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Effects of Carbon Dioxide Aerosols on the Viability of Escherichia coli during Biofilm Dispersal.

Singh R, Monnappa AK, Hong S, Mitchell RJ, Jang J - Sci Rep (2015)

Bottom Line: A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces.Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet.In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, S. Korea.

ABSTRACT
A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces. However, the impact of the aerosols on the viability of bacteria during treatment has never been evaluated. In this study, the effects of high-speed CO2 aerosols, a mixture of solid and gaseous CO2, on bacteria viability was studied. It was found that when CO2 aerosols were used to disperse biofilms of Escherichia coli, they led to a significant loss of viability, with approximately 50% of the dispersed bacteria killed in the process. By comparison, 75.6% of the biofilm-associated bacteria were viable when gently dispersed using Proteinase K and DNase I. Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet. In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm. As such, these CO2 aerosols not only remove biofilm-associated bacteria effectively but also significantly impact their viability by disrupting membrane integrity.

No MeSH data available.


Related in: MedlinePlus

SEM images showing the effects of a treatment with either CO2 aerosols or hydrolytic enzymes on the E. coli biofilms grown for one day.(a) Untreated control chip showing the presence of an extensive E. coli biofilm on the Si surface. (b) Biofilm after CO2 aerosol treatment. (c) Image of E. coli biofilm after being soaked in 25 mM HEPES buffer for two hours. (d) E. coli biofilm after treatment with HEPES buffer containing both Proteinase K and DNase I.
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f1: SEM images showing the effects of a treatment with either CO2 aerosols or hydrolytic enzymes on the E. coli biofilms grown for one day.(a) Untreated control chip showing the presence of an extensive E. coli biofilm on the Si surface. (b) Biofilm after CO2 aerosol treatment. (c) Image of E. coli biofilm after being soaked in 25 mM HEPES buffer for two hours. (d) E. coli biofilm after treatment with HEPES buffer containing both Proteinase K and DNase I.

Mentions: SEM analysis was initially used to analyze E. coli biofilms grown for one day on silicon chips before and after treating them with CO2 aerosols or hydrolytic enzymes (Fig. 1). This figure shows that a uniform growth of E. coli biofilm across the silicon surface was readily apparent for the control chip (Fig. 1a) and that this biofilm was effectively removed after the CO2 aerosol treatment (Fig. 1b). For comparison, an SEM micrograph of the E. coli biofilm after soaking in HEPES buffer is also presented (Fig. 1c) along with an image showing the E. coli biofilm after treatment with both Proteinase K and DNase I (Fig. 1d). As these two enzymes hydrolyze the protein and DNA present within the EPS, treatment of the biofilms with both of these results in a gentle dispersion of the bacteria.


Effects of Carbon Dioxide Aerosols on the Viability of Escherichia coli during Biofilm Dispersal.

Singh R, Monnappa AK, Hong S, Mitchell RJ, Jang J - Sci Rep (2015)

SEM images showing the effects of a treatment with either CO2 aerosols or hydrolytic enzymes on the E. coli biofilms grown for one day.(a) Untreated control chip showing the presence of an extensive E. coli biofilm on the Si surface. (b) Biofilm after CO2 aerosol treatment. (c) Image of E. coli biofilm after being soaked in 25 mM HEPES buffer for two hours. (d) E. coli biofilm after treatment with HEPES buffer containing both Proteinase K and DNase I.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561891&req=5

f1: SEM images showing the effects of a treatment with either CO2 aerosols or hydrolytic enzymes on the E. coli biofilms grown for one day.(a) Untreated control chip showing the presence of an extensive E. coli biofilm on the Si surface. (b) Biofilm after CO2 aerosol treatment. (c) Image of E. coli biofilm after being soaked in 25 mM HEPES buffer for two hours. (d) E. coli biofilm after treatment with HEPES buffer containing both Proteinase K and DNase I.
Mentions: SEM analysis was initially used to analyze E. coli biofilms grown for one day on silicon chips before and after treating them with CO2 aerosols or hydrolytic enzymes (Fig. 1). This figure shows that a uniform growth of E. coli biofilm across the silicon surface was readily apparent for the control chip (Fig. 1a) and that this biofilm was effectively removed after the CO2 aerosol treatment (Fig. 1b). For comparison, an SEM micrograph of the E. coli biofilm after soaking in HEPES buffer is also presented (Fig. 1c) along with an image showing the E. coli biofilm after treatment with both Proteinase K and DNase I (Fig. 1d). As these two enzymes hydrolyze the protein and DNA present within the EPS, treatment of the biofilms with both of these results in a gentle dispersion of the bacteria.

Bottom Line: A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces.Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet.In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm.

View Article: PubMed Central - PubMed

Affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, S. Korea.

ABSTRACT
A periodic jet of carbon dioxide (CO2) aerosols is a very quick and effective mechanical technique to remove biofilms from various substrate surfaces. However, the impact of the aerosols on the viability of bacteria during treatment has never been evaluated. In this study, the effects of high-speed CO2 aerosols, a mixture of solid and gaseous CO2, on bacteria viability was studied. It was found that when CO2 aerosols were used to disperse biofilms of Escherichia coli, they led to a significant loss of viability, with approximately 50% of the dispersed bacteria killed in the process. By comparison, 75.6% of the biofilm-associated bacteria were viable when gently dispersed using Proteinase K and DNase I. Indirect proof that the aerosols are damaging the bacteria was found using a recombinant E. coli expressing the cyan fluorescent protein, as nearly half of the fluorescence was found in the supernatant after CO2 aerosol treatment, while the rest was associated with the bacterial pellet. In comparison, the supernatant fluorescence was only 9% when the enzymes were used to disperse the biofilm. As such, these CO2 aerosols not only remove biofilm-associated bacteria effectively but also significantly impact their viability by disrupting membrane integrity.

No MeSH data available.


Related in: MedlinePlus