A review on superiority of mycelial pellets as bio-carriers: Structure, surface properties, and bioavailability

Abstract

As a novel carrier material, mycelial pellets have been used to enhance the removal efficiency of water pollutants, and have recently garnered significant research interest. However, the potential benefits of fungal pellets might have been undervalued. This article reviews the superiorities of mycelial pellets as biomass carriers, including regulable internal structure with a hollow and interconnected macropores and unique surface properties. These characteristics make them useful in water treatment and facilitate the adsorption of microorganisms or materials. As a biological entity, mycelial pellets can assist supporting microorganisms in degrading pollutants by direct utilization or enzyme secretion. Pellets can also be used as a bioreactor to synthesize and immobilize nanomaterials for environmental protection, and the microscopic materials can be realized in macroscopic applications by the pellets-based synthesis. Further, the ability of mycelial pellets to establish a symbiotic relationship with the supporting microbes is also reviewed, which maintains highly stable efficiency of the co-pellets in treating pollutants in water. Moreover, pellets have also been applied to accelerate the sludge granulation process and improve the removal performance and stability of granular sludge. Problems existing in intensive research areas using mycelial pellets as bio-carriers and the challenges faced in using mycelial pellets in largescale wastewater treatment are also presented.