Pharmaceuticals suppress algal growth and microbial respiration and alter bacterial communities in stream biofilms

• Published in: Ecological applications 2013-04, Vol.23 (3), p.583-593
• Main Authors: Rosi-Marshall, Emma J, Kincaid, Dustin W, Bechtold, Heather A, Royer, Todd V, Rojas, Miguel, Kelly, John J
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Aquatic ecosystems; Bacteria; Bacteria - classification; Bacteria - drug effects; Biofilms; Biofilms - drug effects; Biological and medical sciences; caffeine; Chemical composition; Chlorophyll; ciprofloxacin; Communities; diphenhydramine; Drug interactions; Ecosystem; ecosystem function; Flavobacterium; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; Histamine H1 antagonists; Microbial ecology; Oxygen Consumption - drug effects; Pharmaceutical preparations; Pharmaceutical Preparations - chemistry; Pseudomonas; Respiration; Rivers; Surface water; Synecology; Various environments (extraatmospheric space, air, water); Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - pharmacology
• ISSN: 1051-0761; 1939-5582
• DOI: 10.1890/12-0491.1

Pharmaceutical and personal care products are ubiquitous in surface waters but their effects on aquatic biofilms and associated ecosystem properties are not well understood. We measured in situ responses of stream biofilms to six common pharmaceutical compounds (caffeine, cimetidine, ciprofloxacin, diphenhydramine, metformin, ranitidine, and a mixture of each) by deploying pharmaceutical-diffusing substrates in streams in Indiana, Maryland, and New York. Results were consistent across seasons and geographic locations. On average, algal biomass was suppressed by 22%, 4%, 22%, and 18% relative to controls by caffeine, ciprofloxacin, diphenhydramine, and the mixed treatment, respectively. Biofilm respiration was significantly suppressed by caffeine (53%), cimetidine (51%), ciprofloxacin (91%), diphenhydramine (63%), and the mixed treatment (40%). In autumn in New York, photosynthesis was also significantly suppressed by diphenhydramine (99%) and the mixed treatment (88%). Pyrosequencing of 16S rRNA genes was used to examine the effects of caffeine and diphenhydramine on biofilm bacterial community composition at the three sites. Relative to the controls, diphenhydramine exposure significantly altered bacterial community composition and resulted in significant relative increases in Pseudomonas sp. and decreases in Flavobacterium sp. in all three streams. These ubiquitous pharmaceuticals, alone or in combination, influenced stream biofilms, which could have consequences for higher trophic levels and important ecosystem processes.