Investigating sources and sinks of N2O expression from freshwater microbial communities in urban watershed sediments

Abstract

Wastewater treatment plants (WWTPs) serve as point-source inputs for a variety of nutrients often dominated by nitrogenous compounds as a result of anthropogenic influence. These effluents can impact biogeochemical cycles in freshwater estuaries, influencing microbial communities in both the water and sediment compartments. To assess the impact of point source nutrients, a transect of sediment and pore water samples were collected from 4 locations in the Little River Sub-watershed including locations above and below the Little River Pollution Control Plant (LRPCP). Variation in chemistry and microbial community/gene expression revealed significant influences of the effluent discharge on the adjacent sediments. Phosphorus and sulfur showed high concentrations within plume sediments compared to the reference sediments while nitrate concentrations were low. Increased abundance of denitrifiers Dechloromonas, Dok59 and Thermomonas correlating with increased expression of nitrous-oxide reductase suggests a conversion of NO to N within the LRPCP effluent sediments. This study provides valuable insight into the gene regulation of microbes involved in N metabolism (denitrification, nitrification, and nitrite reduction to ammonia) within the sediment compartment influenced by wastewater effluent.

Exploring bacterial pathogen community dynamics in freshwater beach sediments: A tale of two lakes

“…Expression of nar/napB and norB in KV showed 50% upregulation, and 30% upregulation for nosZ , all significantly differentially expressed compared with BR ( p < 0.05). Denitrifying genes with high expression levels such as these at KV are comparable to sediment sampled at a discharge zone of a local wastewater treatment plant (Weisener et al ., ). Because there is such high expression for denitrification suggests that excessive amounts of bioavailable nitrate are present at KV beach for microbial utilization.…”

“…This nitrate could potentially be sourced from either faecal contamination (i.e. wildlife excrement) or high levels of fertilizer runoff from agricultural or residential landscapes that deposits in these low-energy shorelines (Melton et al, 2014;Weisener et al, 2017). On the other hand, BR showed higher expression of transcripts encoding for assimilatory nitrate reduction to ammonia, ANRA (nirA; 15% at BR vs. 4% at KV) and N fixation (nifDH; 33% at BR vs. 3% at KV), both pathways leading to the production of ammonia.…”

“…metabolic status) of the community. The advancement of transcriptomic technology, however, provides higher resolution to observe functional gene expression (Weisener et al, 2017;Reid et al, 2018;Falk et al, 2018). Thus, the insight we gain from messenger RNA (mRNA) can complement taxonomic surveys because it allows us to investigate the functioning community (Goltsman et al, 2015;Crovadore et al, 2017;Zhang et al, 2017), improving our understanding of a microbial system.…”

Insight into the nitrogen accumulation in urban center river from functional genes and bacterial community

“…Nowadays, urban water quality degradation had been observed in developed and developing countries [6,9]. Stress to local water resources had become one of the biggest concerns associated with urbanization [1,10]. Therefore, improving urban river water quality, especially elimination of black-odor phenomenon in rivers, is an urgent need for sustainable city development.…”

Regulation and expression of immunosuppressants compounds from a microbial source

“…Amongst the microorganisms, contagious classes are discovered to be at the highest chain of importance regarding the company of bioactive standards. Taking into account this data and clinical requests, the current examination was intended to investigate the dirt parasitic vegetation for the attendance of clinically expected bioactive standards [3,4].…”