scholarly journals Surfactants Efficiency on Pentachlophenol Contaminated Wastewater Enhanced by Pseudomonas Putida AJ 785569

2021 ◽  
Author(s):  
rim werheni Ammeri ◽  
yassin hidri ◽  
WAFA HASSRN ◽  
ines mehri ◽  
Nesrine khelifi ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Tween 80 ◽  
Bacterial Cells ◽  
A Value ◽  
Biofilm Development

Abstract This study has objectives to assess the effects of some surfactants on (1) the bacterial growth, (2) PCP (800 mgL -1 ) rate removal, and at last (3) biofilm development. Three different surfactants are used in this case as anionic (SDS), no anionic Tween 80 (TW80) and cationic (CTAB). The results improve that there was an adsorption of PCP by the bacterial cells of around 30 mg . L -1 and PCP removal of around 720 mgL -1 after seven days. It appeared that the surfactant adding affected the bacterial growth and reach a maximum of PCP removal with SDS addition with a value 676.66 mg L -1 in S.WW then CTAB and TW80. Biofilm formation in BHI with PCP showed a clear acceleration and enhancement of this activity with SDS addition. Besides, biofilm morphotype of selected strain appeared affected in form, density, and colour after different situations of stress caused by various surfactants or PCP.

scholarly journals Electrical spiking in bacterial biofilms

2015 ◽  
Vol 12 (102) ◽  
pp. 20141036 ◽  
Author(s):  
Elisa Masi ◽  
Marzena Ciszak ◽  
Luisa Santopolo ◽  
Arcangela Frascella ◽  
Luciana Giovannetti ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Electrode Array ◽  
Bacterial Biofilms ◽  
Long Tail ◽  
New Frontier ◽  
Electrical Signalling ◽  
Spatio Temporal ◽  
Biofilm Development

In nature, biofilms are the most common form of bacterial growth. In biofilms, bacteria display coordinated behaviour to perform specific functions. Here, we investigated electrical signalling as a possible driver in biofilm sociobiology. Using a multi-electrode array system that enables high spatio-temporal resolution, we studied the electrical activity in two biofilm-forming strains and one non-biofilm-forming strain. The action potential rates monitored during biofilm-forming bacterial growth exhibited a one-peak maximum with a long tail, corresponding to the highest biofilm development. This peak was not observed for the non-biofilm-forming strain, demonstrating that the intensity of the electrical activity was not linearly related to the bacterial density, but was instead correlated with biofilm formation. Results obtained indicate that the analysis of the spatio-temporal electrical activity of bacteria during biofilm formation can open a new frontier in the study of the emergence of collective microbial behaviour.

scholarly journals Cellular L-arginine pools modulate c-di-GMP turnover and biofilm formation in Pseudomonas putida

2020 ◽  
Author(s):  
Laura Barrientos-Moreno ◽  
María Antonia Molina-Henares ◽  
María Isabel Ramos-González ◽  
Manuel Espinosa-Urgel
Keyword(s):  
Pseudomonas Putida ◽  
Biofilm Formation ◽  
Response Regulator ◽  
Second Messenger ◽  
Colony Morphology ◽  
Diguanylate Cyclase ◽  
Arginine Biosynthesis ◽  
Amino Acid Transport System ◽  
Metabolic Signal ◽  
Biofilm Development

