# Mycoremediation of PCBs by _Pleurotus ostreatus_: Possibilities and Prospects
## 5 _P. ostreatus_-Based Degradation of PCBs: Future Prospects  
As surmised in an earlier section, _P. ostreatus_ does have an unequivocal edge over other WRFs when it comes to bioremediation of PCBs. The future prospects of this fungus towards the removal of PCBs are thus highly promising. In recent times, bioremediation processes more and more often employ immobilization methods. Immobilization is defined as limiting the mobility of the microbial cells or their enzymes with a simultaneous preservation of their viability and catalytic functions [68; 69; 70; 71; 72]. There are five main techniques of immobilization: adsorption, binding on a surface (electrostatic or covalent), flocculation (natural or artificial), entrapment, and encapsulation. This review identifies that no incorporation of such upgraded techniques available for preparing fungal masses for bioremediation protocols has been implanted for _P. ostreatus_-based degradation of PCBs. Since the fact that _P. ostreatus_ can deliver much when it comes to PCBs remains unquestioned, it is now necessary that the biotechnological innovations are put to use for preparing this fungal biomass in the most efficient form. Most of the studies demonstrated on removal of PCBs using _P. ostreatus_ merely use the hyphae as it is. More research on how the fungi can best be prepared for maximizing the PCB recovery is the need of the hour.  
Figure 1: Schematic representation of the overview of bioremediation of polychlorinated biphenyls (PCBs) by _P. ostreatus_.  
Immobilization of hyphae in columns as micro or nanobeads will enhance the surface-active area; further, incorporation of hyphae in polymer matrices as well as nanomaterials could significantly enhance the bioremediation aspects of _P. ostreatus_ with respect to PCBs. [PERSON] et al. recently presented an exhaustive list of options of natural carriers for bioremediation ranging from naturally occurring materials to nanopolymers [73]. With such options and advancements available, we strongly suggest some amount of improvisation into the routines to harness the best that this fungus has to offer toward bioremediation of PCBs. The SMS of _P. ostreatus_ as explained in the previous section, which showed extensive PAH removal activity, is an area worth developing on with respect to PCBs. The SMS of _P. ostreatus_ has been limited to a single study [64] for PCB degradation. This study showed that the differences between PCB degradation by substrate and SMS of _P. ostreatus_ were very weak; hence, they suggested that it is possible to use SMS for the decontamination of PCB polluted soil. The Council Directive 1999/31/EC declared that each European Union country should reduce the amount of organic refuse by 50% by 2050 [74]. Poland, Korea, and China are the biggest producers of _P. ostreatus_, annually generating over a thousand tons of spent mushroom substrate. The proper channelizing of the SMS of this mushroom towards PCB remediation could solve the problem of disposal of this mushroom's refuse. Additionally, the use of the SMS allows for standardization of the exact dose requirement with respect to specific PCB concentrations or environmental conditions. Furthermore, SMS not only decontaminates the soil but is also a high value fertilizer. Further, every technology projection is weighed for its versatility and usefulness based on its cost effectiveness, with the SMS of this fungi showing degradation ability on par with the substrate/mycelium. In this direction, we are certainly talking of a major advantage in terms of cost-effectiveness while using the spent mushroom waste and not the mushroom itself. There is a high prospect that this venture could be highly prospective and cost-effective.