Biodegradation of bisphenols with immobilized laccase or tyrosinase on polyacrylonitrile beads

Abstract

The biodegradation of waters polluted by some bisphenols, endowed with endocrine activity, has been studied by means of laccase or tyrosinase immobilized on polyacrylonitrile (PAN) beads. Bisphenol A (BPA), Bisphenol B (BPB), Bisphenol F (BPF) and Tetrachlorobisphenol A (TCBPA) have been used. The laccase-PAN beads system has been characterized as a function of pH, temperature and substrate concentration. The biochemical parameters so obtained have been compared with those of the free enzyme to evidence the modification induced by the immobilization process. Once characterized, the laccase-PAN beads have been employed in a fluidized bed reactor to determine for each of the four bisphenols the degradation rate constant (k); the τ(50), i.e., the time to obtain the 50% of degradation, and the removal efficiency (RE(90)) after 90 min of enzyme treatment. The same parameters have been measured for each of the four pollutants with the same fluidized bed bioreactor loaded with tyrosinase-PAN beads. The internal comparison, i.e., in each of the two catalytic systems, has shown that both enzymes exhibit a removal efficiency in the following order BPF>BPA>BPB>TCBPA. The external comparison, i.e., the comparison between the two catalytic system, has shown that the catalytic power of laccase were higher than that of tyrosinase. The operational stability of both catalytic systems resulted excellent, since they maintained more than 80% of the initial activity after 30 days of work.

Laccase biosensor based on screen-printed electrode modified with thionine–carbon black nanocomposite, for Bisphenol A detection

“…As can be seen from value is similar to K m biochemical one reported in [50] and obtained from experiment with BPA and free laccase.…”

Covalently Immobilized Laccase for Decolourization of Glucose-Glycine Maillard Products as Colourant of Distillery Wastewater

“…2b). The results are in agreement with literature reporting temperature tolerance of immobilized enzyme in contrast to its soluble form [28][29][30]. Improvement in thermal stability upon immobilization is possibly due to a stable three-dimensional enzyme structure created by strong linkages between the oxide groups of APTES on the support and amino groups of the enzyme.…”

Understanding the factors controlling the removal of trace organic contaminants by white-rot fungi and their lignin modifying enzymes: A critical review

“…Tetrachlorobisphenol, which is a phenolic compound (containing -OH, a strong EDG), has been reported to be well degraded despite having -Cl groups (strong EWG and toxic) on the aromatic ring (Nicolucci et al, 2011). The antibacterial agent triclosan has been recently reported to be a suspected EDC.…”