The microbial reduction of NO serves as a "gatekeeper" for NO emissions, determining the flux of NO release into the atmosphere. Estuaries are active regions for NO emissions, but the microbial functions of NO-reducing bacteria in estuarine ecosystems are not well understood. In this study, the N isotope tracer method, qPCR, and high-throughput sequencing were used to analyze NO production, reduction, and emission processes in surface sediments of the Pearl River Estuary. The N isotope tracer experiment showed that the NO production rates declined and the NO reduction potential (R, the ratio of NO reduction rates to NO production rates) increased from upstream to downstream of the Pearl River Estuary, leading to a corresponding decrease of the NO emission rates from upstream to downstream. The gene abundance ratio of nosZ/nir gradually increased from upstream to downstream and was negatively correlated with the water NO saturation. The gene abundance of nosZ II was significantly higher than that of nosZ I in the estuary, and the nosZ II/nosZ I abundance ratio was positively correlated with NO reduction potential. Furthermore, the community composition of NosZ-I- and NosZ-II-type NO-reducing bacteria shifted from upstream to downstream. NosZ-II-type NO-reducing bacteria, especially Myxococcales, Thiotrichales, and Gemmatimonadetes species, contributed to the high NO reduction potential in the downstream. Our results suggest that NosZ-II-type NO-reducing bacteria play a dominant role in determining the release potential of NO from sediments in the Pearl River Estuary. This study provides a new insight into the function of microbial NO reduction in estuarine ecosystems.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.envpol.2023.121732 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The effect of curcumin 1% methanolic extract on the expression of Matrix Metalloproteinase-1, Matrix Metalloproteinase-8, Matrix Metalloproteinase-13, neutrophil, macrophage, lymphocyte counts in induced periodontitis: a randomized controlled trial.
Saudi Dent J
October 2024
Department of Periodontology, Faculty of Dental Medicine, Universitas Airlangga, Surabaya, Indonesia.
Objective: Hailed as one of the most fundamental and important treatment in management of periodontal disease, scalling and root planning has limitations regarding microorganism elimination. Meanwhile, turmeric has been proven to have a therapeutic effect on gingivitis and periodontitis. This study aimed to analyze the impact of curcumin 1% methanolic extract on the expression of Matrix Metalloproteinase-1, Matrix Metalloproteinase-8, Matrix Metalloproteinase -13, neutrophil, macrophage, and lymphocyte number in the gingiva of Wistar rats exposed to ().
View Article and Find Full Text PDFCombination of Sequencing Batch Operation and A/O Process to Achieve Partial Mainstream Anammox: Pilot-Scale Demonstration and Microbial Ecological Mechanism.
Environ Sci Technol
September 2023
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, P. R. China.
In this study, sequencing batch operation was successfully combined with a pilot-scale anaerobic biofilm-modified anaerobic/aerobic membrane bioreactor to achieve anaerobic ammonium oxidation (anammox) without inoculation of anammox aggregates for municipal wastewater treatment. Both total nitrogen and phosphorus removal efficiencies of the reactor reached up to 80% in the 250-day operation, with effluent concentrations of 4.95 mg-N/L and 0.
View Article and Find Full Text PDFNitric oxide (NO) is a highly reactive and climate-active molecule and a key intermediate in the microbial nitrogen cycle. Despite its role in the evolution of denitrification and aerobic respiration, high redox potential and capacity to sustain microbial growth, our understanding of NO-reducing microorganisms remains limited due to the absence of NO-reducing microbial cultures obtained directly from the environment using NO as a substrate. Here, using a continuous bioreactor and a constant supply of NO as the sole electron acceptor, we enriched and characterized a microbial community dominated by two previously unknown microorganisms that grow at nanomolar NO concentrations and survive high amounts (>6 µM) of this toxic gas, reducing it to N with little to non-detectable production of the greenhouse gas nitrous oxide.
View Article and Find Full Text PDFExploring the roles of amylopectin in starch modification with Limosilactobacillus reuteri 121 4,6-α-glucanotransferase via developed methods.
Int J Biol Macromol
July 2023
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China. Electronic address:
Limosilactobacillus reuteri 121 4,6-α-glucanotransferase (GtfBΔN) modifies starch by cleaving (α1 → 4) linkages and introducing non-branched (α1 → 6) linkages to produce functional starch derivatives. Research has mainly focused on GtfBΔN converting amylose (linear substrate), whereas the conversion of amylopectin (branched substrate) has not been studied in detail. In this study, we used GtfBΔN to understand amylopectin modification and performed a set of experiments to analyze this modification pattern.
View Article and Find Full Text PDFMechanism of suspended sludge impact on anammox enrichment in anoxic biofilm through long term operation and microbial analysis.
Water Res
February 2023
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China. Electronic address:
The basic premise of anammox-technical application reliability in municipal wastewater treatment is substantially enriched anammox bacteria. To enrich the anammox, the special interaction mechanism between the suspended sludge (SS) and anoxic biofilm was investigated over three months in a partial denitrification/anammox biosystem subjected to dynamic changes in SS (absence→ presence→ absence). Results show that the introduction of SS significantly decreased the anammox nitrogen removal efficiency (83.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!