The effects of extrinsic factors on the structural and mechanical properties of Pseudomonas fluorescens biofilms: A combined study of nutrient concentrations and shear conditions

Allen, Ashley; Habimana, Olivier; Casey, Eoin

doi:10.1016/j.colsurfb.2018.02.035

Cited by 32 publications

(18 citation statements)

References 48 publications

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“…This suggest the formation of a thinner and denser biofilm under stirring conditions. [45] Electrochemical methods are not sufficient to inform about the biofilm structure, and future work should include microscopy imaging to strengthen the correlation between dynamic/static conditions and biofilm structure. However, there was no significant difference between the three microstructures, likely because of the low repeatability of the results under stirring conditions.…”

Section: Resultsmentioning

confidence: 99%

“…The greatest effect of stirring was observed at 8 h (Figure ), when the R ct of the stirred biofilms was lower than that of the unstirred experiments. This suggest the formation of a thinner and denser biofilm under stirring conditions . Electrochemical methods are not sufficient to inform about the biofilm structure, and future work should include microscopy imaging to strengthen the correlation between dynamic/static conditions and biofilm structure.…”

Section: Resultsmentioning

confidence: 99%

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Electrochemical Signature of Escherichia coli on Nickel Micropillar Array Electrode for Early Biofilm Characterization

Astorga

Marsili

et al. 2019

ChemElectroChem

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Biofilms are sessile microbial communities living at interfaces, in which the extracellular matrix is responsible for the mechanical stability and adhesion to surfaces. Transition from planktonic to attached cells is a key step in the biofilm formation process. Monitoring of this transition is needed to prevent contamination of biomedical devices and mitigate microbially influenced corrosion. Under anoxic local conditions and in the presence of an exogenous redox mediator, biofilms can divert part of the electron flow associated with catabolism to electrodes maintained at a defined potential. Extracellular electron transfer (EET) follows upon the attachment of planktonic cells to the surface. Modification of the electrode increases bacterial attachment, thus allowing early bioelectrochemical detection of the biofilm. Here, we report a Ni electrode micropillar array to detect early attachment of Escherichia coli biofilm through mediated EET in potentiostat‐controlled electrochemical cells. The biofilm‐surface interaction is studied by using electrochemical impedance spectroscopy (EIS) at different potentials and temperatures over 24 h. The analysis of the EIS signature highlights the effect of temperature on mediated EET in biofilms. These results demonstrate that micropillared electrodes allow earlier biofilm detection than flat electrodes, which is relevant to biofilm sensing and investigation of microbially influenced corrosion in drinking water systems and biomedical devices.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Electrochemical Signature of Escherichia coli on Nickel Micropillar Array Electrode for Early Biofilm Characterization

Astorga

Marsili

et al. 2019

ChemElectroChem

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“…Amongst the parameters that affect biofilm development, physicochemical factors related with the surface (Crawford et al ., ) and flow velocity and shear rate (Allen et al ., ) are some of the most important. There is evidence that shear forces affect not only biofilm structure but also composition, mass transfer, exopolysaccharides production, energy metabolism and can also induce genetic or molecular changes in biofilms (Moreira et al ., ).…”

Section: Introductionmentioning

confidence: 99%

Biofilm formation behaviour of marine filamentous cyanobacterial strains in controlled hydrodynamic conditions

Romeu

Alves

Morais

et al. 2019

Environmental Microbiology

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Summary Marine biofouling has severe economic impacts and cyanobacteria play a significant role as early surface colonizers. Despite this fact, cyanobacterial biofilm formation studies in controlled hydrodynamic conditions are scarce. In this work, computational fluid dynamics was used to determine the shear rate field on coupons that were placed inside the wells of agitated 12‐well microtiter plates. Biofilm formation by three different cyanobacterial strains was assessed at two different shear rates (4 and 40 s−1) which can be found in natural ecosystems and using different surfaces (glass and perspex). Biofilm formation was higher under low shear conditions, and differences obtained between surfaces were not always statistically significant. The hydrodynamic effect was more noticeable during the biofilm maturation phase rather than during initial cell adhesion and optical coherence tomography showed that different shear rates can affect biofilm architecture. This study is particularly relevant given the cosmopolitan distribution of these cyanobacterial strains and the biofouling potential of these organisms.

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“…They have one order of magnitude less than expansion rates from matrix and transmission channels, as shown in Figure . Allen, Habimana, & Casey, () found that the biofilm becomes soft and has lower elastic modulus when the biofilm grows under higher nutrient concentration, which makes the biofilm growth easier, and accordingly the biofilm has a large expansion velocity with more nutrient.…”

Section: Resultsmentioning

confidence: 99%

Dependence of the Bacillus subtilis biofilm expansion rate on phenotypes and the morphology under different growing conditions

et al. 2019

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Biofilms are communities of tightly associated bacteria encased in an extracellular matrix and attached to surfaces of various objects, such as liquid or solid surfaces. Here we use the multi‐channel wide field stereo fluorescence microscope to characterize growth of the Bacillus subtilis biofilm, in which the bacterial strain was triple fluorescence labeled for three main phenotypes: motile, matrix producing and sporulating cells. We used the feature point matching approach analyzing time lapse experimental movies to study the biofilm expansion rate. We found that the matrix producing cells dominate the biofilm expansion, at the biofilm edge, the expansion rate of matrix producing cells was almost the same as the velocity of the whole biofilm; however, the motile and sporulating cells were nearly rest. We also found that the biofilm expansion rate evolution relates to cell differentiation and biofilm morphology, and other micro‐environments can influence the biofilm growth, such as nutrient, substrate hardness and colony competition. From our work, we get a deeper understanding of the biofilm growth, which can help us to control and to further disperse the biofilm.

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The effects of extrinsic factors on the structural and mechanical properties of Pseudomonas fluorescens biofilms: A combined study of nutrient concentrations and shear conditions

Cited by 32 publications

References 48 publications

Electrochemical Signature of Escherichia coli on Nickel Micropillar Array Electrode for Early Biofilm Characterization

Electrochemical Signature of Escherichia coli on Nickel Micropillar Array Electrode for Early Biofilm Characterization

Biofilm formation behaviour of marine filamentous cyanobacterial strains in controlled hydrodynamic conditions

Dependence of the Bacillus subtilis biofilm expansion rate on phenotypes and the morphology under different growing conditions

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