Exhaustive ecotoxicological evaluation of the product of malachite green biodegradation by Stenotrophomonas koreensis

Abstract

Stenotrophomonas koreensis effectively biodegrades malachite green, a mutagenic, carcinogenic, and teratogenic dye, raising the need to assess the safety of its degradation products before environmental release. This study addresses the gap in previous research by comprehensively evaluating the toxicity profile of malachite green degradation by S. koreensis. It incorporates a diverse range of organisms from terrestrial and aquatic ecosystems to assess the environmental impact of chemical introductions precisely. In-silico toxicological analysis was conducted using the online servers SwissADME, GUSAR, and vNN-ADMET, and ecotoxicological studies, following OECD guidelines. Aquatic toxicity was tested on cyanobacteria Anabaena flos-aquae, zooplankton Daphnia magna, aquatic macrophyte Lemna minor, and zebrafish Danio rerio. Terrestrial contamination risks were assessed with soil bacteria Bacillus subtilis, Bacillus pumilus, earthworm Eisenia fetida, important crop plants Triticum aestivum, Lens culinaris, and model organism Mus musculus. Genotoxicity was evaluated with Allium cepa root tip cells, and MTT assays were performed on HaCat cell line. Results indicate the degradation product's significantly reduced toxicity compared to malachite green. This study underscores the importance of thorough toxicity assessment in ensuring the safe disposal of dye degradation products into the environment.