Acetaminophen Concentrations Found in Recycled Wastewater alter Soil Microbial Community Structure and Functional Diversity

The practice of using recycled wastewater (RWW) (aka reclaimed water) has been adopted to address the growing demand for clean water and has been largely successful. However, chemicals of emerging concern (CECs) including pharmaceutical products such as acetaminophen (APAP) remain in the water even after additional cleaning. When recycled waste water is used to irrigate crops or landscapes these chemicals can then enter these and adjacent environments. APAP is one such contaminant and has the potential to disrupt the soil microbiome associated with agricultural crops. We evaluated this possibility using a greenhouse study to mimic agricultural field conditions, and applied treatments of APAP concentrations found within the ranges observed for RWW effluents. Using Illumina sequencing based approaches we observed that APAP was able to cause shifts in the microbial community and positively select for bacteria that are capable of metabolizing the breakdown products of APAP such as glycosides and carboxylic acids. Community-level physiological profiles of carbon metabolism were evaluated using Biolog EcoPlate as a proxy for community functions. The biolog plates indicated that the metabolism of amino acids, carbohydrates, carboxylic acids, phenolics, and polymers was significantly higher in the presence of APAP. Together our observations indicate that the soil microbial community and functions were altered by APAP and demonstrates the need to change current RWW policies to address the presence of these chemicals.