## 3 Results and Discussion  
### Preparation and Characterization of the IBCC-B Complexes  
Five CTS-MB materials with different particle sizes were prepared from a pulverous CTS substrate using a self-assembled device (Figure S1). With decreasing HV-PS voltage intensity values, the particle size of the prepared CTS-MBs increased continuously. As shown in Figure S3, all prepared CTS-MBs were uniform microspherical beads that were water-insoluble but well-compatible and well-dispersive in water. Among these CTS-MBs, the CTS-MB1 sample, which was prepared at the maximum working voltage (5.3 kV), had the smallest average particle size and largest average specific area compared to those of the other as-prepared materials; conversely, the CTS-MB5 sample prepared at 0 kV had the largest particle size and smallest average specific area. The engineered _P. putida_ cells with surface-displayed lacases were immobilized onto the CTS-MBs through immobilization reactions to construct dual-function biosorbent/biodegrading materials. To increase the immobilization efficiency, the as-prepared CTS-MB materials were initially modified with surface-grafted aldehyde groups, which allow _P. putida_ immobilization via covalent crosslinking to the CTS-MBs in addition to electrostatic and physical adsorption. An orthogonal test at four factors/five levels with regard to the effects of glutaraldehyde concentration (0.5%, 1.0%, 2.0%, 5.0% and 8.0%), reaction time (2, 4, 6, 8 and 12 h), temperature (4, 12, 16, 28 and 36 \({}^{\circ}\)C) and CTS-MB preparation (CTS-MB5 to CTS-MB1) was performed to optimize the immobilization reaction conditions based on the whole-complex lactose activity of each bacCTS-MB preparation (Table S2). Table S3 shows that the four factors exhibited an optimized effect on the CTS-MB-initiated immobilization of _P. putida_ MB285 in the following order: reaction time > temperature > glutaraldehyde concentration CTS-MB particle size. The optimized factors corresponded to the combination \"B3C3A5D5\" (Table S3), indicating that the optimized treatment conditions were as follows: an immobilization reaction time of 6 h, a temperature of 20 \({}^{\circ}\)C and a glutaraldehyde concentration of 8% with the smallest particle-sized CTS-MB1. Under the above optimized immobilization conditions, complexes bacCTS-MB1s were prepared by immobilizing _P. putida_ cells onto CTS-MB1s. For comparison, four other complexes (bacCTS-MB2s, -MB3s, -MB4s and -MB5s) were also prepared in parallel using the CTS-MB2, CTS-MB3, CTS-MB4 and CTS-MB5 matrices, respectively. Figure S4 shows that the bacCTS-MB1s exhibited the highest whole-complex increase enzyme activity as well as the highest immobilized count of _P. putida_ cells, --it is apparently attributable to the smallest specific surface area of CTS-MB1 by which more _P. putida_ MB285 cells were bound. Therefore, the bacCTS-MB1 complex was selected as the decolorization material for subsequent experiments. The immobilization profiles of the bacCTS-MB1 complex, aCTS-MB1s and free _P. putida_ MB285 cells were morphologically examined using SEM. The rugged and porous structures of the aCTS-MB1s (Figure 2A) were clearly observed and MB285 cells appeared in a naturally dispersed state (Figure 2B). However, the surface of the bacCTS-MB1 complex was covered by a large number of cells that formed clusters of cell aggregates (Figure 2C). These results indicated that during the formation of \"CTS-MB/_P. putida_ cells\" as an integral composite, the surface-grafted aldehyde groups and porous and ion-charged surfaces of CTS-MB1 caused the immobilization of _P. putida_ cells, which constitute an associative biomass. FT-IR spectroscopic analyses of free _P. putida_ MB285 cells, CTS-MB1s, aCTS-MB1s and bacCTS-MB1s were performed to verify the chemical groups involved in the binding of the CTS-MBs and _P. putida_ cells.