Use of rhamnolipid biosurfactant for membrane biofouling prevention and cleaning

Abstract

Rhamnolipids were evaluated as biofouling reducing agents in this study. The permeability of the bacterial outer membrane was increased by rhamnolipids while the growth rate of Pseudomonas aeruginosa was not affected. The surface hydrophobicity was increased through the release of lipopolysaccharides and extracellular polymeric substances from the outer cell membrane. Rhamnolipids were evaluated as agents for the prevention and cleaning of biofilms. A high degree of biofilm detachment was observed when the rhamnolipids were used as a cleaning agent. In addition, effective biofilm reduction occurred when rhamnolipids were applied to various species of Gram-negative bacteria isolated from seawater samples. Biofilm reduction using rhamnolipids was comparable to commercially available surfactants. In addition, 20% of the water flux was increased after rhamnolipid treatment (300 μg ml⁻¹, 6 h exposure time) in a dead-end filtration system. Rhamnolipids appear to have promise as biological agents for reducing membrane biofouling.

Keywords:

• rhamnolipid
• Pseudomonas aeruginosa
• biofouling reduction
• reverse osmosis membrane

Conflict of interest disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental material

The supplemental material for this paper is available online at http://dx.doi.org/10.1080/08927014.2015.1022724.

Additional information

Funding

This research was supported by a grant [13IFIP-C071144-01] from the operation and application of the management system for SeaHERO program products funded by the Ministry of Land, Transport, and Maritime Affairs of the government of Korea, and in part by the Basic Research in High-tech Industrial Technology Project through a grant provided by the Gwangju Institute of Science and Technology in 2014.