The impact of recombinant fusion-hydrophobin coated surfaces on E. coli and natural mixed culture biofilm formation

The impact of increased surface hydrophobicity on biofilms regarding retardation, repulsion, or attraction was studied with hydrophobin modified glass substrata. Recombinantly produced fungal hydrophobins forming self-assembled monolayers were used as the surface coating. The adsorption dynamics of hydrophobins were analysed with a quartz crystal microbalance which showed the surface coating to be rapid and stable. The change of surface wettability was determined by water contact angle measurements and demonstrated an increase in hydrophobicity in range of 60–62°. The homogeneity of the monolayers was demonstrated by immunofluorescence microscopy. Atomic force microscopy was applied to visualise the uniform texture of the coated materials. The hydrophobin coatings had no impact on different biofilms in terms of spatial distribution, cell numbers, and population composition. In consequence, hydrophobicity might not represent an important parameter for biofilm formation. Nevertheless, recombinant hydrophobins are suitable for large scale surface modification and functionalization with bioactive molecules.     

Impact of biological factors on the ennoblement of stainless steel in Baltic seawater

Open circuit potentials of stainless steels increased when immersed in the Baltic Sea. The ennoblement potential was +200 mV_sce in 40 to 50 days when sea water temperature was below 52°C and +300–400 mV_sce within <40 days at around 102°C. Ennoblement occurred in a laboratory ecosystem at 232°C in 20 to 30 days, and at 262°C in <20 days, but no ennoblement occurred at A322°C within 40 days. By the time the ennoblement was complete, compact microcolonies covered 1–10% of the steel surface. Nutrient enrichment of Baltic Sea water by twofold above the natural levels increased microbial growth but attenuated open circuit potential increase of the stainless steels. Exposure of the ennobled stainless steels to similar levels of nutrients did not reverse the already developed open circuit potentials. Attenuation of the ennobling response of the stainless steels by increases of temperature and eutrophication suggests a role for microorganisms which is crucial for the electrochemical behaviour of steels in brackish Baltic Sea water. Journal of Industrial Microbiology & Biotechnology (2000) 24, 410–420. Received 02 November 1999/ Accepted in revised form 24 March 2000     

Evaluation of the effect of cleaning regimes on biofilms of thermophilic bacilli on stainless steel

AIMS: To determine the mechanism for both the removal and inactivation of 18-h biofilms of a thermophilic Bacillus species that optimally grows at 55 degrees C on stainless steel. METHODS AND RESULTS: The cleaning strategies tested were based on biofilm biochemistry and physiology, and focused on the chemistry of the cleaners, the duration and temperature of the cleaning process and a combination of various cleaners. The success of the cleaning regimes was determined based on the removal of cells and organic debris and the elimination of viable cells. The results confirmed that a caustic (75 degrees C for 30 min) and acid (75 degrees C for 30 min) wash, relied upon heavily in most food processing industries for cleaning-in-place systems, was successful in removing these biofilms. However, any changes in the concentrations of these cleaners or the temperature of cleaning drastically affected the overall outcome. Alternative cleaning agents based on enzymatic or nonenzymatic breakdown of cellular proteins or polysaccharides, surfactant action, use of oxidative attack and free radicals varied in degrees of their success. Combining proteolytic action with surfactants increased wetability and therefore enhanced the cleaning efficiency. CONCLUSIONS: Several procedures, including caustic/acid and enzyme based cleaners, will be satisfactory, provided that the correct process parameters are observed i.e. concentration, time, temperature and kinetic energy (flow). Confirmation of these results should be carried out in a pilot plant through several use/clean cycles. SIGNIFICANCE AND IMPACT OF THE STUDY: Confidence in standard and alternative cleaning procedures for food manufacturing plant to prevent contamination with thermophilic bacilli that threaten product quality.     

