The concept of continuous utilization of laccase CLEAs

Cabana, Hubert [UCL] jones, Peter Agathos, Spiros N. [UCL]

Cross-linked enzyme aggregates (CLEAs) are an attractive alternative to immobilized enzymes on solid supports. The insolubilization of laccase through a simple cross-linking technique produces a particulate biocatalyst with high activity per unit volume. Cabana, Jones, and Agathos present an innovative perfusion basket reactor (BR) for the continuous use of laccase CLEAs. Made of a stainless steel filtration module, the bioreactor is filled with CLEAs and continuously agitated by a low-shear marine propeller. The optimal conditions of agitation — in terms of apparent laccase activity and stability — were determined. To demon- strate the concept, this bioreactor was used for the con- tinuous elimination of the endocrine disrupting chemicals (EDCs) nonylphenol, bisphenol A and triclosan, which are widely occurring water micropollutants. The authors also developed a simple kinetic model to predict the transforma- tion of these EDCs in the BR. This work takes us one step closer to the use of CLEAs in industrial and environmental biotechnology applications.