Influence of membrane surface properties on the behavior of initial bacterial adhesion and biofilm development onto nanofiltration membranes

Abstract

In order to investigate biofouling problems, the fundamental behaviors of initial bacterial adhesion and biofilm development on four different nanofiltration (NF) membranes were evaluated using Pseudomonas aeruginosa PAO1 as a model bacterial strain. Initial cell adhesion was considerably higher on an aromatic polyamide-based NF membrane with a hydrophobic and rough surface, whereas cell aggregation on a polypiperazine-based NF membrane with a relatively hydrophilic and smooth surface was lower. Moreover, significant differences in the structural heterogeneity of the biofilms were observed among the four NF membranes. This study shows that the surface roughness and hydrophobicity of a membrane play an important role in determining initial cell adhesion, aggregation and favorable localization sites for colony formation. In addition, it was found that biofilm development was strongly influenced by the surface morphology of a membrane.

Keywords:

• nanofiltration
• bacterial adhesion
• biofilm
• biofouling
• surface roughness
• hydrophobicity

Acknowledgments

The authors gratefully acknowledge the financial support for this project provided by grants from the Korea Foundation for Advanced Studies (KFAS) for the International Scholar Exchange Fellowship (ISEF) program, 2008 and 2009 and the WCU (World Class University) program through the Korea Science and Engineering Foundation by the Ministry of Education, Science and Technology (400-2008-0230). The authors also express their appreciation to the DOW Chemical Company (USA) and the Woongjin Chemical Company (Korea) for kindly providing the NF membranes for this study.