• Journal of Ecology and Environment
• /
• 제40권2호
• /
• pp.120-124
• /
• 2016

Background: Although cetrimonium bromide is widely used for its bactericidal effects, the safety of cetrimonium bromide remains controversial. Therefore, the phytotoxicity of cetrimonium bromide was tested to evaluate its acute toxicity to plants and possible toxicity to other organisms and the ecosystem. Results: The germination rates of two test species, Lactuca sativa and Brassica campestris, were significantly decreased after cetrimonium bromide treatment. Furthermore, cetrimonium bromide treatment at over 1 mg/L concentration significantly affected root elongation immediately after germination. In pot experiments with semi-mature plants, significantly decreased shoot elongation and chlorophyll content were detected in both species following cetrimonium bromide treatment. Cetrimonium bromide treatment also significantly increased the antioxidant enzyme activities of plants. Conclusion: Our results show that cetrimonium bromide is phytotoxic, and since phytotoxicity testing can imply potential toxicity in the environment, further studies of the environmental toxicity of cetrimonium bromide should be performed.

• Journal of Microbiology and Biotechnology
• /
• 제31권3호
• /
• pp.439-446
• /
• 2021

Quercus infectoria (nutgall) has been reported to possess antimicrobial activities against a wide range of pathogens. Nevertheless, the biofilm removal effect of nutgall extract has not been widely investigated. In this study, we therefore evaluated the effect of nutgall extract in combination with cetrimonium bromide (CTAB) against preformed biofilm of Salmonella Typhimurium on polypropylene (PP) and stainless steel (SS) coupons in comparison with other sanitizers. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of nutgall extract and surfactants (CTAB and sodium dodecyl sulfate; SDS) were assessed. CTAB showed a more efficient antimicrobial activity than SDS and was selected to use in combination with nutgall extract for removing biofilm. To determine the biofilm removal efficacy, the PP and SS coupons were individually submerged in 2x MBC of nutgall extract (256 mg/ml) + 2x MBC of CTAB (2.5 mg/ml), nutgall extract alone (256 mg/ml), CTAB alone (2.5 mg/ml), distilled water, and 100 ppm sodium hypochlorite for 5, 15, and 30 min. The remaining sessile cells in biofilm were determined. Overall, the greatest biofilm removal efficacy was observed with nutgall extract + CTAB; the biofilm removal efficacy of sanitizers tended to increase with the exposure time. The SEM analysis demonstrated that S. Typhimurium biofilm on PP and SS coupons after exposure to nutgall extract + CTAB for 30 min displayed morphological alterations with wrinkles. This study suggests nutgall extract + CTAB may be an alternative to commonly used sanitizers to remove biofilm from food contact surfaces in the food industry and household.

• 한국분말재료학회지
• /
• 제29권3호
• /
• pp.207-212
• /
• 2022

Nanosized rutile titanium dioxide (TiO₂) is used in inorganic pigments and cosmetics because of its high whiteness and duality. The high quality of the white pigments depends on their surface coating technique via the solgel process. SiO₂ coatings are required to improve the dispersibility, UV-blocking, and whiteness of TiO₂. Tetraethyl orthosilicate (TEOS) is an important coating precursor owing to its ability to control various thicknesses and densities. In addition, we use Na₂SiO₃ (sodium silicate) as a precursor because of its low cost. Compared to TEOS, which controls the pH using a basic catalyst, Na₂SiO₃ controls the pH using an acid catalyst, giving a uniform coating. The coating thickness of TiO₂ is controlled using a surface modifier, cetrimonium bromide, which is used in various applications. The shape and thickness of the nanosized coating layer on TiO₂ are analyzed using transmission electron microscopy, and the SiO₂ nanoparticle behavior in terms of the before-and-after size distribution is measured using a particle size analyzer. The color measurements of the SiO₂ pigment are performed using UV-visible spectroscopy.