Application of immobilized mycelium-based pellets for the removal of organochlorine compounds: a review

Abstract

Organochlorines have diverse structures and applications and are included in the list of persistent organic pollutants (POPs) due to their toxicity and environmental persistence. The reduced capacity of conventional wastewater treatment plants to remove these compounds encourages the development of cost-effective and efficient remediation approaches. Fungal biotechnology can contribute to the development of these technologies through their enzymatic machinery but faces several drawbacks related to the use of dispersed mycelium. In this sense, investigations concerning the degradation of organochlorines using immobilized fungi demonstrated an increase in contaminant removal efficiency compared with degradation by free cells. Despite this interest, the mechanisms of immobilized fungi have not been comprehensively reviewed. In this paper, recent advances of laboratory and field studies in organochlorine compounds removal by fungi are reviewed, focusing on the role of immobilization techniques. Firstly, the mechanisms of organochlorines bioconversion by fungi and the factors affecting enzyme activity are elucidated and discussed in detail. Then, the main targeted compounds, fungi, technics, and materials used for immobilization are discussed, as well as their advantages and limitations. Furthermore, critical points for future studies of fungi immobilization for organochlorine removal are proposed. HIGHLIGHTS Recent researches on fungal bioconversion of organochlorine compounds are introduced.; Strategies for enhancing enzymatic activity through immobilization are outlined.; Cost-effective and novel materials used for immobilization are listed.; Simultaneous cultivation of fungi and bacteria to form immobilized biomixtures is graphically described.;

Keywords

• bioconversion
• fungal immobilization
• novel materials
• organochlorine compounds