Physiological methods to study biofilm disinfection

McFeters, Gordon A.; Yu, Feipeng Philip; Pyle, Barry H.; Stewart, Philip S.

doi:10.1007/bf01569988

Cited by 28 publications

(9 citation statements)

References 33 publications

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“…The action of OPA on the respiratory activity of the biofilm was evaluated by determining the oxygen uptake rate due to glucose oxidation, which according to Stewart et al (1994) and McFeters et al (1995) may be more accurate than the traditional method of colony formation on agar medium. This latter method has received much criticism especially when used to evaluate the effect of the antimicrobial agents (MacDonald et al, 2000).…”

Section: Resultsmentioning

confidence: 99%

“…In all cases, biocide efficiency was evaluated through plate counting techniques, which may overestimate OPA action since cells may remain viable after biocide treatment, but because they are stressed they may not able to grow on solid growth media (Stewart et al, 1994;McFeters et al, 1995) or may aggregate leading to the underestimation of the culturable cells. Recently, Simõ es et al (2003b) demonstrated that the disinfection action of OPA was substantially reduced for biofilms formed under low shear compared to suspended bacteria.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Different Concentrations ofOrtho-phthalaldehyde on Biofilms Formed byPseudomonas fluorescensUnder Different Flow Conditions

Simões¹,

Vieira²

2003

Biofouling

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The effectiveness of different concentrations of ortho-phthalaldehyde (OPA) in controlling biofilms of Pseudomonas fluorescens formed on stainless steel slides, using flow cell reactors under laminar and turbulent flow, was investigated by determining the variation in mass and respiratory activity. The physical stability of the biofilm with and without exposure to OPA was studied in a rotating device as variation in the mass of the biofilm on the surface after exposure to different rotation velocities. The activity of OPA against bacterial suspended cultures was evaluated in the presence and absence of bovine serum albumin (BSA) in order to evaluate the interference of proteins on the activity of the biocide. The results showed that biofilms formed under different flow conditions had different properties and reacted differently after biocide application. Biofilms formed under laminar flow were more easily inactivated than those formed under turbulent conditions. However, OPA did not promote the detachment of biofilms from the surface. The exposure of biofilms to different shear stress conditions after OPA treatment enhanced removal from the surface, indicating that OPA may weaken the biofilm matrix. The biocide was more effective on suspended cells than on cells grown in biofilms. This fact may be explained by the reaction of the biocide with proteins of the polymeric matrix of the biofilm as suggested by the significant reduction of biocide action on suspended cells in the presence of BSA.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of Different Concentrations ofOrtho-phthalaldehyde on Biofilms Formed byPseudomonas fluorescensUnder Different Flow Conditions

Simões¹,

Vieira²

2003

Biofouling

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“…Kaprelyants and Kell (55) showed that by use of FCM, Micrococcus luteus cells could be divided in viable, non-viable, and non-viable but resuscitable cell populations. McFeters and co-workers used rhodamine 123 to assess the physiological activity of bacteria in biofilms (79,152,153). They compared the rhodamine assay with the DVC (nalidixic acid) method, CTC reduction, RNA turnover, and plate count method.…”

Section: Flow Cytometrymentioning

confidence: 99%

Assessment of viability of microorganisms employing fluorescence techniques

Breeuwer

Abee

2000

International Journal of Food Microbiology

264

181

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“…The increase in organic matter at increasing glucose concentrations suggests that after covering the membrane surface, biofilm growth and accumulation happened in the vertical direction, i.e., in thickness. This cannot be verified since epifluorescence microscopy, although an established technology for viewing biofilms on surfaces, is limited in its applicability for analyzing thickness [31]. However, considering the conditions set for Run A and Run B were different, the SS deposition mechanism might be different in the two runs.…”

Section: Interaction Between Biofilm and Suspended Solidsmentioning

confidence: 99%

Effect of Biofilm on Inorganic Suspended Solids Accumulation on Reverse Osmosis Membranes

Manalo

Ohno

Okuda

et al. 2016

J. of Wat. & Envir. Tech.

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Particles and colloids in feedwater for reverse osmosis (RO) processes are typically removed by pretreatment to silt density index allowable levels to prevent accumulation on membranes. However, the accumulation is mostly caused due to combined biofouling-particulate accumulation and it is important to quantitatively understand particle accumulation as affected by biofilm. This study aims to determine the effect of biofilm on the accumulation of inorganic suspended solids on RO membranes. With the same kaolin concentration contained on the feedwater, the amount of inorganic material deposited was greater by 0.16 mg/cm 2 when secondary effluent water was used in contrast to pure water, signifying quantitative enhancement of accumulated suspended solid (SS) on the membrane. Amount of glucose in feedwater did not result in a related increase in inorganic material since deposition seemed to be influenced by biofilm coverage on a preformed biofilm, as indicated by similar biofilm percentage coverage with and without glucose in feedwater. Micrographs indicated the preferential deposition of SS on the spacer filaments and membrane areas that were covered with biofilm. This effect of biofilm on inorganic SS accumulation will be highly useful in designing pretreatment strategies by addressing biofilm control to prevent both biofilm formation and SS accumulation.

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Physiological methods to study biofilm disinfection

Cited by 28 publications

References 33 publications

Effect of Different Concentrations ofOrtho-phthalaldehyde on Biofilms Formed byPseudomonas fluorescensUnder Different Flow Conditions

Effect of Different Concentrations ofOrtho-phthalaldehyde on Biofilms Formed byPseudomonas fluorescensUnder Different Flow Conditions

Assessment of viability of microorganisms employing fluorescence techniques

Effect of Biofilm on Inorganic Suspended Solids Accumulation on Reverse Osmosis Membranes

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