Survival and growth of saprotrophic and mycorrhizal fungi in recalcitrant amine, amide and ammonium containing media

Abstract

The elimination of hazardous compounds in chemical wastes can be a complex and technically demanding task. In the search for environmental-friendly technologies, fungal mediated remediation and removal procedures are of concern. In this study, we investigated whether there are fungal species that can survive and grow on solely amine-containing compounds. One compound containing a primary amine group; 2-diethylaminoethanol, one compound with a primary amide group; 2,6-dichlorobenzamide (BAM), and a third compound containing a quaternary ammonium group; N3-trimethyl(2-oxiranyl)methanaminium chloride, were selected. The choice of these compounds was motivated by their excessive use in large scale manufacturing of protein separation media (2-diethylaminoethanol and the quaternary amine). 2,6-dichlorobenzamide, the degradation product of the herbicide 2,6-dichlorobenzonitrile (dichlobenil), was chosen since it is an extremely recalcitrant compound. Utilising part of the large fungal diversity in Northern European forests, a screening study using 48 fungal isolates from 42 fungal species, including saprotrophic and mycorrhizal fungi, was performed to test for growth responses to the chosen compounds. The ericoid (ERM) mycorrhizal fungus Rhizoscyphus ericae showed the best overall growth on 2-diethylaminoethanol and BAM in the 1–20 g L-1 concentration range, with a 35-fold and 4.5-fold increase in biomass, respectively. For N3-trimethyl(2-oxiranyl)methanaminium chloride, the peak growth occurred at 1 g L-1. In a second experiment, including three of the most promising fungi (Laccaria laccata, Hygrophorus camarophyllus and Rhizoscyphus ericae) from the screening experiment, a simulated process water containing 1.9% (w/v) 2-diethylaminoethanol and 0.8% (w/v) N3-trimethyl(2-oxiranyl)methanaminium chloride was used. Laccaria laccata showed the best biomass increase (380%) relative to a control, while the accumulation for Rhizoscyphus ericae and Hygrophorus camarophyllus were 292% and 136% respectively, indicating that mycorrhizal fungi can use amine- and amide-containing substrates as nutrients. These results show the potential of certain fungal species to be used in alternative green wastewater treatment procedures.

Investigation of neomycin biodegradation conditions using ericoid mycorrhizal and white rot fungal species

“…Some of the experiments which were performed with T. versicolor and contained nutrient solution (NS) at different concentrations, were excluded for R. ericae . This was done mainly because this species had previously shown excellent capabilities to grow and survive on toxic nitrogen containing substances [ 20 ]. The flasks were then subjected to biodegradation experiments that lasted for 168 h. The flasks were covered with aluminum foil and agitated (50 rpm).…”

“…A fungal species which has been proven to be able to use recalcitrant nitrogen containing compounds as nutrients is the mushroom Rhizoscyphus ericae ( R. ericae ) [ 20 ]. It is an ericoid mycorrhizal symbiotic species which belongs to the phylum Ascomycota.…”

Investigation of neomycin biodegradation conditions using ericoid mycorrhizal and white rot fungal species

“…Some of the experiments which were performed with T. versicolor and contained nutrient solution (NS) at different concentrations, were excluded for R. ericae. This was done mainly because this species had previously shown excellent capabilities to grow and survive on toxic nitrogen containing substances (Stenholm et al 2021). The asks were then subjected to biodegradation experiments that lasted for 168 h. The asks were covered with aluminum foil and agitated (50 rpm).…”

“…A fungal species which has been proven to be able to use recalcitrant nitrogen containing compounds as nutrients is the mushroom Rhizoscyphus ericae (R. ericae) (Stenholm et al 2021). It is an ericoid mycorrhizal symbiotic species which belongs to the phylum Ascomycota.…”