Effect of silver oxide nanoparticles on a bacterial consortium isolated from the sediment of the Gulf of Mexico in removing carbon and nitrogen

摘要

Nanoparticle (NP) use in engineering, medicine, cosmetics, personal care products, and manufacturing is becoming more common resulting in a significant increase in accumulation in biological systems and have been shown to have disruptive and antimicrobial effects. Nanoparticle accumulation will disrupt the natural biogeochemical cycles such as carbon and nitrogen cycles by inhibiting microbes that participate in these cycles. The purpose of this study was to determine the effect of silver oxide nanoparticles on carbon and nitrogen cycles in the sediment bacteria isolated from the Gulf of Mexico of the coast of the state of Louisiana in the USA. A bacterial consortium developed from the coastal Louisiana was exposed to various concentrations of silver oxide nanoparticles. The results showed that the silver oxide NP at concentrations 4 mg/L or above were lethal to the bacteria, and bacterial growth was inhibited resulting in significant loss of carbon and nitrogen removal activities of the bacterial consortium. The lethal concentration 50 (LC_(50)) of silver oxide NP for the coastal bacteria was found to be 3.07 mg/L. The bacterial consortium was stressed at higher doses above 2 mg/L of NP leading to excess production of extracellular polymeric substances.