Immunomagnetic separation of scum-forming bacteria using polyclonal antibody that recognizes mycolic acids

Mycolic acid-containing bacteria (mycolata) are thought to be involved in scum formation in aeration basins of activated sludge plants due to their ability to produce biosurfactants and their cell surface hydrophobicity. To isolate these bacteria, immunomagnetic separation (IMS) using an anti-mycolic acid polyclonal antibody was investigated. IMS that targeted Gordonia amarae SC1 exhibited a 100% recovery at 5x10(3) CFU ml(-1). At cell concentration of 7.8x10(6) CFU ml(-1), the recovery was lowered, but 80% of cells were still captured. Effect of bead concentrations on the recovery of SC1 at 10(6) CFU ml(-1) was examined. The results showed that addition of more than 6-7x10(6) beads for 1x10(6) CFU reached a maximum recovery (83%). Furthermore, the IMS procedure optimized with SC1 cells was tested with another mycolata. The results suggested that variation of the recovery for each mycolata is dependent on the specificity of the polyclonal antibody and that mycolata which are recognized by the antibody can be recovered by this procedure.