Differential Sensitivity of Wetland-Derived Nitrogen Cycling Microorganisms to Copper Nanoparticles

Abstract

Metallic nanoparticles (NPs), the most abundant nanomaterials in consumer and industrial products, are the most probable class to enter and potentially affect the environment. In this study, wetland-derived microcosms were incubated with copper nanoparticles (Cu-NP) and ionic CuCl 2 to investigate acute (10 days) and chronic (100 days) exposures to nitrogen cycling microorganisms. Gene abundance and expression changes were monitored using the GeoChip 5.0 high throughput functional gene microarray and metatranscriptomic sequencing (RNA-seq), respectively. After 10 days, the Cu-NP impacted microbial communities experienced structural shifts within microorganisms associated with dissimilatory nitrogen reduction accompanied by lower nitrate removal as compared to the unexposed controls. By day 100, these differences were largely resolved and nitrate removal was similar to the unexposed control. Furthermore, the Cu-NP exposed microcosms tolerated copper and were more resilient and adaptive than the unexposed controls based on the abundance of copper oxidase (cueO), copper efflux (cusC), and bacterial adaptive response (opuE, soxS, desR, baeS) genes. These findings suggest that sudden influxes of Cu-NPs into wetland systems may impair nitrogen removal initially, but long-term microbial shifts and functional redundancy would promote the net flux of total nitrogen out of the wetlands.

Silver nanoparticles alter the bacterial assembly and antibiotic resistome in biofilm during colonization

“…A similar rebound phenomenon was also reported in previous studies, in which NPs exposure altered the structure of the microbial community during a short time, but after relatively longer exposure, the bacterial communities showed resilient recovery. 1,50 One reason why microbiota could recover from exposure to AgNPs may be because the microorganisms can adapt to environmental changes quickly. 50,51 In addition, the EPS, which can act as a barrier to keep AgNPs from reaching bacteria, 48 is increasingly secreted during biofilm development.…”

“…1,50 One reason why microbiota could recover from exposure to AgNPs may be because the microorganisms can adapt to environmental changes quickly. 50,51 In addition, the EPS, which can act as a barrier to keep AgNPs from reaching bacteria, 48 is increasingly secreted during biofilm development. Thus, the toxicity of AgNPs to microbiota might be reduced with the development of biofilm, which is beneficial for microorganism recovery.…”

Oxygen Nanobubble-Loaded Biochars Mitigate Copper Transfer from Copper-Contaminated Soil to Rice and Improve Rice Growth

“…Copper (Cu) is an essential trace element for plants and humans and is a cofactor for numerous proteins . However, excessive Cu retention in the soil inhibits seed germination, soil microbial diversity, and biomass, , and soil key functions, such as nitrogen fixation. , Cu-contaminated agricultural soil, which is generally from the conversion of abandoned mines to farmlands, fungicides application, and wastewater irrigation, , is environmentally concerning. Moreover, Cu contamination further endangers human health via biomagnification in the food chain.…”