Mycoremediation of Flotation Tailings with Agaricus bisporus

Can the concentration of elements in wild-growing mushrooms be deduced from the taxonomic rank?

The mineral composition of wild-growing mushroom species is influenced by various environmental factors, particularly the chemical properties of the soil/substrate. We hypothesised that element uptake might also correlate with taxonomic classification, potentially allowing us to predict contamination levels based on mushrooms within the same taxonomic rank. This study compared the mineral composition (Ag, As, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se, and Zn) of 16 saprotrophic mushroom species from 11 genera across 4 families and 2 orders. Among these were 13 edible and 3 inedible mushrooms, all collected from natural, wild stands in a forest in central-western Poland between 2017 and 2020. Phallus impudicus exhibited the highest mean content of Ba (together with Phallus hadriani) (6.63 and 8.61 mg kg-1, respectively), Ca (with Paralepista gilva and Stropharia rugosoannulata) (803, 735 and 768 mg kg-1, respectively), Cd (with Lycoperdon perlatum) (3.59 and 3.12 mg kg-1, respectively), Co (0.635 mg kg-1), and Fe (with P. hadriani and S. rugosoannulata) (476, 427 and 477 mg kg-1, respectively), while Macrolepiota mastoidea showed the highest content of Ag (1.96 mg kg-1), As (with Coprinus comatus) (1.56 and 1.62 mg kg-1, respectively) and Cu (with Macrolepiota procera and Chlorophyllum rhacodes) (192, 175 and 180 mg kg-1, respectively). Comparing the content of the analysed elements in the genera represented by at least two species, a similarity was observed, the same as the mean concentration in soil under these species. Soil characteristics could be a superior factor that overshadows the impact of the mushroom genus on the elements accumulation, obscuring its role as a determinant in this process. The results are not definitive evidence that belonging to a particular taxonomic rank is a prerequisite condition affecting the accumulation of all elements. A closer focus on this issue is needed.

Preface to the Special Issue 'Heavy Metals in Mushrooms'

Population growth, intensive industrialization and urbanization have led to environmental pollution, especially soil and water pollution [...].

An Approach to Evaluate Pb Tolerance and Its Removal Mechanisms by Pleurotus opuntiae

Widespread lead (Pb) contamination prompts various environmental problems and accounts for about 1% of the global disease burden. Thus, it has necessitated the demand for eco-friendly clean-up approaches. Fungi provide a novel and highly promising approach for the remediation of Pb-containing wastewater. The current study examined the mycoremediation capability of a white rot fungus, P. opuntiae, that showed effective tolerance to increasing concentrations of Pb up to 200 mg L−1, evidenced by the Tolerance Index (TI) of 0.76. In an aqueous medium, the highest removal rate (99.08%) was recorded at 200 mg L−1 whereas intracellular bioaccumulation also contributed to the uptake of Pb in significant amounts with a maximum of 24.59 mg g−1. SEM was performed to characterize the mycelium, suggesting changes in the surface morphology after exposure to high Pb concentrations. LIBS indicated a gradual change in the intensity of some elements after exposure to Pb stress. FTIR spectra displayed many functional groups including amides, sulfhydryl, carboxyl, and hydroxyl groups on the cell walls that led to binding sites for Pb and indicated the involvement of these groups in biosorption. XRD analysis unveiled a mechanism of biotransformation by forming a mineral complex as PbS from Pb ion. Further, Pb fostered the level of proline and MDA at a maximum relative to the control, and their concentration reached 1.07 µmol g−1 and 8.77 nmol g−1, respectively. High Pb concentration results in oxidative damage by increasing the production of ROS. Therefore, the antioxidant enzyme system provides a central role in the elimination of active oxygen. The enzymes, namely SOD, POD, CAT, and GSH, served as most responsive to clear away ROS and lower the stress. The results of this study suggested that the presence of Pb caused no visible adverse symptoms in P. opuntiae. Moreover, biosorption and bioaccumulation are two essential approaches involved in Pb removal by P. opuntiae and are established as worthwhile agents for the remediation of Pb from the environment.

Internet of Things (IoT)-Based Environmental Monitoring and Control System for Home-Based Mushroom Cultivation

The control and monitoring of the environmental conditions in mushroom cultivation has been a challenge in the mushroom industry. Currently, research has been conducted to implement successful remote environmental monitoring, or, in some cases, remote environmental control, yet there is not yet a combination of both these systems providing live stream images or video. As a result, this research aimed to design and develop an Internet of things (IoT)-based environmental control and monitoring system for mushroom cultivation, whereby the growth conditions of the mushrooms, such as temperature, humidity, light intensity, and soil moisture level, are remotely monitored and controlled through a mobile and web application. Users would be able to visualize the growth of the mushroom remotely by video and images through the Internet. The respective sensors are implemented into the mushroom cultivation process and connected to the NodeMCU microcontroller, which collects and transfers the data to the cloud server, enabling remote access at any time through the end device with internet connection. The control algorithm regulates the equipment within the cultivational chamber autonomously, based on feedback from the sensors, in order to retain the optimum environment for the cultivation of mushrooms. The sensors were tested and compared with manual readings to ensure their accuracy. The implementation of IoT toward mushroom cultivation would greatly contribute to the advancement of the current mushroom industry which still applies the traditional cultivation approach.