Abc Transporter ◽  
Sole Source ◽  
Bacterial Cells ◽  
New Genes ◽  
Hydrophobic Compounds ◽  
Dead End ◽  
Genes Encoding ◽  
Degradation Activity ◽  
Mutant Cells

ABSTRACT Sphingobium japonicum UT26 utilizes γ-hexachlorocyclohexane (γ-HCH) as its sole source of carbon and energy. In our previous studies, we cloned and characterized genes encoding enzymes for the conversion of γ-HCH to β-ketoadipate in UT26. In this study, we analyzed a mutant obtained by transposon mutagenesis and identified and characterized new genes encoding a putative ABC-type transporter essential for the utilization of γ-HCH in strain UT26. This putative ABC transporter consists of four components, permease, ATPase, periplasmic protein, and lipoprotein, encoded by linK, linL, linM, and linN, respectively. Mutation and complementation analyses indicated that all the linKLMN genes are required, probably as a set, for γ-HCH utilization in UT26. Furthermore, the mutant cells deficient in this putative ABC transporter showed (i) higher γ-HCH degradation activity and greater accumulation of the toxic dead-end product 2,5-dichlorophenol (2,5-DCP), (ii) higher sensitivity to 2,5-DCP itself, and (iii) higher permeability of hydrophobic compounds than the wild-type cells. These results strongly suggested that LinKLMN are involved in γ-HCH utilization by controlling membrane hydrophobicity. This study clearly demonstrated that a cellular factor besides catabolic enzymes and transcriptional regulators is essential for utilization of xenobiotic compounds in bacterial cells.

scholarly journals Economy of Operon Formation: Cotranscription Minimizes Shortfall in Protein Complexes

mBio ◽  
2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Kim Sneppen ◽  
Steen Pedersen ◽  
Sandeep Krishna ◽  
Ian Dodd ◽  
Szabolcs Semsey
Keyword(s):  
Protein Complexes ◽  
Small Cells ◽  
Eukaryotic Cells ◽  
Bacterial Cells ◽  
Economic Gain ◽  
Eukaryotic Genes ◽  
Genes Encoding ◽  
Encoding Protein

ABSTRACT Genes of prokaryotes and Archaea are often organized in cotranscribed groups, or operons. In contrast, eukaryotic genes are generally transcribed independently. Here we show that there is a substantial economic gain for the cell to cotranscribe genes encoding protein complexes because it synchronizes the fluctuations, or noise, in the levels of the different components. This correlation substantially reduces the shortfall in production of the complex. This benefit is relatively large in small cells such as bacterial cells, in which there are few mRNAs and proteins per cell, and is diminished in larger cells such as eukaryotic cells.

scholarly journals Transcriptional Responses of Uropathogenic Escherichia coli to Increased Environmental Osmolality Caused by Salt or Urea

2012 ◽  
Vol 81 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Benjamin Withman ◽  
Thusitha S. Gunasekera ◽  
Pavani Beesetty ◽  
Richard Agans ◽  
Oleg Paliy
Keyword(s):  
Escherichia Coli ◽  
Inorganic Ions ◽  
Bacterial Cells ◽  
Adaptive Responses ◽  
Transcriptional Responses ◽  
Upec Strain ◽  
Content Type ◽  
Urinary Infections ◽  
Genes Encoding ◽  
Tract Infections

UropathogenicEscherichia coli(UPEC) is the most common causative agent of urinary tract infections in humans. The majority of urinary infections develop via ascending route through the urethra, where bacterial cells come in contact with human urine prior to reaching the bladder or kidneys. Since urine contains significant amounts of inorganic ions and urea, it imposes osmotic and denaturing stresses on bacterial cells. In this study, we determined the transcriptional adaptive responses of UPEC strain CFT073 to the presence of 0.3 M NaCl or 0.6 M urea in the growth medium. The cell responses to these two osmolytes were drastically different. Although most of the genes of the osmotically inducible regulon were overexpressed in medium with salt, urea failed to stimulate osmotic stress response. At the same time, UPEC colonization genes encoding type 1 and F1C fimbriae and capsule biosynthesis were transcriptionally induced in the presence of urea but did not respond to increased salt concentration. We speculate that urea can potentially be sensed by uropathogenic bacteria to initiate infection program. In addition, several molecular chaperone genes were overexpressed in the presence of urea, whereas adding NaCl to the medium led to an upregulation of a number of anaerobic metabolism pathways.