In situ detection of bacteria involved in cathodic depolarization and stainless steel surface corrosion using microautoradiography

Aims: To examine the activity of bacteria involved in cathodic depolarization and surface corrosion on stainless steel in an in situ model system. Methods and Results: The microautoradiographic technique (MAR) was used to evaluate the activity of bacterial populations on stainless steel surfaces with a single cell resolution. Anaerobic uptake and fixation of ¹⁴C‐labelled bicarbonate occurred within corrosion sites in the absence of atmospheric hydrogen or other external electron donors, whereas it was taken up and fixed by bacteria at all other stainless steel surfaces in the presence of atmospheric hydrogen. This indicates that the bacteria utilized electrons originating from the corrosion sites due to the ongoing corrosion (cathodic depolarization). Conclusion: Under in situ conditions, bacteria were fixating ¹⁴C‐labelled bicarbonate at corrosion sites in the absence of atmospheric hydrogen. This indicates that electrons transferred to the bacteria provided energy for bicarbonate fixation due to cathodic depolarization. Significance and Impact of the Study: Application of the MAR method showed ongoing biocorrosion in the applied in situ model system and allowed in situ examination of bacterial activity on a single cell level directly on a metal surface providing information about potential corrosion mechanisms. Furthermore, application of fluorescence in situ hybridization in combination with MAR allows for identification of the active bacteria.     

Adhesion and removal kinetics of Bacillus cereus biofilms on Ni-PTFE modified stainless steel

Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm^?2. Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm^?2 of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment.     

AFM study of the colonisation of stainless steel by Aquabacterium commune

Aquabacterium commune, a member of the beta proteobacteria family that is a recently isolated, predominant member of various European drinking water distribution system biofilms, was selected as a test organism in this study. Attachment of A. commune cells onto two increasingly popular pipe materials, stainless steel EN1.4307 and medium density polyethylene (MDPE) was studied at 15 °C, 150 rpm, and a hydraulic retention time of 10.5 h in a rotating annular biofilm (RAB) reactor. Planktonic and sessile growth was monitored by spread plate technique. Atomic force microscopy (AFM) was used to obtain information about surface topography and biofilm formation pattern. Our study has shown that: (i) Steady-state conditions were reached after ca. 100 h for both materials; (ii) biofilm cell density on MDPE slides is four times greater than on stainless; (iii) the primary colonization of MDPE and stainless steel occurred at the edge of the slides; and (iv) no preferential attachment to stainless steel grain boundaries was observed. Stainless-steel manufacturers and suppliers, researchers, and companies working in the drinking-water sector will benefit from this paper. It is suggested that electropolishing of stainless-steel pipes for drinking water installations is not necessary to remove specific biofilm formation sites (i.e. grain boundaries). Furthermore, this paper provides, for the first time, some fundamental information for the continuous cultivation of the recently isolated drinking water microorganism, A. commune.     

Comparison of fluorinated polymers against stainless steel, glass and polypropylene in microbial biofilm adherence and removal

Biofilm formation is a long-standing problem in ultrapure water and bioprocess fluid transport lines. The standard materials used in these applications (316L stainless steel, polypropylene and glass) have long been known to be good surfaces for the attachment of bacteria and other biological materials. To compare the relative tenacity of biofilms grown on materials used in manufacturing processes, a model system for biofilm attachment was constructed that approximates the conditions in industrial process systems. New fluorinated polymers were compared to the above materials by evaluating the surface area coverage of bacterial populations on materials before and after mild chemical treatment. In addition, contact angle studies compared the relative hydrophobicity of surfaces to suspensions of bacteria in growth media, and scanning electron microscopy and atomic force microscopy studies were used to characterize surface smoothness and surface defects. Biofilm adherence to polymer-based substrata was determined to be a function of both surface finish and surface chemistry. Specifically, materials that are less chemically reactive, as indicated by higher contact angle, can have rougher surface finishes and still be amenable to biofilm removal. Received 20 March 1997/ Accepted in revised form 15 July 1997     

Development of silver-containing austenite antibacterial stainless steels for biomedical applications Part I: microstructure characteristics,mechanical properties and antibacterial mechanisms

The as-quenched (AQ) microstructure of the Ag-containing alloys was found to be essentially a mixture of austenite (γ) and Ag phases. The Ag phase precipitates had a face-centered-cubic structure and lattice parameter a = 4.09 Å. When the alloy contained Ag ≥0.2 wt%, the mechanical properties were slightly enhanced because of the precipitate strengthening by the Ag phase precipitates. Moreover, the Ag-containing alloys exhibited ductile fracture after tensile testing. The results of an antibacterial test revealed that the Ag phase precipitates play a key role in the antibacterial mechanism of Ag-containing alloys: Ag⁺ ions released from the Ag phase precipitates can kill bacteria. It is suggested that as AISI 316L alloy has an Ag content ≥0.2 wt%, it will have excellent antibacterial properties against both Staphylococcus aureus and Escherichia coli, with an antibacterial rate of nearly 100%.     

