Nisin-activated hydrophobic and hydrophilic surfaces: assessment of peptide adsorption and antibacterial activity against some food pathogens

Abstract

An effective antimicrobial packaging or food contact surface should be able to kill or inhibit micro-organisms that cause food-borne illnesses. Setting up such systems, by nisin adsorption on hydrophilic and hydrophobic surfaces, is still a matter of debate. For this purpose, nisin was adsorbed on two types of low-density polyethylene: the hydrophobic native film and the hydrophilic acrylic acid-treated surface. The antibacterial activity was compared for those two films and it was highly dependent on the nature of the surface and the nisin-adsorbed amount. The hydrophilic surfaces presented higher antibacterial activity and higher amount of nisin than the hydrophobic surfaces. The effectiveness of the activated surfaces was assessed against Listeria innocua and the food pathogens Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. S. aureus was more sensitive than the three other test bacteria toward both nisin-functionalized films. Simulation tests to mimic refrigerated temperature showed that the films were effective at 20 and 4 °C with no significant difference between the two temperatures after 30 min of exposure to culture media.

Incorporation of antimicrobial peptides on electrospun nanofibres for biomedical applications

“…48,49 In addition to electrostatic forces, the adsorption mechanisms between peptides and the backbone of PAA-PVA can be mediated by non-electrostatic interactions such as hydrogen bonding and dipole-dipole interactions with the polar groups in. 44,50,51 For both peptides the amount loaded was considerably higher at neutral (pH 7) than at basic conditions (pH 10), and higher for lysozyme than for nisin. These results can be interpreted as a consequence of a decrease in the net charge of peptides, which is positive if pH is lower than the isoelectric point and negative if it is higher and supports the preferential role of electrostatic interactions in the adsorption of AMP on PAA-PVA bres.…”

“…Qualitative and quantitative assessments were employed for the bacterial inhibition studies using agar diffusion and liquid incubation methods, respectively. 44 For agar diffusion tests, neat and functionalized dressings ($1 cm 2 ) were placed onto the surface of so agar plates previously inoculated with 0.6 mL S. aureus suspension with approximately 10 6 Colony Forming Units (CFU) per mL. Plates were incubated at 37 C for 14 days.…”

Adsorption of Nisin on Montmorillonite: A Concentration Strategy

“…Thus, different techniques which avoid classic multi-step chromatographic methods (Garsa et al 2014), like liquid-liquid extraction with organic solvents (Taylor et al 2007) or aqueous two-phase micellar systems (Jozala et al 2008), adsorption on hydrophobic and hydrophilic surfaces (Karam et al 2013), among others, were proposed. The immobilization of nisin on hydrophilic supports results interesting due to the amphiphilic nature of the peptide, which allows the adsorption of the peptide and retention of the antibacterial activity on the adsorbed state ( Daeschel et al 1992;Karam et al 2013). In this sense, the adsorption of nisin on montmorillonite is feasible since the protonation of amino residues in nisin molecule could favour electrostatic interactions with the negatively-charged surfaces of the clay mineral.…”

Food Safety through Natural Antimicrobials

“…It is considered as a Generally Recognized as Safe (GRAS) food preservative, and once it is absorbed onto surfaces it inhibits the growth of Listeria spp. and prevents the formation of biofilms [211][212][213][214][215][216]. Pediocins also inhibit the growth of L. monocytogenes and they are used in salads and salad dressings, cream, cheese and meats [216][217][218][219][220][221][222][223][224][225].…”