<p>The intracellular second messenger cyclic diguanylate (c-di-GMP) is broadly conserved in bacteria, where it influences processes such as virulence, stress resistance and biofilm development. In the plant-beneficial bacterium <em>Pseudomonas putida</em> KT2440, the response regulator with diguanylate cyclase activity CfcR is the main contributor to c-di-GMP levels in the stationary phase of growth. When overexpressed, CfcR increases c-di-GMP levels and gives rise to a pleiotropic phenotype that includes enhanced biofilm formation and crinkly colony morphology. Our group has previously reported that insertion mutants in <em>argG</em> and <em>argH</em>, the genes that encode the last two enzymes in the arginine biosynthesis pathway, do not display the crinkly colony morphology phenotype and show decreased c-di-GMP levels even in the presence of <em>cfcR</em> in multicopy (Ramos-González, M.I. <em>et al.</em> 2016. Front. Microbiol. 7, 1093). Here we present results indicating that L-arginine acts both as an environmental and as a metabolic signal that influences the lifestyles of <em>P. putida</em> through the modulation of c-di-GMP levels and changes in the expression of structural elements of biofilms. Exogenous L-arginine partially restores c-di-GMP levels in arginine biosynthesis mutants, a response that is transduced through CfcR and possibly (an)other diguanylate cyclase(s). At least three periplasmic binding proteins, each forming part of an amino acid transport system, contribute in different ways to the response to external L-arginine. We propose that the turnover of the second messenger c-di-GMP is modulated by the state of global arginine pools in the cell resulting both from anabolism and from uptake.</p>

scholarly journals Bacteriophages as an Alternative Strategy for Fighting Biofilm Development

2014 ◽  
Vol 63 (2) ◽  
pp. 137-145 ◽  
Author(s):  
SYLWIA PARASION ◽  
MAGDALENA KWIATEK ◽  
ROMUALD GRYKO ◽  
LIDIA MIZAK ◽  
ANNA MALM
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Bacterial Resistance ◽  
Bacterial Species ◽  
Experimental Studies ◽  
Alternative Methods ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Coagulase Negative Staphylococci ◽  
Biofilm Development

The ability of microbes to form biofilms is an important element of their pathogenicity, and biofilm formation is a serious challenge for today's medicine. Fighting the clinical complications associated with biofilm formation is very difficult and linked to a high risk of failure, especially in a time of increasing bacterial resistance to antibiotics. Bacterial species most commonly isolated from biofilms include coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter spp. The frequent failure of antibiotic therapy led researchers to look for alternative methods and experiment with the use of antibacterial factors with a mechanism of action different from that of antibiotics. Experimental studies with bacteriophages and mixtures thereof, expressing lytic properties against numerous biofilm-forming bacterial species showed that bacteriophages may both prevent biofilm formation and contribute to eradication of biofilm bacteria. A specific role is played here by phage depolymerases, which facilitate the degradation of extracellular polymeric substances (EPS) and thus the permeation of bacteriophages into deeper biofilm layers and lysis of the susceptible bacterial cells. Much hope is placed in genetic modifications of bacteriophages that would allow the equipping bacteriophages with the function of depolymerase synthesis. The use of phage cocktails prevents the development of phage-resistant bacteria.

scholarly journals Benefits and Drawbacks of Harboring Plasmid pP32BP2, Identified in Arctic Psychrophilic Bacterium Psychrobacter sp. DAB_AL32B

2019 ◽  
Vol 20 (8) ◽  
pp. 2015 ◽  
Author(s):  
Anna Ciok ◽  
Adrian Cegielski ◽  
Dariusz Bartosik ◽  
Lukasz Dziewit
Keyword(s):  
Bacterial Growth ◽  
Biofilm Formation ◽  
Psychrophilic Bacterium ◽  
Bacterial Cells ◽  
Cold Environments ◽  
Abiotic Surfaces ◽  
Measurable Activity ◽  
Alternative Carbon Source ◽  
The One ◽  
Aerobic And Anaerobic

Psychrobacter sp. DAB_AL32B, originating from Spitsbergen island (Arctic), carries the large plasmid pP32BP2 (54,438 bp). Analysis of the pP32BP2 nucleotide sequence revealed the presence of three predicted phenotypic modules that comprise nearly 30% of the plasmid genome. These modules appear to be involved in fimbriae synthesis via the chaperone-usher pathway (FIM module) and the aerobic and anaerobic metabolism of carnitine (CAR and CAI modules, respectively). The FIM module was found to be functional in diverse hosts since it facilitated the attachment of bacterial cells to abiotic surfaces, enhancing biofilm formation. The CAI module did not show measurable activity in any of the tested strains. Interestingly, the CAR module enabled the enzymatic breakdown of carnitine, but this led to the formation of the toxic by-product trimethylamine, which inhibited bacterial growth. Thus, on the one hand, pP32BP2 can enhance biofilm formation, a highly advantageous feature in cold environments, while on the other, it may prevent bacterial growth under certain environmental conditions. The detrimental effect of harboring pP32BP2 (and its CAR module) seems to be conditional, since this replicon may also confer the ability to use carnitine as an alternative carbon source, although a pathway to utilize trimethylamine is most probably necessary to make this beneficial. Therefore, the phenotype determined by this CAR-containing plasmid depends on the metabolic background of the host strain.