Anti-biofilm properties of the antimicrobial peptide temporin 1Tb and its ability,in combination with EDTA,to eradicate Staphylococcus epidermidis biofilms on silicone catheters

In search of new antimicrobials with anti-biofilm potential, in the present study activity of the frog-skin derived antimicrobial peptide temporin 1Tb (TB) against Staphylococcus epidermidis biofilms was investigated. A striking ability of TB to kill both forming and mature S. epidermidis biofilms was observed, especially when the peptide was combined with cysteine or EDTA, respectively. Kinetics studies demonstrated that the combination TB/EDTA was active against mature biofilms already after 2–4-h exposure. A double 4-h exposure of biofilms to TB/EDTA further increased the therapeutic potential of the same combination. Of note, TB/EDTA was able to eradicate S. epidermidis biofilms formed in vitro on silicone catheters. At eradicating concentrations, TB/EDTA did not cause hemolysis of human erythrocytes. The results shed light on the anti-biofilm properties of TB and suggest a possible application of the peptide in the lock therapy of catheters infected with S. epidermidis.     

Interactions between non-phospholipid liposomes containing cetylpyridinium chloride and biofilms of Streptococcus mutans: modulation of the adhesion and of the biodistribution

Cetylpyridinium chloride (CPC) is a surfactant that binds strongly to bacteria and bacterial biofilms. In this study, fluorescence-based techniques were used to determine the penetration and adhesion of CPC when it was introduced in liposomes. In spite of a reduced adhesion as compared to pure CPC micelles, CPC-containing liposomes adhered significantly to the biofilms of Streptococcus mutans. In contrast, no binding was observed for liposomes that were composed of phosphatidylcholine-cholesterol. The influence of the charge of the liposome on its adhesion to biofilms was studied using cholesterol (Chol) and cholesterol sulfate (Schol). In spite of similar binding to the biofilms, positively charged CPC/Chol liposomes were located mainly in the core of the biofilm microcolonies, whereas the negatively charged CPC/Schol liposomes were mainly concentrated at their periphery. This effect may be attributed to the different availability of the CPC head group. In summary, this work demonstrates the high potential for tailoring drug nanovectors by modulating sterol selection in order to selectively target and bind biofilms.     

Rapid reduction of Legionella pneumophila on stainless steel with zeolite coatings containing silver and zinc ions

AIMS: To determine the rate of reduction of Legionella pneumophila by stainless steel surfaces with zeolite ceramic coatings containing 2.5% (w/w) silver (Ag) and 14% zinc (Zn) ions. METHODS AND RESULTS: Stainless steel pans with and without Ag/Zn coatings were inoculated with solutions of Leg. pneumophila ATCC 33155 and incubated at 37 degrees C. Survival was monitored using the spread-plate technique on selective buffered charcoal yeast extract agar. Significant reductions of Leg. pneumophila were effected by the Ag/Zn zeolite coatings within 2 h of exposure. CONCLUSIONS, Significance and Impact of the Study: Zeolite ceramic Ag/Zn coatings impart significant anti-Legionella properties to stainless steel surfaces. Coated stainless steel could be used in the manufacture of air ducts, condensation pans and intake and exhaust vents. These products have the potential to reduce numbers of Legionella in air-handling systems.     

Influence of membrane surface properties on the behavior of initial bacterial adhesion and biofilm development onto nanofiltration membranes

In order to investigate biofouling problems, the fundamental behaviors of initial bacterial adhesion and biofilm development on four different nanofiltration (NF) membranes were evaluated using Pseudomonas aeruginosa PAO1 as a model bacterial strain. Initial cell adhesion was considerably higher on an aromatic polyamide-based NF membrane with a hydrophobic and rough surface, whereas cell aggregation on a polypiperazine-based NF membrane with a relatively hydrophilic and smooth surface was lower. Moreover, significant differences in the structural heterogeneity of the biofilms were observed among the four NF membranes. This study shows that the surface roughness and hydrophobicity of a membrane play an important role in determining initial cell adhesion, aggregation and favorable localization sites for colony formation. In addition, it was found that biofilm development was strongly influenced by the surface morphology of a membrane.     

