Work

Spatiotemporal distribution and potential functions of N2O-reducing bacteria in the waters of the Pearl River Estuary

Year: 2025

Type: article

Abstract: The reduction of N 2 O to N 2 , catalyzed by two kinds of N 2 O-reducing bacteria, is the only known biological pathway of N 2 O sink. However, the distribution and function of N 2 O-reducing bacteria in estuarine waters remains unknown. This study investigated the distribution and community characteristics of two clades of N 2 O-reducing bacteria (clades I and II) and their potential function in the waters of the Pearl River Estuary (PRE). Our results reveal that the gene abundance of the NosZ-II type of N 2 O-reducing bacteria was remarkably higher than the NosZ-I type, specifically 2.29 to 16.41 times higher in summer and 1.63 to 16.68 times higher in winter, indicating that the NosZ-II type should play a major role in reducing N 2 O content of the waters of the PRE. Furthermore, higher nos Z I/ nir and nos Z II/ nir ratios were strongly associated with lower ΔN 2 O concentration. The potential rate of N 2 O reduction exhibited a gradual increase from upstream to downstream. High-throughput sequencing analysis revealed significant differences in the spatial distribution in the N 2 O-reducing bacterial community from upstream to downstream, with Alphaproteobacteria and Bacteroidetes identified as the dominant types of NosZ-I and NosZ-II N 2 O-reducing bacteria, respectively. The community composition of two types of N 2 O-reducing bacteria was both influenced by NO 2 − concentration in summer. Additionally, co-occurrence analysis demonstrated that 76.67 and 95.45% of the connections between the two clades in summer and winter were positive, indicating a synergistic effect of two types of N 2 O-reducing bacteria for N 2 O reduction. This study provides novel insights into the ecological distribution and functional potential of NosZ-I and NosZ-II clades of N 2 O-reducing bacteria in the PRE, revealing their distinct yet complementary roles in mediating N 2 O reduction processes within estuarine waters.

Source: BMC Microbiology

DOI: 10.1186/s12866-025-04037-w

Authors: Hua Xiang, Yiguo Hong, Jiapeng Wu, Aiming Long

Institutions: Weifang University, Guangzhou University, University of Chinese Academy of Sciences

Language: English

Topic: Microbial Community Ecology and Physiology

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Clean water and sanitation, Life below water, Climate action

Open Access status: gold

Estimated APC paid: $2,990