scholarly journals The Enterococcus faecalis fsr Two-Component System Controls Biofilm Development through Production of Gelatinase

2004 ◽  
Vol 186 (17) ◽  
pp. 5629-5639 ◽  
Author(s):  
Lynn E. Hancock ◽  
Marta Perego
Keyword(s):  
Enterococcus Faecalis ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Heart Valves ◽  
Bacterial Resistance ◽  
Two Component System ◽  
Component System ◽  
Abiotic Surfaces ◽  
Two Component ◽  
Biofilm Development

ABSTRACT Bacterial growth as a biofilm on solid surfaces is strongly associated with the development of human infections. Biofilms on native heart valves (infective endocarditis) is a life-threatening disease as a consequence of bacterial resistance to antimicrobials in such a state. Enterococci have emerged as a cause of endocarditis and nosocomial infections despite being normal commensals of the gastrointestinal and female genital tracts. We examined the role of two-component signal transduction systems in biofilm formation by the Enterococcus faecalis V583 clinical isolate and identified the fsr regulatory locus as the sole two-component system affecting this unique mode of bacterial growth. Insertion mutations in the fsr operon affected biofilm formation on two distinct abiotic surfaces. Inactivation of the fsr-controlled gene gelE encoding the zinc-metalloprotease gelatinase was found to prevent biofilm formation, suggesting that this enzyme may present a unique target for therapeutic intervention in enterococcal endocarditis.

scholarly journals Urethane Dimethacrylate Influences the Cariogenic Properties of Streptococcus Mutans

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1015
Author(s):  
Kyungsun Kim ◽  
Jeong Nam Kim ◽  
Bum-Soon Lim ◽  
Sug-Joon Ahn
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Early Stage ◽  
Biological Effects ◽  
Sugar Transport ◽  
Composite Resins ◽  
Dental Composite ◽  
Bacterial Cells ◽  
Urethane Dimethacrylate ◽  
Biofilm Development

Concerns regarding unbound monomers in dental composites have increased with the increased usage of these materials. This study assessed the biological effects of urethane dimethacrylate (UDMA), a common monomer component of dental composite resins, on the cariogenic properties of Streptococcus mutans. Changes in the growth rate, biofilm formation, interaction with saliva, surface hydrophobicity, adhesion, glucan synthesis, sugar transport, glycolytic profiles, and oxidative- and acid-stress tolerances of S. mutans were evaluated after growing the cells in the presence and absence of UDMA. The results indicated that UDMA promotes the adhesion of S. mutans to the underlying surfaces and extracellular polysaccharide synthesis, leading to enhanced biofilm formation. Furthermore, UDMA reduced the acid tolerance of S. mutans, but enhanced its tolerance to oxidative stress, thus favoring the early stage of biofilm development. UDMA did not significantly affect the viability or planktonic growth of cells, but diminished the ability of S. mutans to metabolize carbohydrates and thus maintain the level of intracellular polysaccharides, although the tendency for sugar transport increased. Notably, UDMA did not significantly alter the interactions of bacterial cells with saliva. This study suggests that UDMA may potentially contribute to the development of secondary caries around UDMA-containing dental materials by prompting biofilm formation, enhancing oxidative tolerance, and modulating carbon flow.