Surface properties of bacteria sensitive and resistant to the class IIa carnobacteriocin Cbn BM1

Aims: Class IIa bacteriocins are small antimicrobial peptides synthesized by lactic acid bacteria. The proposed mechanisms of action for class IIa bacteriocins suggest that the physicochemical properties of the target bacterial surface govern the bacteriocin antimicrobial activity. The aim of this study is to decipher the relationship between both sensitivity and resistance to a class IIa bacteriocin, carnobacteriocin BM1 and physicochemical surface properties of bacteria. Methods and Results: The study was performed on 18 strains by a microbial adhesion to solvents process and with electrophoretic mobility measurements considering bacteria as soft particles. A large variation in bacterial surface properties is observed among the bacterial populations. Electro‐hydrodynamic parameters values appear to be more homogeneous for sensitive strains than for the resistant ones, which can exhibit more extreme values. Conclusions: Physicochemical surface properties of 18 strains determined show large variations between the strains. However, no direct link between these surface properties and the resistant/sensitive phenotypes of the strains can be stated. Significance and Impact of the Study: The surface physicochemical properties tested have a low predictive power to discriminate sensitive or resistant strains when determined at the bacterial population scale.     

Biofouling of stainless steel surfaces by four common pathogens: the effects of glucose concentration,temperature and surface roughness

There is a wide range of factors affecting bacterial adhesion and biofilm formation. However, in both food processing and medical settings, it is very hard to obtain suitably controlled conditions so that the factors that reduce surface colonisation and biofouling can be studied. The aim of this study was to evaluate the effect of glucose concentration, temperature and stainless steel (SS) surface roughness on biofouling by four common pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and L. monocytogenes). Among the tested variables, the untreated SS surface (3C) was shown to be fouled more than 3D polished, brushed or electropolished SS surfaces. Although an array of parameters influenced biofouling, the most promising control measure was the influence of low temperature (4?°C) that reduced biofouling even in the case of the psychrophilic Listeria monocytogenes. The study findings could significantly contribute to the prevention of SS surface contamination and consequential biofouling by food and healthcare associated pathogens.     

Inactivation of Escherichia coli O157:H7 in biofilm on stainless steel by treatment with an alkaline cleaner and a bacteriophage

AIMS: To determine the effectiveness of an alkaline cleaner used in food-processing plants and a lytic bacteriophage specific for Escherichia coli O157:H7 in killing wild type and rpoS-deficient cells of the pathogen in a biofilm. METHODS AND RESULTS: Wild type and rpoS-deficient cells were attached to stainless steel coupons (c. 7-8 log CFU per coupon) on which biofilms were developed during incubation at 22 degrees C for 96 h in M9 minimal salts media (MSM) with one transfer to fresh medium. Coupons were treated with 100 and 25% working concentrations of a commercial alkaline cleaner (pH 11.9, with 100 microg ml(-1) free chlorine) used in the food industry, chlorine solutions (50 and 100 microg ml(-1) free chlorine), or sterile deionized water (control) at 4 degrees C for 1 and 3 min. Treatment with 100% alkaline cleaners reduced populations by 5-6 log CFU per coupon, a significant (P < or = 0.05) reduction compared with treatment with water. Initial populations (2.6 log CFU per coupon) of attached cells of both strains were reduced by 1.2 log CFU per coupon when treated with bacteriophage KH1 (7.7 log PFU ml(-1)) for up to 4 days at 4 degrees C. Biofilms containing low populations (2.7-2.8 log CFU per coupon) of wild type and rpoS-deficient cells that had developed for 24 h at 22 degrees C were not decreased by more than 1 log CFU per coupon when treated with KH1 (7.5 log PFU ml(-1)) at 4 degrees C. CONCLUSIONS: Higher numbers of cells of E. coli O157:H7 in biofilms are killed by treatment with an alkaline cleaner than with hypochlorite alone, possibly through a synergistic mechanism of alkaline pH and hypochlorite. Populations of cells attached on coupons were reduced by treating with bacteriophage but cells enmeshed in biofilms were protected. SIGNIFICANCE AND IMPACT OF THE STUDY: The alkaline pH, in combination with hypochlorite, in a commercial cleaner is responsible for killing E. coli O157:H7 in biofilms. Treatment with bacteriophage KH1 reduces populations of cells attached to coupon surfaces but not cells in biofilms.     

