Mechanism of enhanced antibacterial activity of ultra-fine ZnO in phosphate buffer solution with various organic acids. (November 2016)

• Record Type: Journal Article
• Authors: Yang, Lin; Kuang, Huijuan; Liu, Yingxia; Xu, Hengyi; Aguilar, Zoraida P.; Xiong, Yonghua; Wei, Hua
• Is Part Of: Environmental pollution. Volume 218(2016)
• Page Start: 863
• Page End: 869
• Publication Date: 2016-11
• Subjects: Ultra-fine-ZnO -- Antibacterial activity -- Bacillus cereus -- Escherichia coli -- Released Zn2+; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2016.08.015
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Ultra-fine-ZnO showed low toxicity in complex water matrix containing multiple components such as PBS buffer and the toxic mechanism of ultra-fine-ZnO has not been clearly elucidated. In present study, enhanced antibacterial activity of 200 nm diameter ultra-fine-ZnO in PBS buffer against Bacillus cereus and Escherichia coli were observed in the presence of several organic acids in comparison with ultra-fine-ZnO in PBS buffer alone. These findings indicated that the toxic effects of the ultra-fine-ZnO was dependent on the concentration of released Zn 2+ which was affected by organic acids. The production of reactive oxygen species (ROS) did not responsible to the toxic mechanism of ultra-fine-ZnO which was tested using the antioxidant N -Acetylcysteine (NAC). Indeed, ultra-fine-ZnO induced bacteria cell membrane leakages and cell morphology damages that eventually led to cell death, which were confirmed using propidium monoazide (PMA) in combination with PCR and scanning electron microscopy (SEM). All data gathered herein suggested that released Zn 2+ played a major role in the microbial toxicity of ultra-fine-ZnO. Graphical abstract: Highlights: Ultra-fine-ZnO showed strong antibacterial effect in PBS with organic acids. Several organic acids enhanced the concentration of Zn 2+ in the PBS. Released Zn 2+ played a major role in the toxic mechanism of ultra-fine-ZnO. Ultra-fine-ZnO induced bacteria cell leakages and morphology damages. Abstract : Organic acids enhanced the antibacterial activity of ultra-fine ZnO in PBS due to the release of Zn 2+ which played a major role in its microbial toxicity mechanism.