Paper Title
Neomycin Removal using Fungal Biotechnology

Problem statement: Recalcitrant compounds including antibiotics often remain in the effluents from wastewater treatment plants (WWTPs). The increased concentration levels of antibiotics like the aminoglycoside neomycin in wastewater streams leading to WWTPs thus constitute a breeding ground for antibiotic resistant bacteria. In this study, it was investigated whether it is possible to use fungal species to biodegrade this compound. Methods: The biodegradation of neomycin was investigated using the white rot fungus species Trametes versicolor (phylum Basidiomycota) and the ericoid mycorrhizal species Rhizoscyphusericae (phylum Ascomycota). The study was conducted in the presence (co-metabolism) and absence of external nutrients. The experimental design included the nutrients glucose and ammonium tartrate which were added at different concentration levels to determine their influence on the biodegradation degree. All experiments were conducted at pH 4.0 with the aim to suppress bacterial growth. Liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) was used for neomycin quantification purposes. The initial concentration of the aminoglycoside was 34 mg L-1 and was motivated by a large-scale application in which these concentration levels are relevant. Results: At selected co-metabolic conditions, approximately 70% of neomycin was removed by each species. Rhizoscyphusericae caused a removal of 60% in the absence of external nutrients. It was shown that this mycorrhizal species could use the antibiotic as growth substrate while the biodegradation using Trametes versicolor was directly correlated to the amounts of the external nutrients. Conclusion: This study indicates that there are species, belonging to different phyla that can be used in fungal biotechnology to biodegrade aminoglycosides like neomycin. Biodegradation at non-cometabolic conditions as was demonstrated by the use of Rhizoscyphusericae is of interest since the production costs in large scale applications will be reduced. Keywords – Neomycin, Biodegradation, LC-HRMS, Trametesversicolor, Rhizoscyphusericae