Polyethylenimine Increases Antibacterial Efficiency of Chlorophyllin

Abstract

Polyethylenimines (PEIs), a group of polycationic molecules, are known to impair the outer membrane of Gram-negative bacteria and exhibit antimicrobial activity. The outer membrane of Gram-negative strains hinders the uptake of photosensitizer chlorophyllin. In this study, we report chlorophyllin and branched PEI combinations’ activity against Escherichia coli strains DH5α and RB791, Salmonella enterica sv. Typhimurium LT2, and Bacillus subtilis 168. The minimal bactericidal concentration (MBC) was determined by plating cells treated with different concentrations of PEI and chlorophyllin on agar and monitoring their growth after 24 h. All tested combinations of PEI and chlorophyllin were lethal for S. enterica after 240 min of incubation in light, whereas PEI alone (<100 µg mL−1) was ineffective. In the darkness, complete inhibition was noted with a combination of ≥2.5 µg mL−1 chlorophyllin and 50 µg mL−1 PEI. If applied alone, PEI alone of ≥800 µg mL−1 of PEI was required to completely inactivate E. coli DH5α cells in light, whereas with ≥5 µg mL−1 chlorophyllin, only ≥100 µg mL−1 PEI was needed. No effect was detected in darkness with PEI alone. However, 1600 µg mL−1 PEI in combination with 2.5 µg mL−1 resulted in complete inactivation after 4 h dark incubation. PEI alone did not inhibit E. coli strain RB791, while cells were inactivated when treated with 10 µg mL−1 chlorophyllin in combination with ≥100 µg mL−1 (in light) or ≥800 µg mL−1 PEI (in darkness). Under illumination, B. subtilis was inactivated at all tested concentrations. In the darkness, 1 µg mL−1 chlorophyllin and 12.5 µg mL−1 PEI were lethal for B. subtilis. Overall, PEI can be used as an antimicrobial agent or potentiating agent for ameliorating the antimicrobial activity of chlorophyllin.

Cationic cellulose filter papers modified with ZnO/Ag/GO nanocomposite as point of use gravity-driven filters for bacterial removal from water

“…Their activity heavily depends on their structure, such as their molecular weight, type of functional groups, and form (linear or branched) 41 , 43 , 44 . Moreover, the combination of those cationic polymers with other antibacterial agents has led to the synergistic improvements in activity 45 . The lowest limit for efficient bacterial filtration ability is more than 99% (2-log reduction), showing the effectiveness of using three sheets of PDA/PEI modified papers.…”

Short-Term Stability of Electrochemical Properties of Layer-by-Layer Coated Heterogeneous Ion Exchange Membranes

“…Polyethylenimine is frequently used as a polymer carrier [ 44 ] and basis for loading of nanoparticles [ 45 ] or coating for medical applications [ 46 ]. However, its use in biomedical application is shaped by the cyto-staticity [ 47 ] or cytotoxicity of amine groups which simultaneously makes it non-biocompatible [ 48 ] and useful as antimicrobial and anticancer agent [ 49 , 50 ]. Both of these polyamines are popular components of layered coatings aimed to increase monovalent selectivity [ 14 , 51 , 52 , 53 ].…”

New trends in the development of photodynamic inactivation against planktonic microorganisms and their biofilms in food system

“…The chlorophyllin belongs to porphyrin compounds, which is insoluble in water, but it is often used in its form of water‐soluble derivatives such as sodium chlorophyllin, sodium copper chlorophyllin, and sodium magnesium chlorophyllin (Akif et al., 2022). These water‐soluble derivatives exhibit an improved photosensitivity and are proven to be safe in the food industry.…”