Microbial bioremediation of persistent organic pollutants in plant tissues provides crop growth promoting liquid fertilizer

Constructed wetlands are used to clean domestic wastewater via phytoremediation, commonly involving the use of reeds. The process results in the production of large amounts of polluted plant tissues, which are then considered unusable waste products. In this study, the reusability of reeds and nettle-polluted tissues is investigated. Fermenting contaminated plant tissues to produce liquid fertilizer is a sustainable means to remove 87-95% of persistent organic pollutants. A multiomics approach combining metabolomics and amplicon metagenomics is used to analyze the mechanisms that occur during fertilizer production from polluted plant tissues and identify the microbes that are likely key for this transformation. A consortium of bacteria and fungi with cellulolytic activity is identified. In addition, the obtained liquid fertilizer positively impacts plant growth in the presence of pathogens and therefore exhibits potential application in farming. This approach may be a simple, commercially attractive solution for the management of contaminated plant tissues originating from constructed wetlands, which are currently considered problematic, useless waste products.