Adhesins encoded by the gingipain genes of Porphyromonas gingivalis are responsible for co-aggregation with Prevotella intermedia

Microbiology ◽  
2003 ◽  
Vol 149 (5) ◽  
pp. 1257-1264 ◽  
Author(s):  
Arihide Kamaguchi ◽  
Tohru Ohyama ◽  
Eiko Sakai ◽  
Reiko Nakamura ◽  
Toshihiro Watanabe ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Bacterial Species ◽  
Gel Filtration ◽  
Prevotella Intermedia ◽  
Bacterial Cells ◽  
Terminal Portion ◽  
Genes Encoding ◽  
Sepharose 4B ◽  
Genomic Dna Sequence ◽  
Aggregation Factors

Co-aggregation among bacterial cells caused by the adherence of one bacterial species to another is a potential colonization mechanism. Several putative aggregation factors for co-aggregation between Porphyromonas (Por.) gingivalis and Prevotella (Pre.) intermedia were partially purified from Por. gingivalis vesicles by gel filtration and affinity chromatography. Antisera against the aggregation factors were made. Analysis using these antisera revealed that 18 and 44 kDa proteins might be responsible for Por. gingivalis vesicle-mediated aggregation of Pre. intermedia. Using antiserum against the 18 kDa protein, the DNA region encoding it was cloned from Por. gingivalis genomic DNA. Sequence analysis revealed that the DNA region was located within the rgpA and kgp genes, encoding Arg-gingipain (Rgp) and Lys-gingipain (Kgp), respectively, and it encoded non-catalytic adhesin domain regions, namely a C-terminal portion of HGP15, the entire HGP17 sequence and an N-terminal portion of HGP27. A portion of the DNA sequence was also found in the haemagglutinin A (hagA) gene. A recombinant glutathione S-transferase (GST)–HGP17 fusion protein reacted to antiserum against the 18 kDa protein and Pre. intermedia cells could adhere to GST–HGP17-conjugated Sepharose 4B beads, indicating that the HGP17 domain protein is responsible for Por. gingivalis vesicle-mediated aggregation of Pre. intermedia.

scholarly journals Identification of Klebsiella Variicola T29A Genes Involved In Tolerance To Desiccation

2019 ◽  
Vol 13 (1) ◽  
pp. 256-267 ◽  
Author(s):  
Osvaldo Rodríguez-Andrade ◽  
Andrés Corral-Lugo ◽  
Yolanda E. Morales-García ◽  
Verónica Quintero-Hernández ◽  
América P. Rivera-Urbalejo ◽  
...  
Keyword(s):  
Bacterial Strain ◽  
Abiotic Factors ◽  
Random Mutagenesis ◽  
Protein Domain ◽  
Bacterial Cells ◽  
Bacterial Survival ◽  
Tn5 Transposon ◽  
Genes Encoding ◽  
Type Gene ◽  
Corn Plants

Introduction: Several plant-beneficial bacteria have the capability to promote the growth of plants through different mechanisms. The survival of such bacteria could be affected by environmental abiotic factors compromising their capabilities of phytostimulation. One of the limiting abiotic factors is low water availability. Materials and Methods: In extreme cases, bacterial cells can suffer desiccation, which triggers harmful effects on cells. Bacteria tolerant to desiccation have developed different strategies to cope with these conditions; however, the genes involved in these processes have not been sufficiently explored. Klebsiella variicola T29A is a beneficial bacterial strain that promotes the growth of corn plants and is highly tolerant to desiccation. In the present work, we investigated genes involved in desiccation tolerance. Results & Discussion: As a result, a library of 8974 mutants of this bacterial strain was generated by random mutagenesis with mini-Tn5 transposon, and mutants that lost the capability to tolerate desiccation were selected. We found 14 sensitive mutants; those with the lowest bacterial survival rate contained mini-Tn5 transposon inserted into genes encoding a protein domain related to BetR, putative secretion ATPase and dihydroorotase. The mutant in the betR gene had the lowest survival; therefore, the mutagenized gene was validated using specific amplification and sequencing. Conclusion: Trans complementation with the wild-type gene improved the survival of the mutant under desiccation conditions, showing that this gene is a determinant for the survival of K. variicola T29A under desiccation conditions.

Sign in / Sign up

Export Citation Format

Share Document