• Agathos, Spiros
• Junghanns, Charles

Abstract

Rapid economic development in many regions of the globe has contributed to intensification of the contamination in our environment. Emerging pollutants including endocrine disruptors, pharmaceuticals and personal care products are persistent and recalcitrant to microbial attack.The ligninolytic system of white-rot fungi (WRF) consisting, among others, of laccase (E.C. 1.10.3.2) and peroxidases such as Mn peroxidase (E.C. 1.11.1.13) and lignin peroxidase (E.C. 1.11.1.14) is involved in the degradation of various xenobiotic compounds such as the above emerging contaminants. We have been investigating the biocatalytic elimination of established or suspected xenoestrogens including nonylphenol (NP), bisphenol A (BPA) and triclosan (TCS) using laccases from Coriolopsis polyzona, Lentinus critinus or Ganoderma japonicum. The enzymatic treatment produces high MW metabolites of NP, BPA and TCS (from dimers up to pentamers) which are devoid of hormone-like activity. A sequence of optimization techniques has enabled the improvement of the effluent treatment process using soluble laccase. To improve the effectiveness and re-use of the enzyme, we implemented it under solid and retainable form in appropriate bioreactors. When used in a conventional packed-bed reactor or in a novel perfusion basket reactor, support-immobilized or cross-linked insolubilized laccase was able to eliminate BPA from aqueous solutions under different operational conditions. These included several consecutive treatment cycles and even continuous processing with sustained removal performance. In addition to a critical appraisal of these developments, current and emerging biotechnological applications of fungal enzymes will highlight our research results, while the remaining challenges in mycoremediation will be addressed.

Topics

• impedance spectroscopy
• compound
• lignin