Assimilable organic carbon (AOC) in reverse osmosis (RO) feed water has been assumed to be the key determinant for microorganism growth leading to membrane fouling and limiting the use of this membrane technology. The lux reporter system developed in this study can be used as a membrane fouling indicator to estimate fouling potential of RO pre-treated feed water. The construction of bioluminescent reporter plasmids was done by integrating luxAB genes from Vibrio fischeri MJ1 downstream of a

more »

... ng promoter (lacIQ) into high copy number plasmids pUC19. To investigate the use of the lux reporter for detection of AOC, the pUC19-luxAB system was introduced into a common marine bacterium, Vibrio cholerae A1552 by electroporation. The results showed that luxAB genes were successfully expressed in V. cholerae A1552 with the bioluminescence reading of 3.3 x 10 4 relative light unit (RLU), which was 3000-fold greater than the background signal. The linear curve constructed by A1552 (pUC19-luxAB) with a coefficient (R 2 ) of 0.9761 showed that there was a strong correlation between bioluminescent intensity and glucose concentrations in a range of 0 -100 µg C L -1 . The detection limit of this assay was 20 µg C L -1 .