Production of Magnetically Controlled Biosorbents Based on Fungi Pleurotus ostreatus

Abstract

Background. Biogenic magnetic nanoparticles (BMN) have been found in representatives of all three superkingdoms of living organisms: bacteria, archaea and eukaryotes (including fungi). At the same time, it was established that the mechanism of biomineralization of BMN is unique for all living organisms. The search for sorbents of biological origin has become one of promising ways of addressing the problem of environmental pollution by heavy metals. Heavy metals are elements of transport emissions and many factories in various industries. These metals getting into the human body cause significant disruption of metabolism and vital functions of the body. Many macromycetes are known to be natural sorbents for heavy metal ions. Laboratory tests use a method of filtering spent sorbent through a paper filter, which is long enough and inefficient. Therefore, it is important to find a more effective way of removing biosorbent from the solution. Such a cheap and efficient method is high-speed magnetic gradient separation.

Objective. The aim of the paper is to obtain a magnetically controlled biosorbent based on a fungus Pleurotus ostreatus, to determine the fraction of the magnetically controlled phase of the fungus biomass when added to the substrate of the magnetic fluid, and to investigate the efficiency of extraction of Fe³⁺ ions by the fungus biomass of the fungus Pleurotus ostreatus.

Methods. The standard method of cultivation of the fungus Pleurotus ostreatus, the method of high-grade magnetic separation and the method of biosorption of ferric ions were used.

Results. The process of biosorption of ferric ions by a Pleurotus ostreatus grown on substrates with the addition of magnetic fluids of different concentrations was carried out. It is shown that the dry biosorbent based on the biomass of the Pleurotus ostreatus has a high sorption capacity with respect to Fe³⁺ ions since the efficiency of their extraction for 30 minutes of sorption in the samples grown on the substrate with the addition of magnetite is more than 95%. It is proved that when using biomass of ordinary fungus grown on a magnetic fluid, complete saturation occurs 6 times faster (for 5 minutes), compared to 30 min for biosorbent based on biomass of mushroom grown without magnetic fluid.

Conclusions. Addition of magnetite (concentration 0.1 and 1 mg/ml) to the substrate in the cultivation of fungi Pleurotus ostreatus significantly increases the efficiency of the sorbent. When using the fungus biomass of Pleurotus ostreatus without adding magnetite for 5 minutes, the efficiency of extraction of iron ions is 70%, for 30 min – 80%. When used to grow the magnetic fluid at a concentration of 0.1 mg/ml and 1 mg/ml for almost 5 minutes, almost complete removal of heavy metal ions occurs.