A microbe-immobilized support that improves the ability of bacteria to decompose organic pollutants by utilizing the organic inclusion effect of cyclodextrin (CyD) has been developed. Spherical hydrogels (ENTG-co-PSβCyD) were prepared by photocopolymerization of the polyethylene glycol macromonomer, ENTG, and the polysubstituted photocross-linkable β-CyD macromonomer PSβCyD. Then, the optimum composition ratio for use of this hydrogel as a microbe-immobilized support was determined, as were the phenol (PhOH)-removing abilities of PhOH-decomposing bacteria immobilized on this hydrogel. PhOH-degrading bacteria were immobilized on the spherical ENTG-co-PSβCyD hydrogel to obtain a microbe-immobilized hydrogel. The best microbe-immobilized support was obtained by using a spherical hydrogel with a PSβCyD content of approximately 28 μmol g−1, and this resulted in a PhOH-removal rate of 0.76 mg (L h hydrogel g)−1. This removal rate was 1.7 times faster, and the amount of free bacteria in the assay medium was 3.6 times lower than the corresponding data obtained using a microbe-immobilized hydrogel without PSβCyD. The spherical ENTG-co-PSβCyD hydrogel had a diameter of 2.9 mm, a moisture content of 63 wt%, a specific gravity of 1.16 g cm−3 and a Young’s modulus of 8.1 MPa. These results suggested that more efficient industrial wastewater treatment technologies must be developed.
Yamasaki, H., Nagasawa, Yy. & Fukunaga, K. Preparation of photocrosslinked spherical hydrogels bearing β-cyclodextrin and application in immobilizing microbes to decompose organic pollutants. Polym J (2022). https://doi.org/10.1038/s41428-022-00633-z