Antimicrobial efficacy of the alkaloid harmaline alone and in combination with chlorhexidine digluconate against clinical isolates of Staphylococcus aureus grown in planktonic and biofilm cultures

Aims: To investigate the antimicrobial efficacy of an alkaloid, harmaline alone and in combination with chlorhexidine digluconate (CHG) against clinical isolates of Staphylococcus aureus (S. aureus) grown in planktonic and biofilm cultures. Methods: Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined for each micro‐organism grown in suspension and in biofilm using microbroth dilution method. Chequerboard assays were used to determine synergistic, indifferent or antagonistic interactions between harmaline and CHG, and the some of results were verified by confocal laser scanning microscopy. Results: Harmaline and CHG showed effective antimicrobial activity against suspensions and biofilm cultures of S. aureus, respectively. As determined by fractional inhibitory concentration index (FICI), synergistic antimicrobial effects between harmaline and CHG were observed in nine and 11 of the 13 S. aureus strains when in suspension and in biofilm, respectively. FICI values were from 0·375 to 1·25 when in suspension and from 0·25 to 1·25 when in biofilm. Conclusions: Synergistic activity of harmaline and CHG against clinical isolates of S. aureus (in suspension and in biofilm) was observed in vitro. Significance and Impact of the Study: This study might provide alternative methods to overcome the problem of drug‐resistance of S. aureus both in suspension and in biofilm.     

Enhanced biosynthesis of coagulation factor VIII through diminished engagement of the unfolded protein response

Human and porcine coagulation factor VIII (fVIII) display a biosynthetic efficiency differential that is being exploited for the development of new protein and gene transfer-based therapies for hemophilia A. The cellular and/or molecular mechanism(s) responsible for this phenomenon have yet to be uncovered, although it has been temporally localized to post-translational biosynthetic steps. The unfolded protein response (UPR) is a cellular adaptation to structurally distinct (e.g. misfolded) or excess protein in the endoplasmic reticulum and is known to be induced by heterologous expression of recombinant human fVIII. Therefore, it is plausible that the biosynthetic differential between human and porcine fVIII results from differential UPR activation. In the current study, UPR induction was examined in the context of ongoing fVIII expression. UPR activation was greater during human fVIII expression when compared with porcine fVIII expression as determined by ER response element (ERSE)-luciferase reporter activity, X-box-binding protein 1 (XBP1) splicing, and immunoglobulin-binding protein (BiP) up-regulation. Immunofluorescence microscopy of fVIII expressing cells revealed that human fVIII was notably absent in the Golgi apparatus, confirming that endoplasmic reticulum to Golgi transport is rate-limiting. In contrast, a significant proportion of porcine fVIII was localized to the Golgi indicating efficient transit through the secretory pathway. Overexpression of BiP, an integral UPR protein, reduced the secretion of human fVIII by 50%, but had no effect on porcine fVIII biosynthesis. In contrast, expression of BiP shRNA increased human fVIII expression levels. The current data support the model of differential engagement of UPR by human and porcine fVIII as a non-traditional mechanism for regulation of gene product biosynthesis.     

