The antibacterial and anti-biofouling performance of biogenic silver nanoparticles by Lactobacillus fermentum

Abstract

Biofouling is a major challenge in the water industry and public health. Silver nanoparticles (AgNPs) have excellent antimicrobial properties and are considered to be a promising anti-biofouling agent. A modified method was used to produce small sized and well-dispersed biogenic silver nanoparticles with a mean size of ~6 nm (Bio-Ag0-6) using Lactobacillus fermentum. The morphology, size distribution, zeta potential and oxidation state of the silver were systematically characterized. Determination of minimal inhibitory and bactericidal concentration results revealed that biogenic silver Bio-Ag^0-6 can effectively suppress the growth of the test bacteria. Additionally, the inhibition effects of Bio-Ag^0-6 on biofilm formation and on established biofilms were evaluated using P. aeruginosa (ATCC 27853) as the model bacterium. The results from microtiter plates and confocal laser scanning microscopy demonstrated that Bio-Ag^0-6 not only exhibited excellent antibacterial performance but also could control biofilm formation and induce detachment of the bulk of P. aeruginosa biofilms leaving a small residual matrix.

Keywords:

• biogenic silver nanoparticles
• stability
• antibacterial
• antibiofilm
• biofouling

Acknowledgments

KSZ thanks the Royal Academy of Engineering, UK for the support received under the Research Exchange with China/India scheme. RWF thanks the Chinese Academy of Sciences for the award of a Distinguished Visiting Professor Fellowship. The authors gratefully acknowledge the financial support of the Xiamen Municipal Bureau of Science and Technology. The authors are also grateful to the reviewers for their helpful and insightful comments.