scholarly journals Role of Multicellular Aggregates in Biofilm Formation

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Kasper N. Kragh ◽  
Jaime B. Hutchison ◽  
Gavin Melaugh ◽  
Chris Rodesney ◽  
Aled E. L. Roberts ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Single Cells ◽  
Subsequent Development ◽  
Relative Fitness ◽  
Bacterial Cells ◽  
Ecological Benefit ◽  
Multicellular Aggregates ◽  
Biofilm Development

ABSTRACT In traditional models of in vitro biofilm development, individual bacterial cells seed a surface, multiply, and mature into multicellular, three-dimensional structures. Much research has been devoted to elucidating the mechanisms governing the initial attachment of single cells to surfaces. However, in natural environments and during infection, bacterial cells tend to clump as multicellular aggregates, and biofilms can also slough off aggregates as a part of the dispersal process. This makes it likely that biofilms are often seeded by aggregates and single cells, yet how these aggregates impact biofilm initiation and development is not known. Here we use a combination of experimental and computational approaches to determine the relative fitness of single cells and preformed aggregates during early development of Pseudomonas aeruginosa biofilms. We find that the relative fitness of aggregates depends markedly on the density of surrounding single cells, i.e., the level of competition for growth resources. When competition between aggregates and single cells is low, an aggregate has a growth disadvantage because the aggregate interior has poor access to growth resources. However, if competition is high, aggregates exhibit higher fitness, because extending vertically above the surface gives cells at the top of aggregates better access to growth resources. Other advantages of seeding by aggregates, such as earlier switching to a biofilm-like phenotype and enhanced resilience toward antibiotics and immune response, may add to this ecological benefit. Our findings suggest that current models of biofilm formation should be reconsidered to incorporate the role of aggregates in biofilm initiation. IMPORTANCE During the past decades, there has been a consensus around the model of development of a biofilm, involving attachment of single planktonic bacterial cells to a surface and the subsequent development of a mature biofilm. This study presents results that call for a modification of this rigorous model. We show how free floating biofilm aggregates can have a profound local effect on biofilm development when attaching to a surface. Our findings show that an aggregate landing on a surface will eventually outcompete the biofilm population arising from single cells attached around the aggregate and dominate the local biofilm development. These results point to a regime where preformed biofilm aggregates may have a fitness advantage over planktonic cells when it comes to accessing nutrients. Our findings add to the increasingly prominent comprehension that biofilm lifestyle is the default for bacteria and that planktonic single cells may be only a transition state at the most.

scholarly journals BolA Is a Transcriptional Switch That Turns Off Motility and Turns On Biofilm Development

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Clémentine Dressaire ◽  
Ricardo Neves Moreira ◽  
Susana Barahona ◽  
António Pedro Alves de Matos ◽  
Cecília Maria Arraiano
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Extracellular Polysaccharides ◽  
Bacterial Cells ◽  
Content Type ◽  
Bacterial Transcription ◽  
A Genome ◽  
Exact Function ◽  
Transcriptional Switch ◽  
Biofilm Development

ABSTRACTBacteria are extremely versatile organisms that rapidly adapt to changing environments. When bacterial cells switch from planktonic growth to biofilm, flagellum formation is turned off and the production of fimbriae and extracellular polysaccharides is switched on. BolA is present in most Gram-negative bacteria, and homologues can be found from proteobacteria to eukaryotes. Here, we show that BolA is a new bacterial transcription factor that modulates the switch from a planktonic to a sessile lifestyle. It negatively modulates flagellar biosynthesis and swimming capacity inEscherichia coli. Furthermore, BolA overexpression favors biofilm formation, involving the production of fimbria-like adhesins and curli. Our results also demonstrate that BolA is a protein with high affinity to DNA and is able to regulate many genes on a genome-wide scale. Moreover, we show that the most significant targets of this protein involve a complex network of genes encoding proteins related to biofilm development. Herein, we propose that BolA is a motile/adhesive transcriptional switch, specifically involved in the transition between the planktonic and the attachment stage of biofilm formation.IMPORTANCEEscherichia colicells possess several mechanisms to cope with stresses. BolA has been described as a protein important for survival in late stages of bacterial growth and under harsh environmental conditions. BolA-like proteins are widely conserved from prokaryotes to eukaryotes. Although their exact function is not fully established at the molecular level, they seem to be involved in cell proliferation or cell cycle regulation. Here, we unraveled the role of BolA in biofilm development and bacterial motility. Our work suggests that BolA actively contributes to the decision of bacteria to arrest flagellar production and initiate the attachment to form structured communities, such as biofilms. The molecular studies of different lifestyles coupled with the comprehension of the BolA functions may be an important step for future perspectives, with health care and biotechnology applications.

