Person:
McLandsborough, Lynne

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Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Associate Professor, Department of Food Science
Last Name
McLandsborough
First Name
Lynne
Discipline
Food Science
Expertise
Bioactive food compounds
Food safety, biofilm formation and removal
Rapid detection methodology and food fermentations
Introduction
In general bacteria tend to accumulate at interfaces between two phases in heterogeneous systems. As long as water is available for microbial growth, microorganisms can be found foods and processing environments at solids-liquid, gas-liquid, and solid-gas interfaces. In their natural environments, bacteria do not exist as isolated cells but grow and survive in organized communities on surfaces. These communities are called biofilms and can be simplistically defined as bacterial growth on a solid surface. When growing in a biofilm, bacteria are known to have different growth rate, morphology, and physiology than their planktonic counterparts and may exhibit varied physiological responses to nutrient conditions resulting in increased resistance to antimicrobials agents compared with their planktonic forms.
Multispecies biofilms within food processing environments are a major source of L. monocytogenes in processed foods. When growing on surfaces, this organism exhibits enhanced resistance to conventional chemical sanitizers, germicides and heat making control even more challenging.
My laboratory is interested in multiple aspects of biofilms:
The genetics of Listeriasp. biofilm growth.
The biological, physical and chemical aspects of bacterial adhesion, transfer and removal.
The microbial diversity and ecology of biofilms within food processing environments.
In general bacteria tend to accumulate at interfaces between two phases in heterogeneous systems. As long as water is available for microbial growth, microorganisms can be found foods and processing environments at solids-liquid, gas-liquid, and solid-gas interfaces. In their natural environments, bacteria do not exist as isolated cells but grow and survive in organized communities on surfaces. These communities are called biofilms and can be simplistically defined as bacterial growth on a solid surface. When growing in a biofilm, bacteria are known to have different growth rate, morphology, and physiology than their planktonic counterparts and may exhibit varied physiological responses to nutrient conditions resulting in increased resistance to antimicrobials agents compared with their planktonic forms.
Multispecies biofilms within food processing environments are a major source of L. monocytogenes in processed foods. When growing on surfaces, this organism exhibits enhanced resistance to conventional chemical sanitizers, germicides and heat making control even more challenging.
My laboratory is interested in multiple aspects of biofilms:
The genetics of Listeriasp. biofilm growth.
The biological, physical and chemical aspects of bacterial adhesion, transfer and removal.
The microbial diversity and ecology of biofilms within food processing environments
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  • Publication
    Use of Micellar Delivery Systems to Enhance Curcumin’s Stability and Microbial Photoinactivation Capacity
    (2021-01-01) Ryu, Victor; Ruiz-Ramirez, Silvette; Chuesiang, Piyanan; McLandsborough, Lynne A; McClements, David Julian; Corradini, Maria G
    Microbial photoinactivation using ultraviolet (UV) or visible light can be enhanced by photosensitizers. This study assessed the efficacy of encapsulating a food-grade photosensitizer (curcumin) in surfactant micelles on its water dispersibility, chemical stability, and antimicrobial activity. Stock curcumin-surfactant solutions were prepared with Surfynol 465 (S465) or Tween 80 (T80) (5 mM sodium citrate buffer). The antimicrobial activity of curcumin-loaded surfactant solutions was determined by monitoring the inactivation of Escherichia coli O157: H7 and Listeria innocua after 5-min irradiation with UV-A light (λ = 365 nm). The solutions mixed with the bacterial suspensions contained 1 µM curcumin and each surfactant below, near, and above their critical micelle concentrations (CMCs). The addition of surfactants at any level to the curcumin solution enhanced its dispersibility, stability, and efficacy as a photosensitizer, thereby enhancing its antimicrobial activity. Gram-positive bacteria were more susceptible than Gram-negative bacteria when curcumin-loaded micelles were used against them. The photoinactivation efficacy of curcumin-surfactant solutions depended on the pH of the solution (low > high), surfactant type (S465 > T80), and the amount of surfactant present (below CMC ≥ near CMC > above CMC = unencapsulated curcumin). This result suggests that excessive partitioning of curcumin into micelles reduced its ability to interact with microbial cells. Synergistic antimicrobial activity was observed when S465 was present below or near the CMC with curcumin at pH 3.5, which could be attributed to a more effective interaction of the photosensitizer with the cell membranes as supported by the fluorescence lifetime micrographs. The use of a micelle-based delivery system facilitates adsorption and generation of reactive oxygen species in the immediate environment of the microbial cell, enhancing photoinactivation.