In vitro cytotoxicity studies of parent and nanoencapsulated Holmium-2,9-dimethyl-1,10-phenanthroline complex toward fish-salmon DNA-binding properties and antibacterial activity

Abstract

In this study, the interaction of Holmium (Ho) complex including 2, 9-dimethyl-1,10-phenanthroline, also called Neocuproine (Neo), [Ho(Neo)₂Cl₃.H₂O], as fluorescence probe with fish-salmon DNA (FS-DNA) is studied during experimental investigations. Multi-spectroscopic methods are utilized to determine the affinity binding constants (K_b) of complex–FS-DNA. It is found that fluorescence of Ho complex is strongly quenched by the FS-DNA through a static quenching procedure. Under optimal conditions in Tris(trishydroxymethyl-aminomethane)–HCl buffer at 25?°C with pH?≈?7.2, intrinsic binding constant K_b of Ho complex is 6.12?±?0.04?×?10⁵ M^?1. Also, the binding site number and Stern–Volmer quenching constant are calculated. There are different approaches, including iodide quenching assay, salt effect and thermodynamical assessment to determine the features of the binding mode between Ho complex and FS-DNA. Also, the parent and starch and lipid nanoencapsulated Ho complex, as potent antitumor candidates, were synthesized. The main structure of Ho complex is maintained after encapsulation using starch and lipid nanoparticles. 3-[4,5-Dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method was used to assess the anticancer properties of Ho complex and its encapsulated forms on human cancer cell lines of human lung carcinoma cell line and breast cancer cell line. In conclusion, these compounds could be considered as new antitumor candidates.

Communicated by Ramaswamy H. Sarma     

Enhanced expression of neurotensin/neuromedin N mRNA and products of NT/NMN precursor processing in neonatal rats

Intestinal levels of immunoreactive neurotensin (iNT) and neuromedin N (iNMN), as well as mRNA for the NT/NMN precursor, were elevated during the suckling period in rats. While transient expression of NT/NMN was observed at 1–5 days of age in the proximal small intestine and colon, NT/NMN levels in the ileum increased to peak at 10–20 days of age and then decreased to adult levels. The levels of these peptides were not elevated in the central nervous system and pituitary over this time period. Chromatographic analyses of jejunoileal extracts indicated that large molecular forms of iNT and iNMN were present, constituting 1.3% of total iNT and 56% of total iNMN, respectively. Treatment of the large forms with pepsin, which is known to generate the fully immunoreactive peptides, NT(3–13), NT(4–13), and NMN, increased immunoreactivity tenfold (iNT) and 1.2-fold (iNMN). Thus, large forms actually constituted 13% (iNT) and 60% (iNMN). Based upon its physicochemical properties, large molecular iNMN was tentatively identified as a 125 residue peptide with NMN at its C-terminus [i.e., rat prepro-NT/NMN(23–147)]. The properties of large molecular iNT were most similar to those predicted for the entire precursor [i.e., rat prepro-NT/NMN(23–169)]. These results indicate a) that enhanced expression of NT/NMN occurs in a tissue-specific manner in rats during the suckling period; b) that the pattern of precursor processing in intestine yields primarily NT and a large molecular form of NMN.     

Adaptational changes in cellular phospholipids and fatty acid composition of the food pathogen Listeria monocytogenes as a stress response to disinfectant sanitizer benzalkonium chloride

Aims: This study provides a first approach to observing the alterations of the cell membrane lipids in the adaptation response of Listeria monocytogenes to the sanitizer benzalkonium chloride. Methods and Results: A thorough investigation of the composition of polar and neutral lipids from L. monocytogenes grown when exposed to benzalkonium chloride is compared to cells optimally grown. The adaptation mechanism of L. monocytogenes in the presence of benzalkonium chloride caused (i) an increase in saturated‐chain fatty acids (mainly C_16:0 and C_18:0) and unsaturated fatty acids (mainly C_16:1 and C_18:1) at the expense of branched‐chain fatty acids (mainly C_a‐15:0 and C_a‐17:0) mainly because of neutral fatty acids; (ii) no alteration in the percentage of neutral and polar lipid content among total lipids; (iii) a decrease in lipid phosphorus and (iv) an obvious increase in the anionic phospholipids and a decrease in the amphiphilic phosphoaminolipid. Conclusions: These lipid changes could lead to decreased membrane fluidity and also to modifications of physicochemical properties of cell surface and thus changes in bacterial adhesion to abiotic surfaces. Significance and Impact of the Study: The adaptation and resistance of L. monocytogenes to disinfectants is able to change its physiology to allow growth in food‐processing plants. Understanding microbial stress response mechanisms would improve the effective use of disinfectants.