scholarly journals Low-Field Nuclear Magnetic Resonance Characteristics of Biofilm Development Process

2021 ◽  
Vol 9 (12) ◽  
pp. 2466
Author(s):  
Yajun Zhang ◽  
Yusheng Lin ◽  
Xin Lv ◽  
Aoshu Xu ◽  
Caihui Feng ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Biofilm Formation ◽  
Development Process ◽  
Bacterial Cells ◽  
T2 Relaxation ◽  
Biofilm Growth ◽  
Low Field ◽  
Biofilm Development ◽  
Nuclear Magnetic

To in situ and noninvasively monitor the biofilm development process by low-field nuclear magnetic resonance (NMR), experiments should be made to determine the mechanisms responsible for the T2 signals of biofilm growth. In this paper, biofilms were cultivated in both fluid media and saturated porous media. T2 relaxation for each sample was measured to investigate the contribution of the related processes to T2 relaxation signals. In addition, OD values of bacterial cell suspensions were measured to provide the relative number of bacterial cells. We also obtained SEM photos of the biofilms after vacuum freeze-drying the pure sand and the sand with biofilm formation to confirm the space within the biofilm matrix and identify the existence of biofilm formation. The T2 relaxation distribution is strongly dependent on the density of the bacterial cells suspended in the fluid and the stage of biofilm development. The peak time and the peak percentage can be used as indicators of the biofilm growth states.

scholarly journals Contribution of alginate and levan production to biofilm formation by Pseudomonas syringae

Microbiology ◽  
2006 ◽  
Vol 152 (10) ◽  
pp. 2909-2918 ◽  
Author(s):  
Heike Laue ◽  
Alexander Schenk ◽  
Hongqiao Li ◽  
Lotte Lambertsen ◽  
Thomas R. Neu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Pseudomonas Syringae ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Time Course ◽  
Complex Structure ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Cells ◽  
Biofilm Development

Exopolysaccharides (EPSs) play important roles in the attachment of bacterial cells to a surface and/or in building and maintaining the three-dimensional, complex structure of bacterial biofilms. To elucidate the spatial distribution and function of the EPSs levan and alginate during biofilm formation, biofilms of Pseudomonas syringae strains with different EPS patterns were compared. The mucoid strain PG4180.muc, which produces levan and alginate, and its levan- and/or alginate-deficient derivatives all formed biofilms in the wells of microtitre plates and in flow chambers. Confocal laser scanning microscopy with fluorescently labelled lectins was applied to investigate the spatial distribution of levan and an additional as yet unknown EPS in flow-chamber biofilms. Concanavalin A (ConA) bound specifically to levan and accumulated in cell-depleted voids in the centres of microcolonies and in blebs. No binding of ConA was observed in biofilms of the levan-deficient mutants or in wild-type biofilms grown in the absence of sucrose as confirmed by an enzyme-linked lectin-sorbent assay using peroxidase-linked ConA. Time-course studies revealed that expression of the levan-forming enzyme, levansucrase, occurred mainly during early exponential growth of both planktonic and sessile cells. Thus, accumulation of levan in biofilm voids hints to a function as a nutrient storage source for later stages of biofilm development. The presence of a third EPS besides levan and alginate was indicated by binding of the lectin from Naja mossambica to a fibrous structure in biofilms of all P. syringae derivatives. Production of the as yet uncharacterized additional EPS might be more important for biofilm formation than the syntheses of levan and alginate.

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